Bot. Bull. Acad. Sin. (1997) 38: 285-295

Notes on Limnophila (Scrophulariaceae) of Taiwan

Yuen-Po Yang¹ and Shen-Horn Yen

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

(Received November 20, 1996; Accepted May 27, 1997)

Abstract. Four species of the genus Limnophila (Scrophulariaceae) of Taiwan are studied; two new species, Limnophila aromaticoides Yang & Yen and L. taoyuanensis Yang & Yen are described; L. heterophylla (Roxb.) Benth. is confirmed; L. sessiliflora (Vahl) Bl. is supplemented with diagnosis. Their descriptions are given, and the line drawings are provided in this paper.

Keywords: Limnophila; Species; Taiwan.

Introduction

In the course of studying Limnophila of Taiwan, two new species have been found. A species of uncertain status since 1987 is confirmed. In addition, a species is supplemented with diagnosis. The key to the species in Taiwan and their descriptions are given as follows.

Key to the Species of Limnophila in Taiwan

1. Plants with simple to lacerate leaves.

2. Leaves petiolate L. rugosa

2. Leaves sessile or subsessile.

3. Flowers sessile L. heterophylla

3. Flowers pedicellate.

4. Submerged leaves rarely present, opposite to 3-verticillate; corolla pink; fruit ellipsoid L. aromatica

4. Submerged leaves always present, (2-)3-8(-10)-verticillate; corolla white or rarely pinkish at top of corolla tube; fruit orbicular L. aromaticoides

1. Plants with finely divided leaves wholly or partly.

5. Segments of divided leaves capillary; cleistogamous flowers absent L. taoyuanensis

5. Segments of divided leaves flattened; cleistogamous flowers present.

6. Calyx glabrous or glandular.

7. Capsule globular, sessile; aerial flowers with corolla tube more than 5 mm long L. heterophylla

7. Capsule ellipsoid, stipitate; aerial flowers with corolla less than 3 mm long L. trichophylla*

6. Calyx sparsely hirsute L. sessiliflora

*This species will be discussed in the near future. The diagnostic characters used in the key tentatively follow Li's description in 1978.

1. Limnophila aromaticoides Yang & Yen, sp. nov. (Figures 1, 2, 6A, 7A-D)

Herba aquatica. Caules crassi, usque 30 cm longi, superne erecti, glabri vel minute glanduliferi, inferne glabri. Folia superne opposita vel 3_5-verticillata, anguste lanceolata, serrato-dentata, sessilia, subamlexicaulia, inferne 3_8-verticillata, oblongo-lanceolata vel lineari-lanceolata. Flores solitarii vel in racemos terminales et axillares, pedicellis 1_15 mm longis. Calyx 5_6.5 mm longus, minute glandulifer, lobis lineari-lanceo-latis, 2.5_4.0 mm longis, acuminatis. Corolla 5_10 mm longa, extus glabra, intus villosa, pallide caerulea. Capsula 5 mm longa, compressi-globosa.—TYPE: Monghu, Hsichih, Taipei Co., Yen s. n. in 1994 (holotype: TAIF; isotypes: TAI, HAST).

Herbaceous aquatic plants. Stems erect above, simple to branched, 10_30 cm tall, glabrous to minutely glandular. Emerged leaves mostly opposite, rarely 3_5-verticillate, chartaceous, elliptic to oblong-lanceolate, 5_35 mm long, 4_10 mm wide, acute or obtuse at apex, attenuate at base, sessile, occasionally semi-amplexicaul, crenate-serrate, glabrous to sub-glandular on veins beneath, punctate, pinnate-veined; submerged leaves (2)3-8(10)-verticillate, membranous, oblong-lanceolate or linear-lanceolate, 10_40 mm long, 3_10 mm wide, acute at apex, serrate-dentate, sessile, semi-amplexicaul, glabrous. Bracts lanceolate to oblong-lanceolate, 3_10 mm long, 2_3 mm wide; bracteoles 2, oblong-lanceolate, 0.8_2.0 mm long, ca. 0.8 mm wide, somewhat ciliate, obtuse at apex. Flowers solitary in axils or in racemes; pedicellate, rarely sessile to subsessile, pedicels slender, 1_15 mm long, glabrous to densely fine-glandular, calyx 5_6.5 mm long, 2_3 mm wide, patently glandular, striate at maturity, lobes narrowly lanceolate, 2.5_4.0 mm long, ca. 1.5 mm wide, as long as or slightly longer than

¹Corresponding author. Fax: (07) 525-3609; E-mail: Zygamann.bbs@bbs2.nsysu.edu.tw

Botanical Bulletin of Academia Sinica, Vol. 38, 1997

Figure 1. Limnophila aromaticoides Yang & Yen. A, Habit with emerged leaves; B, Habit with submerged leaves; C, Corolla; D, Calyx and pistil; E, Stamens; F, Capsule; G, Seed. Scale bar = 1 cm.

