Bot. Bull. Acad. Sin. (1995) 36: 259-279

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

A revision of Elatostema (Urticaceae) of Taiwan

Yuen-Po Yang^1,2, Bing-Ling Shih¹, and Ho-Yih Liu¹

¹Department of Biology, National Sun Yat-Sen University, Kaohsiung, Taiwan, Republic of China

(Recevied August 14, 1995; Accepted September 26, 1995)

Abstract. Fifteen species of Elatostema are recognized and described in Taiwan. Six of them are new species, namely, Elatostema acuteserratum Shih & Yang, Elatostema multicanaliculatum Shih & Yang, Elatostema rivulare Shih & Yang, Elatostema subcoriaceum Shih & Yang, Elatostema strigillosum Shih & Yang, and Elatostema villosum Shih & Yang. Line drawings of ten species are provided.

Keywords: Elatostema; Taiwan; Taxonomy; Urticaceae.

Introduction

The only revisionary work of Urticaceae of Taiwan available was made over two decades ago by Huang (1971). Some taxonomic literature relevant to members of this family have since been published, (e.g., Liu and Huang, 1976; Shih et al., 1995; Wang, 1980; Ying, 1988) and many specimens have been added to the herbaria on this island. It is therefore imperative to provide a new revision for this family. Elatostema is here revised first because it is the largest genus of the family in Taiwan.

ELATOSTEMA Forster & Forster f. nom. cons.

Monoecious or dioecious herbs; stems mostly succulent, herbaceous, rarely woody at base, simple to many branched. Leaves alternate, with or without reduced leaves (nanophylls) opposite to normal ones, sessile to short petiolate, stipulate; lamina somewhat flush with the stem, very unequal-sided at base, the proximal half facing the stem narrower, mostly chartaceous, rarely subcoriaceous to coriaceous, mostly with somewhat dense linear cystoliths on both sides or mostly on adaxial side, rarely without cystolith, trinerved to triplinerved or penninerved, coarsely serrate to nearly entire; stipules intrapetiolar, two at a node, the stipule of the reduced leaf opposite to the normal one's, usually caducous, rarely deciduous or persistent. Inflorescences mostly of many-flowered discoid heads, usually with a well-developed receptacle, rarely 1_3-flowered; heads usually two-valved, each valve including several glomerules which consist of several flowers and are subtended by a few large bracteoles; flowers sessile to long-pedicellate, mostly subtended by small bracteoles. Male flowers with (3_)4_5 sepals; sepals connate at base, the segments slightly imbricate, usually corniculate or shortly horned below the apex; stamens (3_)4_5; rudimentary ovary small. Female flowers with 3_5 or nearly com

pletely reduced sepals; staminodes small, 3_5, scale-like, usually very small when blooming, becoming larger during fruiting, rarely absent; stigma penicillate, ovary straight. Achenes circular in cross section, mostly with longitudinal ribs, rarely smooth, usually dispersed by reflexing staminodes.

About 350 species in the world (Wang, 1980); fifteen species found in Taiwan.

Key to Species in Taiwan

1. Plants with nanophylls 9. E. parvum

1. Plants without nanophyll.

2. Female inflorescences 1-flowered, less than 2.5 mm wide; leaves oblong or obovate, 9_18 mm long, margins with 3_4(_5) obtuse teeth 14. E. trilobulatum

2. Female inflorescences many-flowered, more than 3 mm wide; leaves usually more than 20 mm long, margins with more than 6 teeth.

3. Plants less than 20 cm high; lower parts of main stems less than 3 mm in diameter.

4. Stems glabrescent to glabrous.

5. Stems quadrangular, greenish 5. E. hypoglaucum

5. Stems semiterete, deeply brown-red to green 7. E. microcephalanthum

4. Stems densely hairy.

6. Leaves with long, soft hairs 15. E. villosum

6. Leaves with short, rigid hairs 12. E. strigillosum

3. Plants more than 30 cm high; lower parts of stems more than 5 mm in diameter.

7. Leaves glabrous or nearly so.

8. Leaf margin of proximal half entire (at least at lower portion).

9. Leaf margin sharply toothed; stigmatic hairs unicellular 2. E. edule

²Corresponding author.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

per parts, lateral-compressed, widely depressed-obovoid, ca. 1.6 mm long, 1.9 mm wide, with 5 sepals, the sepals connate about half way, valvate, cymbiform, ca. 2 mm long, 0.9 mm wide, corniculate, the stamens 5; pedicels terete, up to 2.4 mm long; bracteoles ciliolate at upper margins and apex, obliquely shallowly cymbiform, ca. 3.7 mm long, 0.7 mm wide. Female flowers with 4 rudimentary sepals; stigma formed with septate hairs, penicillate, slightly longer than the ovary; ovary ellipsoidal, ca. 0.4 mm long, 0.15 mm wide; staminodes 4, rudimentary, enlarged when fruiting; bracteoles linear-lanceolate, ca. 1mm long, 0.16 mm wide. Achenes ellipsoidal, ca. 0.75 mm long, 0.28 mm wide, with 12 ribs.

Additional specimens examined. TAITUNG HSIEN: Lanyu, Shih 2768, 3407 (NSYSU); Chang 17429, 17440, 17753, 19241 (PPI).

Distribution. Endemic to Island Lanyu. Found along ravines, on shady and moist forest floors. Flowering in spring and autumn.

Notes. This species is related to Elatostema hirtellipedunculatum Shih & Yang, but can be distinguished by its glabrous leaves and entire involucre of female inflorescences. So far, it is known only from Island Lanyu.

2. Elatostema edule C. Robinson, Philip. J. Sci. Bot. 5: 531. 1910; Liu & Huang in Li et al., Fl. Taiwan 2: 179. 1976, p. p.; Ying, Coloured Ill. Fl. Taiwan 3: 454, quoad photo 554, excl. f. 865. 1988, p. p. Figure 2

Elatostema platyphyllum auct. non Wedd.: Ying, Coloured Ill. Fl. Taiwan 3: 456, quoad photo 555. 1988, p. p.

Perennial monoecious herbs; stems very succulent, quadrate-angular, prostrate at lower parts, ascending toward apex, up to 2 m long, 1.5 cm thick, branched, glabrous, greenish, slightly geniculate. Leaves alternate, distichous, sessile to short-petiolate; lamina membranous to herbaceous, glabrous, with up to 0.7 mm long cystoliths densely on upper surface and absent from lower surface, deep green to green on adaxial side, pale green to light green on abaxial side, asymmetrically elliptic to narrowly oblong or oblong, 10_23(_25) cm long, 3_7.5(_8.0) cm wide, the base of the distal half semi-cordate with an earlike limb, the margins crenate to serrulate along the distal half above one-third, almost entire or sometimes 1_3-toothed near apex along the proximal half, the apex cuspidate to acuminate-caudate, entire or rarely inconspicously 1_2-toothed, the semi-triplinerves prominent beneath, the secondary veins 5_7 at the distal half, 3_4 at the proximal half; petioles up to 5 mm long; stipules 2, opposite, caducous, glabrous, greenish with brownish spots, lanceolate- cymbiform, up to 2.5 cm long. Inflorescences sessile to short-pedunculate, whitish-green, slightly minute-puberulent outside, elliptic- to oblong-discoid, the male ones 1.0_3.0 × 0.8_1.5 cm in diameter, with a glabrous, 3_15 mm long peduncles, the female ones up to 25 × 16 mm in size, sessile or subsessile; bracts slightly minute-puberulent, completely connate into an unlobed,

9. Leaf margin obtusely toothed; stigmatic hairs multicellular 13. E. subcoriaceum

8. Leaf margin of proximal half serrate.

10. Achenes distinctly 12-ribbed; male flowers hairy on the abaxial side 1. E. acuteserratum

10. Achenes indistinctly 6-ribbed; male flowers glabrous 8. E. multicanaliculatum

7. Leaves distinctly hairy.

11. Stems densely hirsute (especially at nascent parts) 6. E. lineolatum var. majus

11. Stems nearly glabrous to glabrescent.

12. Leaf-apices entire.

13. Leaves sparsely hirsute; achenes distinctly 8-ribbed 3. E. herbaceifolium

13. Leaves hirtellous hairs; achenes unribbed 4. E. hirtellipedunculatum

12. Leaf-apices serrulate.

14. Distal half of leaf base earlike, across petiole or midrib 10. E. platyphylloides

14. Distal half of leaf base shallowly cordate, not across petiole or midri 11. E. rivulare

1. Elatostema acuteserratum Shih & Yang, sp. nov.

Figure 1

Species nova affinis Elatostemati hirtellipedunculato Shih & Yang, sed differt lamina glabra nec hirsuta, bractea feminea integra nec lobata.—TYPE: Taiwan. Taitung Hsien: Lanyu, Shih 3187 (holotype: NSYSU; isotypes: HAST, TAI, TAIF).

