Botanical Studies (2009) 50: 229-240.

*

Corresponding author: E-mail: biofv017@ntnu.edu.tw; Tel:

886-2-29326234 ext. 229; Fax: 886-2-29312904.

INTRODUCTION

Asarum L., s.l., (Aristolochiaceae), contains about 90

species distributed in the north temperate zone, with the

center of diversity in eastern Asia (Huang et al., 2003).

Asarum is often split into several genera; Heterotropa

Morren & Decne., Hexastylis Raf., Asiasarum Maekawa,

Japonasarum Nakai, and Geotaenium Maekawa. The

study by Kelly (1998) supported recognition of two

subgenera, Asarum and Heterotropa, and that treatment is

adopted here (1998).

Most species of Asarum are low-growing, rhizomatous

herbs in shaded, moist, broadleaved forests. The floral

characteristics are diverse, but the extremely conservative

gross morphology of the species has resulted in confusion.

Floral characters are difficult to determine in dried

specimens. Since Hayata¡¦s (1915) pioneering work, the

treatments of Asarum in Taiwan have been incongruous,

with from 5 to 13 species being recognized (Lai, 1973;

Wu et al., 1974; Liu and Lai, 1976; Maekawa, 1978;

Cheng and Yang, 1983, 1988; Huang et al., 1995; Huang,

1996; Lu, 2001; Huang et al., 2003). Recently, Huang

et al. (1995) critically revised Asarum on the bases

Three new species of Asarum (section Heterotropa) from

Taiwan

Chang-Tse LU and Jenn-Che WANG*

Department of Life Science, National Taiwan Normal University, 88, Ting-Chow Rd., Sec 4, Wenshan, Taipei 11677,

Taiwan

(Received July 18, 2008; Accepted November 27, 2008)

ABSTRACT.

Three new species of Asarum L. sect. Heterotropa: A. chatienshanianum C . T. Lu & J.

C. Wang, A. tawushanianum C. T. Lu & J. C. Wang, and A. villisepalum C. T. Lu & J. C. Wang, from

Taiwan are described and illustrated. The somatic chromosome number and micromorphology of pollen

grains of all of them were also examined. The somatic chromosome number in all three species is 2n=24.

The tectum of the pollen is rugulate-perforate with large supratectate warts in A. tawushanianum and A.

villisepalum but composed of perforated subunits in A. chateinshanianum. Asarum chatienshanianum and

A. villisepalum are similar to A. macranthum Hook f. in gross morphology, but differ in floral morphology.

Asarum chatienshanianum has greenish yellow flowers, a longer cylindrical calyx tube and the apex of the

styles is bilobed. Asarum villisepalum is distinguished by dark maroon flowers, the densely white villous

adaxial surface of the calyx lobes, and the internal surface of the calyx tube with 12 and 24 longitudinal

ridges on the upper and lower part respectively. Asarum tawushanianum resembles A. hypogynum Hayata,

but is distinguishable in having a short cylindrical calyx tube and smaller dark purple flowers. Descriptions,

illustration and a synoptic key are provided for comparison with other species of Asarum in Taiwan.

Keywords: Asarum; Aristolochiaceae; Chromosome number; Heterotropa; Pollen; Taiwan.

of morphology, pollen features, and karyotype. They

recognized six species, including two new species, A.

crassusepalum S. F. Huang, T. H. Hsieh & T. C. Huang

and A. taipingshanianum S. F. Huang, T. H. Hsieh & T.

C. Huang. They (Huang et al., 1995) treated several of

Hayata¡¦s species as synonyms of the very variable A.

macranthum Hook. f. within which three morphologically

distinguishable populations have been described. Most

recently, Asarum of Taiwan was revised again (Lu, 2001)

based on comparative morphology, palynology, cytology

and molecular evidence to elucidate the taxonomy and

phylogeny of the genus. The present paper describes three

new species that were overlooked or were previously

misidentified as A. macranthum. The morphological terms

used in this paper follow Sugawara (1987) and Huang et

al. (1995).