Yang and Yen — Limnophila of Taiwan

the mature capsule, acuminate, sub-reflexed at maturity; corolla white or rarely pinkish at top of tube, 5_10 mm long, finely and sparsely glandular, upper lip orbicular, emarginate, lower lip 3-lobed, lobes orbicular; stamens didynamous, posterior filaments 1_1.5 mm long, villous, anterior filaments 3.0_4.0 mm long, glabrous. Capsules compressed orbicularly ellipsoid, 5 mm long, 4 mm wide, green to brown. Flowering Apr-Nov.

Distribution. In Taiwan, found mainly in the northern (Keelung River Basin and Neishuanghsih Basin) and northeastern parts (Tungshan River Basin) (Figures 7A_D). A small colony found in Kaohsiung in southern Taiwan (Figure 6A). Mostly growing in ponds, rice fields or ditches. This species is possibly also distributed in Japan because several specimens of the area at TAI are very similar to it.

Additional specimens examined. TAIPEI CITY: Taipei, Simada 885c (TAI), Masamune s. n. (TAI), Sasaki s. n. (TAI), Chuang 3048 (TAI); Shihting, Yen s. n. in 1991 (NSYSU); Nankang, Yen s. n. in 1989 (NSYSU); Neihu, Yen s. n. in 1991 (NSYSU); Wanlee, Yen s. n. in 1995 (NSYSU); Neishuanghsih, Yen s. n. in 1994 (NSYSU); Hsichih, Peng 13530 (HAST); Peng 13552 (HAST); Yangmingshan, Chen & Liu 19 (HAST);. KEELUNG HSIEN: Badu, Yen s. n. in 1992 (NSYSU). TAOYUAN HSIEN: Taoyuan, Suzuki 5825 (TAI), Sasaki s. n. (TAI), Huang 3525 (TAI), Suzuki ST20574 (TAI); Lungtan, Yen s. n. in 1988 (NSYSU); Yen s. n. in 1988 (HAST); Yangmei, Yen s. n. in 1988 (NSYSU); Pa-tei, Huang 4606 (HAST); Chuang 4620 (HAST). ILAN HSIEN: Tungshan, Tungshan, Yen s. n. in 1991 (NSYSU). KAOHSIUNG HSIEN: Fengshan, Yen s. n. in 1992 (NSYSU).

Note. The species is very similar to Limnophila aromatica (Lam.) Merr. In Taiwan, collections of the species were previously misidentified as it. However, the new species can be distinguished by its verticillate submerged leaves, white corolla, which is occasionally pinkish at top, and orbicularly ellipsoid capsule. In comparison, L. aromatica can be diagnosed by the character combination of submerged leaves mostly lacking corolla (occasionally with 2_3 submerged leaves), corolla pink or purple and capsule ellipsoidal.

2. Limnophila taoyuanensis Yang & Yen, sp. nov. (Figures 2, 3, 6B & C, 7A, 7C)

Herba aquatica. Caules usque ad 10 cm longi, basi glabri, superne erecti, sub-pilosi ad glabri. Folia verticillata, 2_3-fidis vel lobatis, glabra, laciniis linearibus ad filiformibus, 0.3_0.5 mm latis, apice acuta. Flores axillares, solitarii, pedicellis 2.5 mm longis. Calyx 3.5_5.5 mm longus, extus glabra, apice 5-lobatus, lobis lanceolato-ovatus, 2_3.5 mm longis, apice breviter acutis. Corolla extus glabra, limbo 2-labiato, labio superiore orbiculato. Stamina 4, filamentis glabri.—TYPE: Pachangli, Lungtan, Taoyuan, Yen s. n. in 1987 (holotype: TAIF; isotype: TAI, HAST).