Perennial monoecious or dioecious herbs, slightly branched, erect or ascending, up to 80 cm long; stems terete, branchlets slightly geniculate, glabrous, with very dense cystoliths in exsiccate specimens, somewhat dark-green. Leaves alternate, sessile to short-petiolate, stipulate; lamina membranous to thick chartaceous, nearly glabrous, cystoliths minute, densely on adaxial side, densely along veins on abaxial side, lanceolate or narrowly elliptic to elliptic, up to 18 cm long, 5 cm wide, acuminate to caudate at apex, with a (1_)2_5(_6)_serrulate acumen, sharply serrate to dentate at margins, broadly cuneate at base of the distal half, pennierved, with 7_9 pair lateral nerves; petioles semi-terete, canaculiate on upper side, less than 3 mm long; stipules intrapetiolar, persistent, nearly glabrous, ciliolate, narrowly triangular, 1.5_2.3 mm long, acuminate at apex, 1-veined. Inflorescences in discoid heads, sessile or subsessile; male one slightly puberulent outside, ellipsoidal, ca. 12 mm in diameter; female one somewhat puberulent outside, sub-quadrate-discoid, ca. 7 mm in diameter. Male flowers puberulent outside at up

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

Figure 1. Elatostema acuteserratum Shih & Yang, from Shih 3407. A, A flowering branch. B, Leaf (abaxial view). C, Male inflorescence (ventral view). D, Male flower. E, Two male sepals (abaxial view). F, Female inflorescence (ventral view). G, Female flower. H, Female bracteole. I, Achene.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

Figure 2. Elatostema edule C. Robinson, from Shih 3408. A, A flowering branch. B, Leaf (abaxial view). C, Stipules, left: lateral view, right: abaxial view. D, Male inflorescence (ventral view). E, Male flower in blooming. F, Male sepal (abaxial view). G, Female inflorescence (ventral view). H, Female flower. I, Left: staminodes & pedicel, right: bracteole (abaxial view). J, Achene.

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

narrowly oblong to oblong involucre, up to 3 cm long, 1 cm wide in male inflorescences, up to 25 mm long, 10 mm wide in female's. Male flowers obovoid, ca. 2.5 mm long and wide, pedicellate, subtended by bracteoles; bracteoles semi-transparent, with minute linear cystoliths dispersed parrallelly to the midvein, cymbiform, ca. 3.5 mm long, the apex ciliolate, truncate or mucronate, the margins entire, minutely hirsute on one-third of the abaxial veins; sepals 4, connate halfway, semi-transparent, glabrous, corniculate, cymbiform, ca. 2.3 mm long in blooming flowers, acute at apex; pedicels sparsely puberulent. Female flowers pedicellate, subtended by bracteoles; bracteoles semi-transparent, narrowly oblong, ca. 0.9 mm long, 0.3 mm wide when blooming, enlarged when fruiting, the upper margins and apex ciliolate, the lower margins entire, the abaxial veins puberulent subterminally; sepals 4, free, rudimentary; staminodes 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ellipsoidal, ca. 0.4 mm long, 0.2 mm wide. Achenes ellipsoidal, ca. 0.7 mm long, 0.35 mm wide.

Specimens examined. TAITUNG HSIEN: Lanyu, Kawakami & Nakahara 1052 (TAIF, paratypus), Shih 2747, 2754, 2766, 3165, 3169, 3408 (NSYSU); Lutao, Yang 6856 (NTNU).

Distribution. Batan islands. Taiwan, found on Islands Lanyu and Lutao, growing along streams, ravines, and on moist forest floors.

Notes. This species is confined to Islands Lutao, Lanyu of Taiwan and Island Batan of the Philippines. Liu and Huang (1976) and Ying (1988) reported that E. edule is widely distributed in Taiwan. Wang (1980) also reported its occurrence in Hainan Province, China. However, the plants they referred to belong to Elatostema platyphylloides Shih & Yang (Wilmot-Dear, 1995, pers. comm.).

3. Elatostema herbaceifolium Hayata, Icon. Pl. Formosa. 6: 57. 1916. "herbaceifolia"; Liu & Huang in Li et al., Fl. Taiwan 2: 179, pl. 257. 1976; Wang, Bull. Bot. Lab. N.E. Forest. Inst., Harbin. 4(7): 67. 1980; Ying, Coloured Ill. Fl. Taiwan 3: 456, excl. photo 556. 1988, excl. syn. Figure 3

Pilea melastomoides auct. non (Poir.) Wedd.: Ying, Coloured Ill. Fl. Taiwan 3: 434, quoad photo 542. 1988.

Perennial herbs; stems terete, pendent or ascending, usually rooting at lower parts, several-branched, nearly glabrous, pale-green, sometimes brownish-red at lower parts, up to 70 cm long, 5 mm thick. Leaves alternate, distichous, sessile to short-petiolate, stipulate; lamina membranous to chartaceous, slightly hirsute and with dense vermicular, 0.2_0.3 mm long cystoliths on adaxial sides, sparsely minute-hirtellous and with dense cystoliths on abaxial side, green on adaxial side, pale-green on abaxial side, asymmetrically narrow-elliptic to elliptic, up to 15 cm long, less than 5 cm wide, the base of the distal half acute to rounded, the margins very sparsely ciliolate, sharply serrate, the apex with an entire acumine, the

penninerves with 4_5 pairs of lateral nerves, articulated with secondary nerves; petioles up to 5 mm long; stipules 2, opposite, caducous, 1-nerved, minutely hirtellous on abaxial nerves, glabrous on adaxial sides, minute-ciliolate, greenish, lanceolate-cymbiform, ca. 5 mm long. Female inflorescences sessile or subsessile, greenish to green, slightly puberulent outside, subquadrate, up to 15 mm in length and 13 mm in wideth when fruiting; bracts slightly puberulent, connate into a narrowly oblong or lanceolate involucre, up to 10 mm long, 2.5 mm wide. Female flowers short pedicellate, subtended by bracteoles; bracteoles puberulent at apex and subapex, semi-transparent, sub-quadrate, ca. 1.3 mm long, 0.46 mm wide at apex and 0.31 mm wide at base, truncate and ciliolate at apex; sepals 3, minute, subequal, ciliolate at margins and apex, triangular, ca. 0.23 mm long, 0.15 mm wide when fruiting; staminodes 3, minute, enlarged when fruiting; stigma formed with less than 7 simple hairs, penicillate, ca. 0.25 mm long; ovary glabrous, ellipsoidal, ca. 0.2 mm long, 0.1 mm wide. Achenes conspicously 8-ribbed, whitish to brown, ellipsoidal, ca. 0.7 mm long, 0.3 mm wide.

Specimens examined. TAIPEI HSIEN: Bunzangun, Suzuki 18446 (TAI). TAOYUAN HSIEN: Kuanhsi-Fusing, Huang 4815 (TAI); Rarashan, Shih 3108, 3228 (NSYSU). NANTOU HSIEN: Peishan-keng, s.d., Ito s. n. (TAIF); Hsinyi Hsiang, Tili, Shih 2967 (NSYSU); Tungpu, Shih 2972 (NSYSU). CHIAYI HSIEN: Alishan Highway, Shih 2954 (NSYSU); Chiaoliping-Juili, Yang 3571 (TAI); Tapu Shiang, Shih 2728 (NSYSU). KAOHSIUNG HSIEN: Chaishen Shiang, Shih 3327 (NSYSU). TAITUNG HSIEN: Chipen Logging Trail, Shih 3272 (NSYSU).