MATERIALS AND METHODS

Materials used in this study were collected from the

field throughout Taiwan. Living material was cultivated

in the greenhouse, Department of Life Sciences,

National Taiwan Normal University. Most plants were

pressed and dried and the specimens are deposited in

the TNU Herbarium. Voucher specimens for pollen and

chromosome observations are also preserved at TNU.

SySTEMATICS

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Botanical Studies, Vol. 50, 2009

Pollen grains for scanning electron microscopic (SEM)

study were collected from fresh anthers and prepared by

the method proposed by Erdtman (1952). The acetolyzed

grains were dehydrated through an ethanol series, critical

point dried, coated with gold, and examined with a Hitachi

SM 2400 scanning electron microscope (SEM).

Root tips for cytological study were pretreated with

0.1% colchicines for 3-4 hours at room temperature and

fixed in a 3:1 mixture of 99.5% ethyl alcohol and acetic

acid for 1 day. After maceration with 5% pectinase, the

root tips were squashed in an acetic orcein solution.

NEW SPECIES

1. Asarum chatienshanianum C. T. Lu & J. C. Wang,

sp. nov.¡XTYPE: Taipei County: Sanhsia Town, Mt.

Peichatienshan, en route from entrance to shelter, elev.

ca. 600-950 m, C. T. Lu 571 (holotype: TNU; isotype:

TNU). bZ

(Figures 1, 4A-D)

Diagnosis. Affine A. macrantho, sed calycis tubo

longius anguste cylindricus, extus dilute purpureo-

virescente, intus purpureus, irregularis tessellatus, calycis

lobis flavo-virescentibus, non valde undulatis, stylis apice

bilobis et stigmatibus extrorsus, differt.

Herbs, perennial. Plants forming clumps. Adventitious

roots few, glabrous. Rhizomes glabrous, repent, clustered

at nodes. Leaves long petiolate; petiole ca. 10-30 cm long,

adaxially hairy, grooved, purple; blade triangular-oblong

to triangular-ovate, 8-16 cm long, 6-10 cm wide, base

cordate and 2 lobed, lobes 2-3.5 cm long, 3-5 cm wide,

apex acute; upper surface usually dark green, glabrous,

with white blotches, lower surface pale green; young

leaves adaxially and on margin usually with short hairs.

Flowering branch with 2 or 3 cataphylls at base, cataphylls

ca. 2 cm long, ovate, both surfaces glabrous, margin hairy.

Flowers solitary, yellowish green, axillary, decumbent on

ground; pedicel glabrous, 1-1.5 cm long; calyx tube ca.

12-15 mm long, basally ca. 7 mm wide, apically ca. 7-8.5

mm wide, glabrous outside, irregularly tessellated inside,

longitudinal ridges 12-15; lobes 3, shorter than calyx tube;

calyx tube opening 3-5 mm in diam.; orifice ring ca. 5-10

mm wide; calyx lobes spreading obliquely, triangular to

ovate, 10 mm long, 10 mm wide, abaxially glabrous, with

short hairs adaxially; lamellate appendage present between

orifice and calyx lobes; stamens 12, in 2 whorls, 2-2.5 mm

long, filament short, anthers extrorse, 1.2-1.5 mm long,

apex of connectives rounded; ovary superior, locules 6,

fused; styles 6, free; styles half as long as calyx tube, apex

of stylar protuberance 2 lobed; stigma elliptic, extrorse;

ovules 8-10 per locule. Somatic chromosome number 2n =

24 (Figure 6A).

Additional specimens examined. TAIPEI COUNTY.

Sanhsia Town: Mt. Peichatienshan, en route from

entrance to shelter, elev. ca. 600-950 m, C.C. Liao et al.

354 (HAST), elev. ca. 950-1,150 m, C.C. Liao et al. 369

(HAST), C.T. Lu 150 (TNU), 570 (TNU), 571 (TNU),

572 (TNU), Mt. Peicha, elev. ca. 1,200-1,400 m, L.W.