Aquatic plants. Emerged stems erect, branched, 1_1.5 mm in diameter, slightly pilose to glabrous, violet; submerged stems branched, 1_1.2 mm in diameter, green. Emerged leaves 5_6-verticillate, deeply dissected, segments obtuse to rounded at apex, the leaves at blooming entire, elliptic to lanceolate; submerged leaves mostly 6_8-verticillate, finely divided, 5_25 mm long, segments opposite, filiform to capillary, 0.2_0.4 mm wide, obtuse to rounded at apex. Bracteoles usually absent. Aerial flowers solitary, axillary, sessile or subsessile; calyx 3.5_5.5 mm long, glabrous outside, lobes lanceolate-ovate, 2_3.5 mm long, short, acuminate, glabrous outside; corolla-tube white at top and yellow at base, 8_11 mm long, glabrous outside, villous inside laterally, upper lip white or light pink with two pink dots, orbicular, emarginate, lower lip white, 3-lobed, lobes broadly ovate; stamens usually with anthers contiguous, posterior filaments about 1 mm long, glabrous; style 1.5_3 mm long; cleistogamous absent. Capsule unknown. Flowering May-Oct.

Distribution. Endemic. Previously several small colonies found in northern and southern Taiwan, but now nearly extinct in the field because of destruction of habitats (Figures 7A & C). Currently, only a few plants cultivated at Fushan Botanical Garden in Ilan.

Additional specimens examined. TAOYUAN HSIEN: Lung-tan, Kao 10743 (TAI); Pachangli, Peng 11132 (HAST); Pa-tei, Chuang 4607 (HAST). NANTOU HSIEN: Chu-shan, Huang 5669 (TAI). CHIAYI HSIEN: Da-pu, Yen s. n. in 1992 (NSYSU).

Note. This species is close to Limnophila stipitata (Hayata) Makino & Nemoto, but differs from it by having deeply dissected emergent leaves at the sterile stage and at anthesis producing entire emergent leaves, and finely divided submerged leaves with only filiform to capillary segments and sessile to sub-sessile flowers. On the other hand, L. stipitata has slightly dissected emergent leaves at the sterile stage and at anthesis producing crenate-serrate to variously lacerate emergent leaves, and finely divided submerged leaves with flattened segments, and flowers with 0_15 mm long pedicels.

3. Limnophila heterophylla (Roxb.) Benth., Scroph. Ind. 25. 1835; Philcox in Kew Bull. 24(1): 124. 1970; Yamazaki in Journ. Fac. Sci. Univ. Tokyo III 13: 586. 1985. (Figures 5, 6D, 7A, 7E)

Columnea heterophylla Roxb., Fl. Ind. ed. Carey, 3: 97. 1832.

Aquatic plants. Emerged stems up to 20 cm tall, 2_3 mm in diameter, branched, glabrous; submerged stems branched, stipitate, glandular to subglabrous, 3_3.5 mm in diameter. Emerged leaves verticillate below, opposite to alternate above, oblong, 5_16 mm long, 2_4 mm wide, sessile, semi-amplexicaul, serrulate, glabrous; submerged leaves 6_10-verticillate, finely divided, segments opposite, flattened, 0.8_1.0 mm wide, obtuse to rounded at apex. Bracteoles usually absent. Aerial flowers axillary, solitary or in terminal spikes; calyx campanulate, 3_4 mm long,

Botanical Bulletin of Academia Sinica, Vol. 38, 1997

Figure 2. Limnophila taoyuanensis Yang & Yen. A, Habit with emerged stems and leaves; B, Emerged leaf; C, Stem and glandular hairs; D, Flower and a hair of corolla; E, Corolla and hairs inside; F, Calyx and pistil; G, Stamens; H, Sections of ovary. Scale bar = 1 cm.

minutely glandular, lobes broadly ovate, half as long as the calyx-tube; corolla 5_6 mm long, violet, glabrous outside, villous inside laterally, upper lip circular, emarginate, lower lip 3-lobed, lobes broadly ovate; stamens usually with anthers contiguous, filaments glabrous, posterior ones ca. 1 mm long, anterior ones ca. 3 mm long; style ca. 3 mm long; cleistogamous flowers sessile; corolla smaller; calyx minutely glandular to glabrous. Capsules compressed globular, ca. 2.5 mm long and across. Flowering May-Oct.