Distribution. Mainland China. Taiwan, found at low to medium altitudes, mostly growing in ravines, or on moist forest floors near ravines.

Notes. Male flowers of this species have never been found.

4. Elatostema hirtellipedunculatum Shih & Yang, Bot. Bull. Acad. Sin. 36: 160, f. 3. 1995. "hirtelliped-unculata" .

Perennial monoecious herbs; stems suberect or ascending, sometimes suspending from moisture rocks, often simple branched, canaliculate at the side opposite to the substrate, somewhat hirtellous at nascent parts, soon glabresccent or nearly glabrous, red-brown or whitish-green, up to 1 m long, 8 mm thick. Leaves alternate, sessile to subsessile, rarely short-petiolate, distichous; lamina chartaceous, somewhat hirtellous on both sides and with somewhat dense, 0.15_0.35 mm long cystoliths on upper surface, sometimes very sparse cystoliths near the margins, light yellowish-green to green on adaxial side, pale-greenish on abaxial side, narrowly asymmetrical-elliptic to oblique-ovate, up to 20 cm long, 1.5_7.0 cm wide, the base of the distal half rounded, the margins entire at least 1/3 lower part of the distal-half and 1/2 lower part of the prximal-half, dentate to crenate or crenulate at other parts,

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

Figure 3. Elatostema herbaceifolium Hayata, from Shih 3327. A, A fruiting plant. B, Leaf (abaxial view). C, Female inflorescence (sub-ventral view). D, Bracteole (abaxial view). E, Female flower. F, Achene.

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

sometimes entire throughout, the apex long-acuminate to long-caudate, the acumen entire, up to 5 cm long, the palmate-nerves, semi-triple-nerves and penninerves prominent beneath, the secondary veins 4_7 pairs; petioles 0_2 mm long; stipules 2, opposite, persistent, white-greenish, subulate, 2_5 mm long. Inflorescences 1_2 at nodes, sometimes simple-branched, greenish-white, somewhat puberulent outside, discoid, the male ones ellipsoidal, 7.0_18.0 × 7.0_12.0 mm in diameter, the peduncles somewhat densely hirtellous, (1_)1.5_4.5(_5) cm long, the female ones ellipsoidal, up to 8 × 6 mm in size when fruiting, sessile or subsessile, rarely with a peduncle of 5_8 mm long; bracts somewhat puberulent, free or connate at base only, ovate to ellptic, up to 9 mm long, 7 mm wide in male inflorescences, almost completely connate into an asymmetrical involucre with 6 teeth of ca. 2 mm long in female inflorescences. Male flowers subtended by bracteoles, ca. 3.5 mm long, 3 mm wide, pedicellate; bracteoles semi-transparent, corniculate, cymbiform, up to 6 mm long, acute to acuminate, the margins entire or somewhat ciliate near the apex, glabrous; sepals 5, connate at base, semitransparent, glabrous, corniculate, cymbiform, acute at apex; pedicels glabrous, ca. 4.5 mm long. Female flowers subtended by bracteoles, pedicellate; bracteoles semi-transparent, linear, ca. 2.5 mm long, 0.3 mm wide when blooming, the upper margins and apex fimbriate, the lower margins entire; sepals rudimentary; staminodes 5, minute, enlarged when fruiting; stigmas penicillate; ovary glabrous, ovoid. Achenes ovoid, ca. 1 mm long.

Specimens examined. TAIPEI CITY: Peitou, 1908, Kawakami & Sasaki s.n (TAI). ILAN HSIEN: Wushihpi, 1992, Suao, Ying s.n. (NTUF). TAITUNG HSIEN: Chipen Logging Trail, Shih 3269, 2599, 2645 (NSYSU); Taiyuan, Shih 2787 (NSYSU); Dutwoshan, Shih 2736 (NSYSU); Lanyu, Shih 3400 (NSYSU). HUALIEN HSIEN: Chingshuishan, Shih 3314 (NSYSU); Chimay, Shih 3257 (holotype: NSYSU; isotypes: HAST, TAI, TAIF).

Distribution. Endemic; found in vicinity of Taipei, the eastern part of the island, and Island Lanyu at low to medium altitudes. Mostly growing along streams, ravines, sometimes on moist forest floors or rocky places.

Notes. This species bears a strong superficial resemblance to Elatostema herbaceifolium Hayata because of their similarity in leaf shape and size. However, the former has leaves and stems with very sparse, short hairs and leaf-teeth with obtuse to rounded tips, whereas the latter has leaves and stems with many long-hirsute hairs, and leaf-teeth with very sharp tips.

5. Elatostema hypoglaucum Shih & Yang, Bot. Bull. Acad. Sin. 36: 162, f. 4. 1995. "hypoglauca".

Monoecious perennial slender herbs; stems juicy, ascending, quadrate with distinct angles, often simple-branched, sparsely puberulent at nascent parts, soon glabresccent, greenish, 15_25 cm high, rarely up to 35 cm

high, 1_2 mm thick. Leaves alternate, sessile to subsessile, distichous; lamina membranous, very sparsely puberulent or mostly glabrous, with somewhat dense cystoliths on upper surface, very sparsely puberulent on lower surface, light green on adaxial side, pale-green or white-greenish on abaxial side, narrowly elliptic, obovate or oblong, (1.5_)2.0_3.5(_5.5) cm long, (0.5_)1.0_1.5(_2.0)cm wide, semi-cordate or semi-rounded at base, sparsely minutely ciliate or without and dentate or crenate at margins, acute at apex, minutely ciliate and acute or obtuse at the tip of apex, semi-triplinerved or pennierved, the nerves elevated beneath and impressed above, the secondary veins 2_3 pairs; stipules caducous or deciduous, ciliate near apex, entire at lower margins, glabrous on adaxial sides, minutely puberulent on abaxial side, greenish white, lanceolate, ca. 2 mm long, 0.5 mm wide. Inflorescences greenish, somewhat minutely puberulent outside, disclike, the male ones ellipsoidal, ca. 7 mm in diameter, with sparsely minute-puberulent peduncles to 4 cm long, the female ones usually in a oblique-quadrate outline, up to 4 × 3 mm in size when fruiting, sessile or subsessile; bracts sparsely minute-puberulent, completely connate into an unlobed, oblong involucre, up to 3.5 mm long, 2 mm wide in female inflorescences. Male flowers subtended by bracteoles, ca. 1 mm long and wide, pedicellate; sepals 5, connate at base, semi-transparent, somewhat minute-puberulent outside, mostly corniculate, cymbiform, acute at apex; pedicels glabrous. Female flowers subtended by bracteoles, pedicellate; bracteoles semi-transparent, cymbiform, acute, fimbriate at the upper half, entire at the lower half, the abaxial veins puberulent at upper half; sepals 3, free, very minute or rudimentary; staminodes 3, minute, enlarged when fruiting; stigmas penicillate, deciduous; ovary glabrous, ovoid. Achenes ovoid or ellipsoidal, ca. 0.7 mm long, 0.4 mm wide.

Specimens examined. TAIPEI HSIEN: Saukan & Kyanrawa, Suzuki 6999 (TAI). ILAN HSIEN: Taipingshan, Suzuki 545 (TAI). TAOYUAN HSIEN: Rarashan, Shih 3111 (holotype: NSYSU; isotypes: HAST, TAI, TAIF), 3121 (NSYSU). NANTOU HSIEN: Randaishan, Kawakami & Hayata 7129 (TAIF). CHIAYI HSIEN: Mt. Morrison, Kawakami & Mori 1987 (TAIF).

Distribution. Endemic; found at medium altitude, growing on moist forest floors or beside streams and ravines.

Notes. This species is related to Elatostema cuspidatum Wedd., but can be distingushed by a combination of the following characters: plants dwarf, less than 35 cm high; stems slender; leaves with obtuse teeth; and male inflorescence with a distinct peduncle. This species is also similar to E. microcephalanthum Hayata, but can be distinguished by its quadrate-angular and sparsely puberulent stems and completely connate female involucres.