Wu 6 (TNU); Wulai Township: Neitung logged trail, C.T.

Lu 1068 (TNU). ILAN COUNTY. Chiaohsi Township:

Shengmushanchung National Forest trail, en route from

Bridge Tungtienchiao to Shengmu Lodge, elev. ca.

400-900 m, C.T. Lu 868 (TNU).

Distribution and habitat. Endemic to Taiwan.

Asarum chatienshanianum occurs in semishaded, moist,

broadleaved forests in low mountains in the northern part

of the Hsuehshan mountain range from Chiaohsi and

Wulai Township to Sanhsia Town (Figure 7).

Phenology. Flowering February-April.

Etymology. The specific epithet is derived from

the name of the location where the type specimen was

collected.

Pollen morphology. Pollen suboblate, with 4 or 5 colpi,

ca. 35.6 £gm ¡Ñ 41.0 £gm (P¡ÑE), exine granulate, tectum

with perforated subunits (Figures 5C, D).

The use of pollen surface structure for the identification

of subgenera and species was analyzed by Mi and

Yang (1991). Two major patterns, inaperaturate and 4-6

colpoidate, generally characterize subgenera Asarum and

Heterotropa, respectively. Huang et al. (1995) prepared a

key based on pollen features to distinguish the species of

Asarum in Taiwan. Morphologically, A. chatienshanianum

is similar to A. macranthum, but the granulate exine

with tectum composed of perforated subunits of the

pollen of the former differs from the latter, which has

large supratectate warts on the exine (Figure 5A).

Palynologically, A. chatienshanianum is more similar to A.

hypogynum Hayata (Figure 5B) than to A. macranthum.

Morphological Notes. Asarum chatienshanianum on

Mt. Peichatienshan was previously misidentified as A.

macranthum. Asarum chatienshanianum has yellowish

green flowers, with a long, narrow cylindrical tube with a

purple, irregularly tessellated internal surface and bilobed

stylar protuberances (Figures 4A-D). To determine more

clearly the differences in the calyx tube morphology more

clearly, we measured 9 flowers of A. chatienshanianum

and 46 flowers of A. macranthum and calculated the

length/width ratio of calyx tube. The results (Figure 8)

show significant differences (p<0.001) between them in

the shape of the calyx tube. Addition, the two taxa differ in

pollen morphology, as mentioned above (Figure 5A, C, D).

2. Asarum tawushanianum C. T. Lu & J. C. Wang, sp.

nov. ¡XTYPE: Pingtung County: Taiwu Township,

Tawushan Nature Reserve, around Kuaiku Lodge,

mixed coniferous-broadleaved forest on mountain

slopes, C. T. Lu et al. 218 (holotype and isotype: TNU).

Z

(Figures 2, 4E-H)

Diagnosis. Affine A. hypogyno, sed floris parvi circ.

2-3 cm in diametrum, calycis tubo brevi cylindrus, ad

collum constrictus sed haud elongatus, calycis lobis

atro-purpureis, basi circum orem intus supra lamellaris

appendices, purpureo-rubellus, differt.

Herbs, perennial. Plants forming extensive

LU and WANG

¡X

Asarum

L. (Aristolochiaceae) in Taiwan

231

Figure 1. Asarum chatienshanianum C. T. Lu & J. C. Wang. 1, Habit; 2, Flower, front view; 3, Dissected flower; 4, Dissected

calyx tube showing inner tessellated ridge; 5, Stamen, outer whorl; 6, Stamen, inner whorl; 7, Style and stigma; 8, Dissected

o va r y.

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Figure 2. Asarum tawushanianum C. T. Lu & J. C. Wang. 1, Habit; 2, Flower, front view; 3, Dissected flower; 4, Dissected

calyx t ube showing inner tessellated ridge; 5, Stamens, outer whorl; 6, Stamens, inner whorl; 7, Style and stigma; 8, Dissected

ov a ry.