Distribution. Widely distributed throughout eastern Asia. In Taiwan, found only at a small pond and very endangered (Figures 7A, 7E), but now nearly extinct in

the field because of habitat destruction. Currently, only a few plants cultivated in the laboratory of the authors.

Specimens examined. KAOHSIUNG HSIEN: Meinung, Chung-cheng Lake, Yen s. n. in 1995 (NSYSU). PINGTUNG HSIEN: Bankinsing, Henry 1849 (NY).

Note. Philcox (1970) included Taiwan in the range of distribution of L. heterophylla based on Henry 1849 (K). Probably neglected by Li, the species was not included in the flora of Taiwan in 1978. Because no specimens of this species were available in the Taiwan herbaria, it was treated as an uncertain species by Yang (1987). In 1991, the first author examined a sheet of Henry's collection at NY and agreed with Philcox's opinion. In addition, Yen

Yang and Yen — Limnophila of Taiwan

Figure 3. Limnophila taoyuanensis Yang & Yen. A, Habit with emerged and submerged leaves; B, Leaf and flower; C, Corolla; D, Calyx and pistil; E, Stamens; F, Glandular hiars. Scale bar = 1 cm.

Botanical Bulletin of Academia Sinica, Vol. 38, 1997

Figure 4. Limnophila sessiliflora Bl. A, Habit; B, Flower; C, Corolla; D, Capsule with bracteoles on submerged stem; E, Capsule without bracteoles on emerged stem; F, Submerged leaf; G, Emerged leaves. Scale bar = 1 cm.

Yang and Yen — Limnophila of Taiwan

Figure 5. Limnophila heterophylla (Roxb.) Benth. A, Habit; B, Submerged leaves; C, Emerged leaf; D, Flower; E, Corolla; F, Calyx and pistil; G, Stamens; H, Sections of ovary. Scale bar = 1 cm.

Botanical Bulletin of Academia Sinica, Vol. 38, 1997

made a collection of this species from a pond near Chung-cheng Lake, Meinung, Kaohsiung, in 1995. This species is therefore confirmed for Taiwan.

4. Limnophila sessiliflora (Vahl) Bl., Bijdr. 749. 1826; Philcox in Kew Bull. 24(1): 112. 1970; Yamazaki in Journ. Fac. Sci. Univ. Tokyo III 13: 579. 1985.

(Figures 4, 6E, 7A, 7D)

Hottonia sessiflora Vahl, Symb. Bot. 2: 36. 1791.

Aquatic plants. Emerged stems 2_3 mm in diameter, branched, pubescent to somewhat glabrous, green to pink; submerged stems branched, sparsely pubescent to somewhat glabrous, green to reddish. Emerged leaves 5_8-verticillate, elliptic to lanceolate, 10_20 mm long, slightly dissected on sterile stems, crenate-serrate to variously lacerate on flowering stems, segments obtuse to rounded at apex, dark green; submerged leaves 6_10(-more)-verticillate, rhomboid, ovate, elliptic to broadly lanceolate, 5_40 mm long, segments opposite, flattened, 0.8_1.0 mm

A

B

C

D

E

F

Figure 6. Habit of Limnophila species. A, Limnophila aromaticoides Yang & Yen, flowering; B, Limnophila taoyuanensis Yang & Yen, flowering; C, Limnophila taoyuanensis Yang & Yen, emerged plants; D, Limnophila heterophylla (Roxb.) Benth., flowering; E, Limnophila sessiliflora (Vahl) Bl., native colony in Ilan Hsien; F, Limnophila sessiliflora (Vahl) Bl. from S.E. Asia, naturalized colony in Chang-Hua Hsien.

Yang and Yen — Limnophila of Taiwan

Figure 7. Distribution map of some Limnophila species in Taiwan. A, General distribution of each species on the island; B, Distribution in Taipei Hsien; C, Distribution in Taoyuan and Hsinchu; D, Distribution in Ilan Hsien; E, Distribution in Kaohsiung and Pingtung. L. aromaticoides (solid triangles), L. taoyuanensis (solid squares), L. heterophylla (solid circles), L. sessiliflora (empty squares). Scale bar = 1 km.