6. Elatostema lineolatum Wight var. majus Wedd., Arch. Mus. Hist. Nat. Paris 9: 312. 1856 et in DC., Prodr. 16 (1): 182. 1869; Thwaites, Enum. Pl. Zeyl. 260. 1864; Wang, Acta Phytotax. Sin. 28 (4): 309. 1990; Yamazaki, J. Jap. Bot. 70(3): 176. 1995.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

Pellionia scabra auct. non Benth.: Ying, Coloured Ill. Fl. Taiwan 3: 445, quoad photo 550. 1988.

Monoecious or dioecious subshrubs; stems erect or ascending, terete, branched, hirsute, gray-brown, up to 1 m high, 5.5 mm thick. Leaves alternate, sessile or subsessile, stipulate; lamina chartaceous, pubescent and with dense, up to 0.3 mm long cystoliths on adaxial side, with apressed hairs along veins and without cystolith on abaxial side, green on adaxial side, pale-green on abaxial side, asymmetrically narrowly elliptic, oblong to lanceolate, up to 15.5 cm long, 4.5 cm wide, the base of the distal half acute, the margins sharply serrate, the apex acuminate, the semi-triplinerves articulated with lateral and secondary nerves; stipules 2, opposite, deciduous, hirsute at abaxial side, mostly along veins, ciliolate at margins, greenish, narrowly triangular, the one of reduced leaf 1-veined , ca. 5.2 mm long, 0.8 mm wide, the other of normal leaf 2-veined, ca. 5.8 mm long, 1.3 mm wide. Male inflorescences subsessile, ellipsoidal-discoid, up to 5 × 4 mm in size; bracts connate into a oblong involucre, the involucre hirsute outside, up to 5 mm long, 2 mm wide. Female inflorescences sessile or subsessile, whitish-green, hirsute outside, ellisoidal-discoid, up to 8 × 6 mm in size when fruiting; bracts hirsute, connate into a narrowly oblong involucre, up to 8 mm long, 2 mm wide. Male flowers hirsute outside, lateral-compressed, widely obovoid, up to 1.6 mm long, 1.4 mm wide, pedicellate, subtended by bracteoles; sepals 4, valvate, dimorphic, unequal, obovate-cymbiform of larger ones, ca. 1.2 mm long, 1.1 mm wide, elliptic-cymbiform of smaller ones, ca. 1.2 mm long, 0.56 mm wide; bracteoles cymbiform, ca. 1.6 mm long, 0.45 mm wide; pedicels ca. 2.2 mm long. Female flowers pedicellate, subtended by bracteoles; bracteoles semi-transparent, ciliate at upper margins and apex, densely hirsute at abaxial side, linear, ca. 1.5 mm long, 0.2 mm wide; sepals 3, minute; staminodes 3, minute, enlarged when fruiting; stigma penicillate, formed with less than 5 hairs; ovary glabrous, ellipsoidal, ca. 0.3 mm long, 1.9 mm wide. Achenes brown, conspicuously 8-ribbed, ellipsoidal, ca. 0.65 mm long, 0.34 mm wide.

Specimens examined. TAIPEI CITY: Muchihshan, Kuo 6491 (TAI); TAIPEI HSIEN: Shihmen, Shih 3218 (NSYSU); Wulaishan, Shih 3398 (NSYSU). KEELUNG CITY: 1916, Hayata s. n. (TAIF). TAOYUAN HSIEN: Tachi, 1934, Sasaki s. n. (TAI). HSINCHU HSIEN: Wutzushan, 1914, Ito s. n. (TAIF). TAICHUNG HSIEN: Lienhuachi, 1936, Mori s. n. (TAI); Lishan, 1977, Kuo s. n. (TAIF). CHIAYI HSIEN: Alishan Highway, Shih 2953 (NSYSU); Funchifu, Huang & Huang 15951 (TAI). TAINAN HSIEN: Kuantzuling, 1918, Shimada s. n. (TAIF). KAOHSIUNG: Laulong Logging Trail, Shih 2640 (NSYSU); Meilong, Shih 2635 (NSYSU); Shanping, 1995, Lin s. n. (NSYSU); Shihshan, Shih 3383 (NSYSU). PINGTUNG HSIEN: Wuweishan, 1920, Matuda s. n. (TAIF). TAITUNG: Chihpen, Shih 2588 (NSYSU); Dutwoshan, Shih 2739 (NSYSU); Lichai Logging Trail, Shih 3354 (NSYSU); Tajen, Shih 3287 (NSYSU); Tanan, Shih 2576 (NSYSU); Tawu, Shih 3289 (NSYSU).

Distribution. Distributed in Nepal, Bhutan, India, and China. Taiwan, found at low to medium altitudes throughout the island, growing along trails, in moist forest floors and in ravines. Flowering from late October to next May.

Notes. This variety is characterized by its linear-lanceolate leaves, and densely hirsute stems and leaves. The typical variety is distributed in India, Ceylon, Himalaya, and Burma (Hara and Williams, 1979). Elatostema lineolatum ver. majus has leaves with larger, more coarsely serrate, margins, whereas the typical variety has leaves with conspicuously but shallowly crenate or serrate margins (Grierson and Long, 1983).

Hooker f. (1888) cited a variety `major' of Elatostema lineolatum and attributed it to Thwaites, which was followed by many, such as Matsumura and Hayata (1906), Hayata (1916), Yamamoto (1925), Liu and Huang (1976), Wang (1980), and Ying (1988). After checking Thwaites' (1964) "Enumeration of Ceylon Plants", we found that he did not describe the variety. In fact all varieties of this species in his book folllowed Weddell's treatment (1856).

7. Elatostema microcephalanthum Hayata, Icon. Pl. Formosan. 6: 59. 1916. "microcephalantha"; Wang, Bull. Bot. Lab. N. E. Forest. Inst., Harbin 4(7): 43. 1980. Figure 4

Perennial monoeciuos herbs; stems ascending, prostrate at base, usually rooting at lower parts, branched, canaliculate at upside, glabrous, deeply brown-red, brownish-green to green, up to 60 cm long, 3 mm thick. Leaves alternate, sessile to short-petiolate, stipulate; lamina membranaceous, sparsely to slightly hirsute and with slightly dense, ca. 0.3 mm long cystoliths on adaxial side, sparsely hirsute along veins and without cystolith on abaxial sides, deep-green on adaxial side, pale-green on abaxial side, asymmetrically obovate, ovate to obovate-lanceolate, 1.5_6.0 cm long, 0.8_2.0 cm wide, the base of the distal half rounded to semi-cordate, the margins slightly minute-ciliolate, obtusely serrate, the apex obtusely acute to acutely acuminate, the semi-triplinerves articulated with lateral and secondary nerves; stipules 2, opposite, persistent, 1-nerved, glabrous, greenish, lanceolate, 1_2 mm long, the margins minute-ciliolate. Male inflorescences long-pedunculate, up to 8 × 5 mm in size; bracts connate into a narrowly oblong involucre of ca. 8 mm long, 1 mm wide; peduncle up to 4 cm long. Female inflorescences sessile or subsessile when blooming, pedunculate when fruiting, whitish-green, ellipsoidal, up to 6 mm in length and 5 mm in width when fruiting; bracts slightly puberulent, connate into a narrowly oblong involucre, up to 6 mm long, 0.8 mm wide; peduncles up to 1.7 cm long when fruiting. Male flowers hirtellous outside, widely obovate, ca. 1 mm long and wide; sepals 5, hirtellous at abaxial side, subequal, ovate-cymbiform, ca. 2 mm long, 0.7 mm wide, slightly corniculate; pedicels up to 1.5 mm long. Female flowers short pedicellate; sepals 3 or 4, minute, unequal, linear-acicular, 0.1_0.2 mm long; staminodes 3 or 4, minute, enlarged when fruiting; stigma penicillate; ovary

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

Figure 4. Elatostema microcephalanthum Hayata, from Shih 3409. A, Habit. B, Cross section of upper stem. C, Leaf (abaxial view). D, Stipules, left: sub-lateral view, right: abaxial view. E, Male inflorescence (ventral view). F, Male flower in blooming. G, Male sepals (ventral view). H, Female inflorescence (ventral view). I, Male bracteoles, left: sub-lateral view, right: abaxial view. J, Female bracteole (abaxial view). K, Achene with staminodes.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

glabrous, ovoid, ca. 0.4 mm long. Achenes inconspicously 5_ or 6_ ribbed at subapex toward apex, ovoid, ca. 0.7 mm long, 0.3 mm wide; pedicels subquadrate when fruiting.