LU and WANG

¡X

Asarum

L. (Aristolochiaceae) in Taiwan

233

F igure 3. Asarum villisepalum C. T. Lu & J. C. Wa ng. 1, Habit; 2, Leaf; 3, Flower, front view; 4, Flower, lateral view; 5,

Dissected flower; 6, Dissected calyx tube, showing inner tessellated ridge; 7, Stamens, outer whorl; 8, Stamens, inner whorl; 9,

Style and stigma; 10, Dissected ovary.

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Botanical Studies, Vol. 50, 2009

Figure 4. Floral characters of Asarum chatienshanianum (A- D), A. tawushanianum (E-H), A. villisepalum (I -L), A. macranthum

(M-P), and A. albomaculatum (Q-T). Bar = 10 mm. Notice (1) coloration of calyx lobes: yellowish green in A. chatienshanianum

(A), purple reddish in others (E, I, M, Q), and adaxial surface of calyx lobes with white villi in A. villisepalum (I); (2) shape of

calyx tube: long cylindrical in A. chatienshanianum (B), obconic in A. villisepalum (J), urceolate in A. macranthum (N), shortly

cylindrical in A. tawushanianum (F) and A. albomaculatum (R); (3) pistil characters: lateral stigma with horn-like stylar pro-

tuberance in A. chatienshanianum (C), A. villisepalum (K), and A. albomaculatum (S), term inal or subterm inal stigma without

horn-like stylar protuberance in A. tawushanianum (G) and A. macranthum (O); (4) number of longitudinal ridges: 24 in A. mac-

ranthum (P), 24 in lower part, 12 in upper part in A. villisepalum (L), 10 to 12 in A. albomaculatum (T), more than 12 but less

than 24 in A. chatienshanianum (D) and A. tawushanianum (H).

LU and WANG

¡X

Asarum

L. (Aristolochiaceae) in Taiwan

235

Figure 5. Micromorphology of pollen exine of Asarum. A, A. macranthum; B, A. hypogynum; C-D, A. chatienshanianum; E , A.

tawushanianum; F, A. villisepalum. Bar = 3 £gm.

236

Botanical Studies, Vol. 50, 2009

groundcover. Adventitious roots few, glabrous, as thick

as rhizome. Rhizomes glabrous, repent, elongate; annual

vegetative branches with 2-4 cataphylls at base, cataphylls

membranous, hyaline, sessile, oblong, both surfaces

glabrous, margin hairy, apex obtuse. Leaves long petiolate;

petiole ca. 16 cm long, glabrous adaxially, grooved, dark

brown or purple; blade triangular-oblong to triangular-

ovate, 8.5-12 cm long, 5-6 cm wide, base cordate, basal

lobes 2, 3-4 cm long, 2.5-3 cm wide, apex acuminate;

upper surface usually dark green, lustrous, glabrous,

with white spots, lower surface pale green; young leaves

adaxially and margin with short hairs. Flowering branches

with 2-4 cataphylls at base; cataphylls ovate, glabrous

on both surfaces, margin hairy. Flowers solitary, axillary,

dark purple, decumbent on ground; pedicel glabrous, 1-2

cm long; calyx tube shortly cylindrical, 8-10 mm long,

12-15 mm wide, glabrous outside, reticulate, ridged

inside, longitudinal ridges 12-15; calyx lobes 3, spreading

obliquely, triangular to ovate, ca. 10 mm long, 10-15 mm

wide, adaxially with glands and hairs, abaxially glabrous;

lamellate appendage reddish purple, between orifice

and calyx lobes; calyx tube opening less than 3 mm in

diam., throat constricted but not elongated; orifice ring

well developed; stamens 12, in 2 whorls, 2-2.5 mm long,

filaments short, anthers extrorse, ca. 1.5 mm long, apex

of connectives rounded; ovary superior, locules 6, fused;

styles 6, free; stylar protuberance absent; stigma elliptic,

extrorse, terminal; ovules 10 per locule. Capsule fleshy,

calyx tube persistent. Seeds ellipsoid, brown, ventrally

with fleshy elaiosome. Somatic chromosome number 2n =

24 (Figure 6B).