Botanical Bulletin of Academia Sinica, Vol. 38, 1997

wide, rounded to obtuse at apex. Bracteoles usually absent. Aerial flowers solitary, axillary, sessile or subsessile; calyx 4_7 mm long, densely to sparsely pubescent, not striate at maturity, lobes ovate, 2_3.5 mm long, acuminate; corolla 5_8 mm long, blue, violet to purple, glabrous outside, villous inside laterally, upper lip white or light pink with 2 blue dots, orbicular, emarginate, lower lip white, 3-lobed, lobes broadly ovate; stamens usually with anthers contiguous, filaments glabrous, posterior ones about 1 mm long, anterior ones about 3 mm long; style about 3 mm long; cleistogamous flowers sessile, rarely subsessile after fruiting; corolla smaller and reduced; calyx sparsely pubescent to glabrous; bracteoles linear, rarely present. Capsules compressed ellipsoid, 3.5_5.5 mm long, pale green-brown when submerged, dark brown when emerged. Flowering Apr-Nov.

Distribution. Widely distributed in eastern Asia; found only at a few localities in the northern and northeastern parts of Taiwan (Figures 7A, 7D), at low altitudes. Mostly growing along ditches or in ponds.

Specimens examined. TAIPEI HSIEN: Tang-shui, Yen s. n. in 1993 (NSYSU); ILAN HSIEN: Su-ao, Shimada s. n. in 1932 (TAI), Yang s. n. in 1976 (TAIF); Tungshan, Yen s. n. in 1994 (NSYSU).

Note. In 1906, Matsumura and Hayata listed Limnophila sessiliflora for Taiwan based on Henry's collections from Bankinsing. However, Li (1978) assumed that they misidentified the specimens and excluded the species from the flora of Taiwan. In fact, the misidentification was implied in the Philcox' worldwide revision of Limnophila as early as 1970. He examined all Henry's specimens of the genus collected from the location and did not indicate any of them belonging to the species.

As to the real L. sessiliflora, a collection of its flowering materials with submerged leaves was made by Shimada at Su-ao, Ilan, in 1932. The specimen was distributed as L. indica (L.) Druce and filed under L. trichophylla (Komarov) Komarov at TAI. In 1976, a specimen of L. sessiliflora from Su-ao, I-lan Hsien, was collected by the first author, but was neglected until the

authors re-examined it in 1986. The species was listed in the aquatic flora of the island by Yang (1987), but was not described. Since then, the second author has confirmed several distributional locations of the species in the northern and northeastern parts of Taiwan.

The species is often described as having no bracteoles below the calyces by some authors such as Philcox (1970) and Yamazaki (1985). However, in Taiwanese materials, the present authors found that the majority of submerged cleistogamous flowers bore two identical bracteoles and even produced very short pedicels.

Several naturalized colonies of Limnophila sessiliflora, which were introduced from S.E. Asia, are found in Chang-hua Hsien of central Taiwan (Yen, s. n., in 1988, NSYSU). The plants of the naturalized colonies could be distinguished from the native ones by their larger size, paler corolla, and infertile capsule (Figure 5F).

Acknowledgements. We are indebted to Drs. T. Yamazaki (Tokyo), D. Boufford (Harvard University), D. Philcox and C.I. Peng (Academia Sinica) for providing scientific suggestions. We also thank Y.M. Chou and C.Y. Wang for the line drawings of plants; A.S. Huang, W.H. Chang, F.G. Chen, Y.C. Chuan and Y.S. Lee for their assistance in collecting aquatic plants in the field during the past ten years.

Literature Cited

Li, H. L. 1978. Scrophulariaceae. In H. L. Li, T. S. Liu, T. C. Huang, T. Koyama, and C. E. DeVol (eds.), Flora of Taiwan, vol. IV. Epoch Publishing Co., Ltd., Taiwan, pp. 551_616.

Matsumura, J. and B. Hayata. 1906. Enumeratio Plantarum Formosanarum. Journ. Coll. Sci., Imp. Uni. Tokyo, Japan 22: 277.

Philcox, D. 1970. A taxonomic revision of the genus Limnophila R. Br. (Scrophulariaceae). Kew Bull. 24(1): 101_170.

Yamazaki, T. 1985. A revision of the genera Limnophila and Torenia from Indochina. Journ. Fac. Sci. Univ. Tokyo. III 13: 575_624.

Yang, Y. P. 1987. A synopsis of aquatic angiospermous plants of Taiwan. Bot. Bull. Acad. Sin. 28: 191_209.

Yang and Yen — Limnophila of Taiwan

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