Specimens examined. TAIPEI HSIEN: Peichatienshan, Shih 3142, 3144, 3148, 3150 (NSYSU). ILAN HSIEN: Chaishiang Bridge, Shih 2876 (NSYSU). TAOYUAN HSIEN: Rarashan, Shih 3103, 3104, 3106 (NSYSU). CHIAYI HSIEN: Alishan, 1912, Hayata s. n. (TI, syntype). KAOHSIUNG HSIEN: Shihshan, Shih 3409 (NSYSU). TAITUNG HSIEN: near Tongho Farm, Shih 3267 (NSYSU).

Distribution. Endemic; found at medium altitude throughout the island, mostly growing in ravines or on moist floors near ravines. Flowering from June to January.

Note. This species is quite common at medium altitude throughout this island. Plants of this species were neglected previously. Its male inflorescences are long-pedunculate. Wang (1980) erroneously indicated that this species has sessile or subsessile male inflorescences.

8. Elatostema multicanaliculatum Shih & Yang, sp. nov. Figure 5

Species nova affinis Elatostemati ficoidi Wedd., sed inflorescentiis discoideis nec sycocarpi.—TYPE: Taiwan.Taoyuan Hsien: Rarashan, Shih 3226 (holotype: NSYSU; isotypes: TAI, TAIF, HAST)

Perennial herbs; stems repent or ascending, usually rooting at lower parts, branched, with 5 or more longitudinal canals, glabrous, greenish, sometimes brown-red at lower parts, up to 80 cm long, 12 mm thick. Leaves alternate, sessile or subsessile, stipulate, alternate, distichous; lamina membranous, sparsely hirsute and with dense ca. 0.2 mm long cystoliths on adaxial side, glabrous and without cystolith on abaxial sides, green on adaxial side, pale-green on abaxial side, asymmetrically elliptic to lanceolate-oblong, usually 5_14(_14.5) cm long, 2.5_5.0(_5.5) cm wide, the base of the distal half semi-cordate, the margins slightly minute-ciliolate, serrulate to coarsely serrate, the apex with a nearly entire, 5_15 mm long acumen, the triplinerves or penninerves articulated with lateral and secondary nerves; stipules 2, opposite, deciduous, 1-nerved, glabrous, greenish, lanceolate, 5_7 mm long, ca. 2 mm wide, the nerve not reaching the apex, the margins minute-ciliolate. Female inflorescences sessile or subsessile, whitish-green, slightly puberulent outside, subquadrate, up to 12 mm in length and 8 mm in wideth when fruiting; bracts slightly puberulent, connate into a narrowly oblong or lanceolate involucre, up to 10 mm long, 2.5 mm wide. Female flowers short pedicellate, subtended by bracteoles; bracteoles semitransparent, narrowly lanceolate, ca. 0.5 mm long, ciliolate at apex, glabrous; sepals 3 or 4, minute, unequal, linear-acicular, 0.1_0.25 mm long; staminodes 3 or 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ovoid, ca. 0.4 mm long. Achenes inconspicously 5_ or 6_ ribbed at subapex toward apex,

ovoid, ca. 0.7 mm long, 0.3 mm wide; pedicel subquadrate when fruiting.

Additional specimen examined. TAOYUAN: Rarashan, Shih 3127 (NSYSU).

Distribution. Endemic; found only at medium altitude around Rarashan area, mostly growing on moist floors near a ravine. Flowering from September to November.

Notes. This species superficially resembles Elatostema ficoides Wedd., but differs from it in having receptacles not enclosing inflorescences and not splitting irregularly when blooming. In contrast, E. ficoides has receptacles forming ficoid heads enclosing inflorescences and splitting irregularly when blooming.

Matsumura and Hayata (1906) indicated the occurrence of E. ficoides in Taiwan, which is doubtful. Such specimens are not available in any herbaria of this island. Dr. Wilmot-Dear (pers. comm., 1995) informed us that some specimens (in K) from Taiwan annotated as "E. ficoides" may belong to this new species.

Male flowers of this species have never been seen.

9. Elatostema parvum (Blume) Miq. in Zoll., Syst. Verz. Ind. Archip. 102. 1854; Chun & Chang, Fl. Hainanica 2: 409. 1965; Wang, Bull. Bot. Lab. N.E. Forest. Inst., Harbin 4(7): 34. 1980.

Procris parvum Blume, Bijdr. 512. 1825.

Elatostema minutum Hayata in J. Coll. Sci. Imp. Univ. Tokyo 25(9): 198, pl. 36. 1908 & Icon. Pl. Formosan. 6: 60, f. 7. 1916; Liu & Huang in Li et al., Fl. Taiwan 2: 181. 1976; HSIEN Ying, Coloured Ill. Fl. Taiwan 3: 458, photo 557, 1988.

Perennial monoecious herbs; stems prostrate or ascending, usually rooting at lower parts, branched, subterete, densely hirsute at nascent parts, glabrscent toward base, slightly dark-green, up to 40 cm long, 3 mm thick. Leaves alternate, sessile or subsessile, stipulate, alternate, distichous; nanophylls opposite the leaves, ovate to obovate, less than 0.4 cm long, deciduous, ciliate, glabrous on adaxial side, slightly hirsute on abaxial side; lamina chartaceous, slightly hirsute on both sides, with ca. 0.2 mm long cystoliths on adaxial sides, without cystolith on abaxial side, green to deep-green on adaxial side, pale-green on abaxial side, asymmetrically obovate, ovate to lanceolate, 1.0_5.5 cm long, 0.5_2.0 cm wide, the base of the distal half rounded to semi-cordate, the margins sharply serrate, the apex acute to acuminate, the triplinerves or penninerves articulated with lateral and secondary nerves to form a reticulated venation; stipules 2, opposite, persistent, 1-nerved, glabrous to glabrescent, greenish, obliquely lanceolate, 3.0_4.0 mm long, the margins ciliolate. Male inflorescences sessile to short-pedunculate, hirsute outside, ellipsoidal, up to 5.0 × 4.0 mm in diameter; peduncules hirsute, up to 5 mm long. Female inflorescences sessile or subsessile, greenish, hirsute outside, ellipsoidal, up to 4.5 × 3.5 mm in diameter when fruiting. Male flowers with 5 sepals, hirtellous outside, obovoid, ca. 2 mm long, 2.5 mm wide. Female flowers with 4 se

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

Figure 5. Elatostema multicanaliculatum Shih & Yang, from Shih 3127. A, A branch. B, Cross section of upper stem. C, Female inflorescence (ventral view). D, Stipules (abaxial view). E, Achene with staminodes, sepals & pedicel.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

teoles semi-transparent, with minute linear cystoliths dispersed parallel to the midvein, cymbiform, ca. 5 mm long, the apex ciliate, truncate or mucronate, the margins entire, minutely hirsute on one-third of the abaxial veins; sepals 4, connate at base, semi-transparent, somewhat puberulent and minutely ciliate near apex, somewhat corniculate, cymbiform, ca. 2.3 mm long in blooming flowers, acute at apex; pedicels sparsely puberulent. Female flowers subtended by bracteoles, pedicellate; bracteoles semi-transparent, narrowly oblong, ca. 0.9 mm long, 0.3 mm wide when blooming, the upper margins and apex fimbriate, the lower margins entire, the abaxial veins puberulent subterminally; sepals 3, free, slightly unequal, narrowly triangular, ca. 0.1_0.3 mm long; staminodes 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ellipsoidal. Achenes ellipsoidal.