Additional specimens examined. PINGTUNG

COUNTY. Taiwu Township, Mt. Peitawushan, Kuaiku

Lodge, elev. ca. 2,000 m, C.I Peng 10619 (HAST),

elev. ca. 2,000 m, C.I Peng 13285 (HAST), Tawushan

Nature Reserve, elev. ca. 1,880 m, S.H. Wu & C.I. Hu

1432b (HAST), elev. ca. 2,200 m, C.T. Lu et al. 218

(TNU); Wutai Township, on the way to Mt. Tawushan,

between mountain-hiking entrance and Kuaiku Lodge,

elev. ca. 1,600-2,000 m, C.H. Chen et al. 516 (HAST),

609 (HAST), 6 11 (HAST), elev. ca. 1,500-2,100 m, J.C.

Wang et al. 9051 (TNU, TAI), en route to Mt. Tawushan,

elev. ca. 1,600-2,100 m, T.C. Huang et al. 13628A (TAI),

Kuaiku Lodge, elev. ca. 2,200 m, M.J. Wu 1850 (TAI).

Distribution and habitat. Endemic to Taiwan. Currently

known only from Tawushan Nature Reserve around

Kuaiku Lodge at high elevations in southern Taiwan

(Figure 7). Asarum tawushanianum inhabits heavily

shaded, moist mixed coniferous-broadleaved forests on

mountain slopes.

Phenology. Flowering April to May.

Etymology. The specific epithet is derived from the

name of the location where the type specimen was

collected.

Figure 6. Somatic chromosome number of Asarum. A, A. chatienshanianum (2n = 24); B, A. tawushanianum (2n = 24); C, A.

villisepalum (2n = 24). Bar = 10 £gm.

Fig ure 7. Geographic distribution of Asarum chatienshania-

num (¡´), A. tawushanianum (

„\

) and A. villisepalum (¡¶) .

LU and WANG

¡X

Asarum

L. (Aristolochiaceae) in Taiwan

237

Pollen morphology. The pollen grains of Asarum

tawushanianum are oblate spheroid with 4-6 colpi, 33.6

£gm ¡Ñ 37.8 £gm (P¡ÑE), tectum rugulate-perforate with

large irregular supratectate warts (Figure 5E). Pollen of A.

tawushanianum resembles the pollen of A. macranthum

even though in gross morphology the plants are more

similar to A. hypogynum.

Morphological Notes. Huang et al. (1995) treated

Asarum tawushanianum as a high-altitude form of Asarum

macranthum restricted to the south-central mountain

range. They believed it to be similar to A. albomaculatum

Hayata and to A. hypogynum in appearance. The vegetative

characters A. macranthum, such as the green leaves with

adaxial white blotches, and paler abaxially. The indistinct

leaf venation is the same as in A. albomaculatum. The

flowers arising from young leaves or directly from

branches and the styles lacking a protuberance resemble A.

hypogynum. Vegetative morphology and floral characters

show this taxon to be more similar to A. hypogynum than

to A. macranthum or A. albomaculatum (Figures 4M-T).

Asarum tawushanianum differs from A. hypogynum in

having smaller flowers, (ca. 2-3 cm in diam. versus ca.

5 cm in the latter), shortly cylindrical calyx tube, throat

constricted but not elongated and calyx lobes totally dark

purple with a reddish purple lamellate appendage at the

base (which is white in the latter).

3. Asarum villisepalum C. T. Lu & J. C. Wang, sp. nov.¡X

TYPE: Ilan County: Nanao Township, Shenmihu

Nature Preserve, virgin broadleaved forest dominated

by Machilus, Castanopsis and Cyclobalanopsis, with

abundant epiphytic ferns and orchids, on somewhat

exposed site by a trail, elev. ca. 1,000-1,150 m, C.T. Lu

579 (holotype: TNU; isotype: TNU). ZdZ

(Figures 3, 4I-L)

Diagnosis. Affine A. macrantho, sed foliis margine

undulatis, floris atro-maroon, calycis lobis supra villosis,

calycis tubo intus elevato-reticulatus, albus, supra 1/2

longitudinalibus 12 infra 1/2 longitudinalibus 24, stylis

apice bilobis, cornuatus et stigmatibus lateralis, differt.