Specimens examined. TAIPEI HSIEN: Yin-ho-tung, Wang 2745 (TAI). ILAN HSIEN: Tu-chian, Suzuki 3734 (TAI). HSINCHU HSIEN: Wuchihshan, Liau 404 (TAI). TAICHUNG HSIEN: Maopu-Chinghu, Yang 1323 (TAI). NANTOU HSIEN: Chitou, Ou & Kao 9126 (TAI). CHIAYI HSIEN: Van-lu Shiang, Alisan-Highway, Shih 2948 (NSYSU); The Third Highway (at 353.3 km), Shih 2727 (NSYSU). KAOHSIUNG HSIEN: Shan-ping, 1995, Lin s. n.. TAITUNG HSIEN: Chipen Logging Trail, Shih 2598 (holotype: NSYSU, Isotypes: HAST, TAI, TAIF); Lichai Logging Trail, Shih 3366 (NSYSU); Du-two-shan, Shih 2738 (NSYSU). HUALIEN HSIEN: Tienhsiang, Shimizu & Kao 10613 (TAI).

Distribution. Hainan, China. Distributed almost throughout this island except Hengchun Peninsula from low to medium altitude, mostly growing along streams, ravines, also on moist forest floors.

Notes. This species is widely distributed in Taiwan, except Hengchun Peninsula. It has been erroneously recognized as E. edule C. Robinson for a long time. It is sharply distinct from E. edule in having hairs on plants, serrate tips at apex of leaves, and chartaceous leaves when fresh. In contrast, plants of Elatostema edule are glabrous and have leaves fleshy when fresh and with entire tip at apex.

11. Elatostema rivulare Shih & Yang, sp. nov. Figure 6

Affine Elatostemati platyphylloidi Shih & Yang, sed foliis ovato-elliptica, acumine sparse serrato, inflorescentia feminea lobata nec integra differt.—TYPE: Taiwan. Kaohsiung Hsien: Meishankou, Shih 2613 (holotype: NSYSU; isotypes: HAST, TAI, TAIF)

Perennial herbs; stems slightly woody at base, simple to several-branched, ascending or suberect, sparsely puberulent, glabresccent, green to deep-green or brownish- to brown-green, slightly geniculate, up to 80 cm high, 8 mm thick. Leaves alternate, sessile to subsessile, distichous; lamina chartaceous, slightly hirsute, with densely 0.2_0.3 mm long cystoliths on upper surface, with sparse not more than 0.2 mm long cystoliths on lower surface, green to deep-green on adaxial side, pale green on abaxial

pals; staminodes 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ovoid, ca. 0.4 mm long. Achenes ovoid, ca. 0.5 mm long, 0.3 mm wide.

Specimens examined. TAIPEI HSIEN: Peichatienshan, Shih 3141 (NSYSU). ILAN HSIEN: Fushan, Shih 2828 (NSYSU); Taipingshan, Huang 4988(TAI). TAOYUAN HSIEN: Rarashan, Shih 3105, 3107 (NSYSU). TAICHUNG HSIEN: Lishan, Shih 2890 (NSYSU); Piluchi, Shih 2992 (NSYSU). NANTOU HSIEN: Mt. Morrison, Kawakami & Mori 1986 (TAIF, type of E. minutum Hayata); Nengkaoshan, 1919, Matuda s. n. (TAIF); Tongpu, Shih 2985 (NSYSU). CHIAYI HSIEN: Heisyana, 1914, Hayata s. n. (TAIF). PINGTUNG HSIEN: Tawushan, 1921, Matuda s. n. (TAIF); Wutoushan, Yang 10427 (PPI). TAITUNG HSIEN: Chipentsushan, Yang & Lin 11282 (PPI); Lichai Logging Trail, Shih 3365 (NSYSU). HUALIEN HSIEN: Kiraikei-Asahi, 1919, Matuda s. n. (TAIF); Sarkartang Logging Trail, Shih 3065 (NSYSU); Mt. Taroko, Keng & Kao 2624 (TAI); Tzuen, Shih 3253 (NSYSU).

Distribution. Distributed in Nepal, Northern India, Java, and China. Taiwan found at medium altitude throughout the island, mostly growing on moist floors near ravines.

Notes. This species is characterized by having a nanophyll opposite to a normal leaf.

10. Elatostema platyphylloides Shih & Yang, Bot. Bull. Acad. Sin. 36: 158, f. 2. 1995.

Perennial monoecious or dioecious herbs; stems somewhat woody at base, branched, somewhat hirsute at nascent parts, glabresccent, green, slightly geniculate, distinctly striated in specimens, up to 1.5 m high, 1 cm thick. Leaves alternate, sessile to short-petiolate, distichous; lamina chartaceous, somewhat hirsute, with very dense, 0.3_0.4 mm long cystoliths on upper surface and mostly along veins on lower surface, dark green to green on adaxial side, pale green to light green on abaxial side, narrowly elliptic to oblong, (5_)10_25(_30) cm long, (2_)4_7.5(_8.5) cm wide, the base of the distal half semi-sagittate with a earlike limb which crossing the petiole to the opposite side, the margins ciliate and serrate to serrulate, the apex caudate, ciliate and densely serrulate, the semi-triple-nerves prominent beneath, the secondary veins 4_6 pairs; petioles 0_5 mm long; stipules 2, opposite, caducous, ciliate, glabrous on adaxial side, hirsute on abaxial veins, greenish with minute brown spots, lanceolate-cymbiform, 1.5_2.5(_3) cm long, 3_5.5 mm wide. Inflorescences greenish, somewhat minutely puberulent outside, discoid, the male ones with two ellipsoidal parts, 1.5_3.0 × 1.0_2.5 cm in diameter, the peduncles glabrous, 3_18 mm long, the female ones usually in a butterfly-like outline, up to 7 × 6 mm in size, sessile or subsessile; bracts somewhat minutely puberulent, completely connate into an unlobed, narrowly oblong to oblong involucre, up to 3 cm long, 1 cm wide in male inflorescences, up to 7 mm long, 2 mm wide in female's. Male flowers subtended by bracteoles, pedicellate; brac

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

Figure 6. Elatostema rivulare Shih & Yang, from Shih 2987. A, Habit. B, Leaf (abaxial view). C, Stipules, left: abaxial view, right: sublateral view. D, Female inflorescence (ventral view). E, Female flower. F, Female bracteoles, left: abaxial view, right: abaxial view. G, Staminodes, sepals & pedicel. H, Achene with staminodes & sepals.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

side, narrow-oblong, narrow-elliptic to elliptic, (4_)6_15(_16)cm long, (2_)3_6(_6.5)cm wide, the base of the distal half acute to semi-cordate, the margins ciliolate, serrate, the apex abruptly caudate, ciliolate and sparsely 1_5-serrulate, the semi-triplinerves prominent beneath, the secondary veins 4_6 pairs; stipules 2, dimorphic, opposite, caducous, ciliolate, glabrous on adaxial sides, hirsute on abaxial nerves, greenish, the 1-nerved stipule lanceolate-cymbiform, 13_17.5 mm long, 2_4 mm wide, the 2-nerved stipule obliquely triangular-lanceolate, 13_15 mm long, 3_5 mm wide. Inflorescences greenish, slightly dense-puberulent outside, very thin-discoid, somewhat into a butterfly outline, up to 12 × 8 mm in size, sessile or subsessile; bracts slightly puberulent, completely connate into an unlobed, narrowly oblong to oblong involucre, up to 10 mm long, 4 mm wide. Female flowers short pedicellate, subtended by bracteoles; bracteoles semi-transparent, narrowly oblong, ca. 0.6 mm long, 0.2 mm wide when blooming, the upper margins and apex ciliolate, the lower margins entire, the abaxial sides puberulent; sepals 3, free, subunequal, very minute, not more than 0.2 mm long; staminodes 3, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, slightly compressed, ovoid-ellipsoidal. Achenes ellipsoidal, ca. 0.6 mm long, 0.3 mm wide, 6-ribbed.

Additional specimens examined. TAICHUNG HSIEN: Hsinchayang, Shih 3002 (NSYSU). NANTOU HSIEN: Chitou, Chang 18273 (PPI). KAOHSIUNG HSIEN: Meishankou, Shih 3403 (NSYSU); Shan-ming Bridge, Shih 2814, 3405 (NSYSU). TAITUNG HSIEN: South Cross Highway, Shih 2662 (NSYSU); Tungho Farm, Shih 2797 (NSYSU).

Distribution. Endemic. Distributed at medium altitude, mostly growing along ravines, rare on moist forest floors near ravines. Flowering from Feburary to July.

Note. This new species is very similar to Elatostema platyphylloides Shih & Yang in leaf-texture, but is different from it in having usually elliptic leaves, sparsely serrulate leaf acumene, and larger female inflorescences (up to 12 × 8 mm in size).

12. Elatostema strigillosum Shih & Yang, sp. nov. Figure 7

Species nova affinis Elatostemati delicatulo Wedd., sed caule brevi, breviter strigilloso, foliis magnis obovatis, inflorescentiis minoribus differt.—TYPE: Taiwan. Taitung Hsien: near Tonghou farm, Shih 3268 (holotype: NSYSU; isotypes: HAST, TAI, TAIF)

Perennial herbs; stems terete, prostrate or suspending from the substrate it grows, usually rooting at nodes, several branched, densely strigillous throughout, dark brown-green, less than 20 cm long, 3 mm thick. Leaves alternate, distichous, sessile or subsessile; lamina chartaceous, scabrous on upper surface, densely hirtellous, with dense up to 0.43 mm long cystoliths on upper surface and along veins beneath, deep green to green on adaxial side, pale green on abaxial sides, asymmetrically obovate or oblong-

obovate, 9_25 mm long, 5_11 mm wide, the base of the distal half acute to obtuse, the margins ciliolate, 1_4-serrate at proximal half and 3_5-serrate at distal half near subapex, entire ca. halfway to the base, the apex acute, ciliolate, the semi-triple-nerves slightly raised beneath, the lateral nerves 2_3 pairs; stipules 2, opposite, persistent, ciliolate, glabrous on adaxial sides, hirtellous on abaxial side, greenish at nascent parts and brown at older parts, narrowly triangular, less than 1.8 mm long. Female inflorescences sessile or subsessile, greenish, turning into brownish with deep brown dots when fruiting, densely puberulent outside, elliptic-discoid, up to 3.5 mm in length and 2.5 mm in width; bracts densely puberulent, incompletely connate into a narrow-elliptic involucre, up to 3 mm long and 1 mm wide. Female flowers subtended by bracteoles, short-pedicellate; bracteoles semi-transparent, narrowly oblong-cymbiform, ca. 0.7 mm long, 0.25 mm wide when fruiting, the margins ciliolate, the abaxial side puberulent; sepals rudimentary, with 1_2 minute hairs on each one; staminodes 3 or 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ovoid. Achenes ovoid, ca. 0.6 mm long, 0.25 mm wide, with 8 winglike ribs.

Additional specimen examined. TAITUNG HSIEN: near Tungho Farm, Shih 2803 (NSYSU).

Distribution. Endemic; found in a ravine. Flowering from June to October.

Notes. This new species is closely related to Elatostema delicatulum Wedd., but differs from it by having longer stems, larger leaves and smaller inflorescences. This new species is also similar to E. villosum Shih & Yang, but differs from it by having smaller leaves, shorter hairs, and smaller inflorescences. Male flowers of this new species are unknown.

13. Elatostema subcoriaceum Shih & Yang, sp. nov. Figure 8

Species nova affinis Elatostemati eduli C. Robinson, sed caule profunde viridi, foliis oblique-ellipticis, inflorescentiis masculis minoribus, ca. 1.8 cm. nec 3 cm. diametro differt.—TYPE: Taiwan. Taitung Hsien: Lanyu, Shih 3188(holotype: NSYSU; isotypes: HAST, TAI, TAIF).

Perennial monoecious herbs; stems subterete, aggregated, stout, erect or ascending, usually several-branched, glabrous, deep-green, up to 70 cm long, 7 mm thick. Leaves alternate, subsessile to short petiolate, distichous; lamina chartaceous to subcoriaceous, glabrous, with dense up to 0.5 mm long cystoliths on both surfaces, deep green to green on adaxial side, pale green on abaxial side, asymmetrically narrow-elliptic to elliptic, 6_21(_24) cm long, 3_7(_8) cm wide, the base of the distal half rounded, the margins dentate or crenate, entire at least halfway toward base at the proximal half and one-third toward base at the distal half, the apex long acuminate to caudate, usually entire, sometimes 1_2-denticulate, the nerves prominent beneath, the secondary veins 4_8(_9) of the distal half and

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

Figure 7. Elatostema strigillosum Shih & Yang, from Shih 3268. A, Habit. B, Female inflorescence (ventral view). C, Female bracteoles, left: abaxial view, right: abaxial view. D, Female flower. E, Achene with staminodes, sepals, pedicel & bracteole.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

Figure 8. Elatostema subcoriaceum Shih & Yang, from Shih 3188. A, Habit. B, Male inflorescence (ventral view). C, Male flower. D, Male sepals (ventral view). E, Male bracteoles (sub-lateral view). F, Female inflorescence (ventral view). G, Female flower. H, Female bracteole, left: abaxial view, right: abaxial view. I, Achene.

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

3_6 of the proximal half; petioles glabrous, up to 1 cm long; stipules 2, opposite, caducous or deciduous, glabrous on both sides, brown, lanceolate, triangular or narrow-elliptic, up to 14 mm long, 3 mm wide. Male inflorescences subsessile to short petiolate, greenish, nearly glabrous, elliptic-discoid, up to 18 mm long, 16 mm wide, the peduncle up to 10 mm long. Female inflorescences sessile or subsessile, greenish, slightly puberulent outside, elliptic-discoid, up to 12 mm long, 6 mm wide. Bracts slightly puberulent, completely connate into a oblong involucre, the involucre up to 16 mm long, 6 mm wide. Male flowers obovoid, ca. 1.8 mm long, 1.5 mm wide, pedicellate, subtended by bracteoles; bracteoles cymbiform, up to 3.6 mm long, 1.8 mm wide when blooming, the apex truncate and ciliolate, the margins ciliolate at upper parts, the abaxial vein puberulent; sepals 5, glabrous, valvate, elliptic-cymbiform, the largest one ca. 2 mm long, 0.9 mm wide, corniculate at subapex, the smallest one ca. 1.7 mm long, 0.7 mm wide, nearely entire, slightly corniculate. Female flowers pedicellate, subtended by bracteoles; bracteoles semi-transparent, lanceolate, ca. 1.8 mm long, 0.3 mm wide when blooming, the upper margins and apex ciliate, the abaxial side nearly glabrous; sepals 5, rudimentary, less than 0.2 mm long; staminodes 5, minute, enlarged when fruiting; stigma formed with septate hairs, penicillate, 1.5 to 5 times as long as ovary; ovary glabrous, oblong, ca. 0.4 mm long, 0.26 mm wide. Achenes with obscurely 6 ribs from apex faded toward base, oblong, ca. 0.9 mm long, 0.43 mm wide, densely brown-spotted.

Additional specimens examined. TAITUNG HSIEN: Lanyu, Shih 3163, 3166, 3174, 3193 (NSYSU); Chang 17800, 19595, 19781 (PPI). HUALIEN HSIEN: Chimay, Shih 3094 (NSYSU).

Distribution. Endemic; found in Island Lanyu and Hualien County at low altitude, growing along ravines and on moist forest floors. Flowering from July to October.

Note. This is a distinct species of uncertain affinities, although it superficially resembles to Elatostema edule C. Robinson. The former has stems dark-green and terete or subterete, male inflorescences 1.8 cm in diameter and plants without mint-like odor, whereas the latter has stems greenish and angular, male inflorescences 3 cm in diameter and plants with mint-like odor.

14. Elatostema trilobulatum (Hayata) Yamazaki, J. Jap. Bot. 47(6): 180, f. 1. 1972. Figure 9

Pellionia trilobulata Hayata, J. Coll. Sci. Imp. Univ. Tokyo 30(1): 280; Icon. Pl. Formosan. 6: 56. 1916; Liu & Huang, Li et al., Fl. Taiwan 2: 205. 1976; Ying, Coloured Ill. Fl. Taiwan 3: 452, photo 552, 1988.

Elatostema obtusum Wedd. var. trilobulatum (Hayata) Wang, Bull. Bot. Lab. N.E. Forest. Inst., Harbin. 4(7): 66. 1980.

Elatostema obtusum auct. non Wedd.: Ying, Coloured Ill. Fl. Taiwan 3: 459, photo 558. 1988, excl. syn.

Perennial herbs; stems slender, subterete, canaliculate at upper side when living, with retrose hairs along the two

edges of the furrow, with many brown 4-celled scales, usually creeping or ascending, rooting at nodes, branched, greenish, up to 50 cm long, 2 mm thick. Leaves alternate, sessile or subsessile, stipulate, distichous; lamina membranaceous to herbaceous, sparsely hirsute and with dense up to 0.5 mm long linear cystoliths on adaxial side, glabrous and without cystolith on abaxial side, greenish on adaxial side, pale-green on abaxial side, asymmetrically oblong or obovate, 0.9_1.8 cm long, 0.35_1.2 cm wide, the base of the distal half semi-cordate, the margins slightly minute-ciliolate, with 2_3 serrate teeth at the distal half and 1_2 teeth at the proximal half, the apex acute, obtuse or rounded, the triplinerves articulated with lateral and secondary nerves; stipules 2, unequal, opposite, persistent, 1-nerved, glabrous, greenish, the one of normal leaves triangular, ca. 0.5 mm long, 0.18 mm wide, the other linear-triangular to narrowly triangular, ca. 2 mm long, 0.3 mm wide. Male inflorescences usually of (1_)5_6-flowered glomerules, sometimes of more than 25-flowered cymose glomerules; bracts 2, incompletely connate into an involucre, sparsely hirsute and puberulent outside, cymbiform, ca. 2.3 mm long, 1.7 mm wide, keeled, corniculate; peduncles up to 1.3 cm long. Female inflorescences sessile or subsessile, usually 1-flowered; bracts 2, hirsute, ciliate, connate at base, cymbiform, up to 3.3 mm long, 2 mm wide. Male flowers slightly lateral-compressed, obovoid, up to 2.5 mm long, 3 mm wide; sepals 4, connate halfway, unequal, sparsely puberulent and ciliate, cymbiform, up to 2.5 mm long, 2.4 mm wide, corniculate; pedicels ca. 1.3 mm long. Female flowers with 6-7 rudimentary sepals; staminodes 6 or 7, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ovoid, ca. 0.3 mm long, 0.2 mm wide. Achenes glabrous, inconspicously 4-ribbed at subapex toward apex, ovoid, ca. 1.7 mm long, 0.9 mm wide.

Specimens examined. ILAN HSIEN: Taipingshan, Huang 4776, 4969 (TAI). TAOYUAN HSIEN: Rarashan, Shih 3109 (NSYSU). HSINCHU HSIEN: Kuanwu, Huang 6671 (TAI). TAICHUNG HSIEN: Hohuan Chanel, Shih 3249 (NSYSU). NANTOU HSIEN: Randaishan, 1908, Kawakami & Mori s. n. (TAIF); Kawakami, 1908, Hayata & Mori s. n. (TAIF); Yushan (en route), Huang et al. 14271 (TAI); Chang 18088 (PPI). CHIAYI HSIEN: Alishan, 1914, Ito s. n. (TAIF); Kuoh 7445 (TAI). PINGTUNG HSIEN: Tawushan, Yang 23454 (PPI). TAITUNG HSIEN: Chipentsushan, Shih 2670, 2679 (NSYSU). HUALIEN HSIEN: Hohuanshan, Shih 2893, 2918, 3246 (NSYSU); Kiraikei-Asahi, Matuda 269 (TAIF).

Distribution. Endemic. Distributed at medium and high altitudes throughout the Central Ridge, mostly growing on moist floors and ravines.

Note. This species is very similar to Elatostema obtusum Wedd. However, E. trilobulatum always has semiterete stems and hairs confined to the two ridges of the concave sides of the canaliculate stems whereas E. obtusum usually has quadri-angular stems and hairs throughout the stems. In addition, the male inflorescences of E.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

Figure 9. Elatostema trilobulatum (Hayata) Yamazaki, from Shih 2670. A, Habit. B, Portion of stem (enlarged). C, Leaves (abaxial view). D, Male inflorescence in blooming. E, Male flower. F, Male sepals (ventral view). G, Male bracteole (abaxial view). H, Achene.

Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan

trilobulatum usually have 5-6 flowers, whereas those of the latter have 1_3 flowers.

15. Elatostema villosum Shih & Yang, sp. nov. Figure 10

Species nova affinis Elatostemati strigillosi Shih & Yang, sed caulibus dense villosis nec breve strigillosis, foliis magnis obovato-oblanceolatis nec parvis obovatis.—TYPE: Taiwan. Taitung Hsien: Lanyu, Shih 2808 (holotype: NSYSU; isotypes: HAST, TAI, TAIF)

Perennial herbs; stems aggregated, ascending or suspending from the substrate it growing, usually rooting at nodes of lower parts, branched, densely villous throughout, dark brownish-green, up to 45 cm long, 3 mm thick. Leaves alternate, sessile or subsessile, distichous; lamina chartaceous, densely villous, with very dense, 0.2_0.3 mm long cystoliths on upper surface, deep green to green on adaxial side, pale green on abaxial side, asymmetrically obovate-oblanceolate, 2_5(_5.5) cm long, 7_20(_22) mm wide, the base of the distal half semi-

Figure 10. Elatostema villosum Shih & Yang, from Shih 2808. A, Habit. B, Leaf (abaxial view). C, Portion of leaf margin. D, Stipules, left: abaxial view, right: sublateral view. E, Stipule (abaxial view). F, Female inflorescence (ventral view). G, Achene with staminodes & bracteole. H, Staminodes, rudimentary sepals & pedicel.

Botanical Bulletin of Academia Sinica, Vol. 36, 1995

cordate, the margins ciliate and serrate, the apex cuspidate ciliate, the nerves prominent beneath, the secondary veins 4_6 of distal half and 3_5 of the proximal half; stipules 2, opposite, persistent, ciliate, glabrous on adaxial sides, hirsute on abaxial sides, greenish at nascent parts and brownish at older parts, narrowly triangular, 3_5.5 mm long. Female inflorescences sessile or subsessile, greenish, turning into brownish with deep brown dots when fruiting, densely puberulent outside, subquadrate, up to 4.5 mm in length and wideth; bracts densely puberulent, incompletely connate into a subquadrate involucre, up to 3 mm long and wide. Female flowers subtended by bracteoles, pedicellate; bracteoles semi-transparent, narrowly lanceolate, ca. 0.6 mm long, 0.2 mm wide when blooming, the margins ciliolate, the abaxial sides puberulent; sepals rudimentary; staminodes 3 or 4, minute, enlarged when fruiting; stigma penicillate; ovary glabrous, ovoid. Achenes ovoid, ca. 0.6 mm long, 0.3 mm wide, with ca. 12 winglike ribs.

Specimens examined. CHIAYI HSIEN: Ta-pu Hsiang, The Third Highway (at the entrance of Cheng-wen Reservoir), Shih 2723 (NSYSU); Tsuchi Hsiang, Kuanyin Fall Forest Recreation Area, Leu 1625 (HAST). KAOHSIUNG HSIEN: Shanming Bridge, Shih 3334, 3406 (NSYSU).

Distribution. Endemic. Distributed in the southern parts of this island, at low to medium altitudes. Mostly growing along ravines, sometimes in moist forest floors.

Note: The new species shows a resemblance in habit, plant size and propagation to Elatostema strigillosum Shih & Yang. However, the former has villous hairs on plants and twelve winglike ribs on achenes, the latter has strigillose hairs on plants and eight ribs on achenes.

Acknowledgments. This research was partly supported by the Council of Agriculture, Executive Yuan, R. O. C. We are indebted to Dr. C. M. Wilmot-Dear for critical review of the manuscript and valuable suggestions. We thank W. T. Wang and C. J. Chen for literature and information. We are grateful to Dr.

C.-I Peng for painstakingly improving the manuscript. Special thanks are given to the directors of HAST, PPI (Herbarium, National Pingtung Polytechnic Institute, Pingtung, Taiwan), TAI, TAIF, and NTNU for access to specimens. We are grateful to Yu-fin Lee for the excellent line-drawings.

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Yang et al. — A revision of Elatostema (Urticaceae) of Taiwan