Perennial herbs. Plants forming clumps. Adventitious

roots glabrous, as thick as rhizome. Rhizomes glabrous,

suberect; annual vegetative branch with 2 cataphylls at

base; cataphylls membranous, hyaline, sessile, oblong,

both surfaces glabrous, margin hairy, apex obtuse.

Leaves long petiolate; petiole ca. 9-15 cm, adaxially

hairy, grooved, dark purple; blade triangular-oblong to

triangular-ovate, 10-14 cm long, 7-13 cm wide, margin

undulate, base cordate, basal lobes 2, 3-4 cm long, 3-4

cm wide, apex acute to acuminate; upper surface usually

dark green, glabrous, with white blotches, lower surface

pale green; young leaves adaxially and margin usually

with short hairs. Flowering branches with 2 cataphylls at

base, cataphylls ovate, glabrous on both surfaces, margin

hairy. Flowers solitary, axillary, dark maroon, decumbent

on ground; pedicel glabrous, ca. 1 cm long; calyx tube

obconic, 10-14 mm long, basally 7-8 mm wide, apically

11-14 mm wide, glabrous outside; calyx lobes 3, spreading

obliquely, usually not undulate, triangular to ovate, 8-15

mm long, 11-15 mm wide, abaxially glabrous, adaxially

white villous; tubercles between orifice and calyx lobes

white; inside reticulate ridged, longitudinal ridges 24

basally, 12 apically; calyx tube opening less than 8 mm in

diam.; orifice ring ca. 1 mm wide; stamens 12, in 2 whorls,

2-2.5 mm long, filaments short, anthers extrorse, ca. 1.5

mm long, apex of connective rounded; ovary semi-inferior,

locules 6, fused; styles 6, free; stylar protuberances 2

lobed, apex horn-like; styles equal to or slightly shorter

than calyx tube; stigma elliptic or lachrymiform, lateral on

style; ovules 8 per locule. Somatic chromosome number

2n = 24 (Figure 6C).

Additional specimens examined. ILAN COUNTY:

Nanao Township, Chinyang Nanao Broadleaved Forest

Preserve, elev. ca. 1,100 m, C.I Peng et al. 13812 (HAST),

13813 (HAST); Shenmihu Nature Preserve Area, elev. ca.

1,000-1,150 m, C.C. Liao et al. 1758 (HAST), C.T. Lu 579

(TNU), Lake Shenmihu, elev. ca. 1,000 m, S.F. Huang et

al. 5200 (TAI), en route from Shenmihu control station

to Shenmihu broadleaved forest, elev. ca. 1,355-1,030 m,

T.Y. Liu et al. 139 (HAST, TNU), elev. ca. 1,260-1,200

m, T.Y. Liu et al. 169 (HAST, TNU), Chinyang Village,

Lake Shenmihu, elev. ca. 1,000-1,100 m, C.H. Chen et al.

665 (HAST, TNU); Mt. Fanpaoshan, en route from hiking

entrance to ridge of mountain, elev. ca. 1,500 m, C.C.

Liao & C.C. Chen 1799 (HAST). HUALIEN COUNTY.

Hsiulin Township, Hoping logged trail 28-32 K, S.C. Liu

2619 (TNU).

Distribution and habitat. Endemic to Taiwan, only in

Shenmihu Nature Preserve Area, ca. 1,000 m and Hoping

logged trail (Figure 7). Asarum villisepalum occurs in

heavily shaded, moist, broadleaved forests on mountain

slopes.

Phenology. Flowering from March to May.

Etymology. The specific epithet refers to the dense

white hairs on the upper surface of the calyx lobes.

Figure 8. Length/width ratio of calyx tube of A. chatiensha-

nianum (¡½, sample size = 9) and A. macranthum (¡´, sample

size = 46), showing significant difference in this character (t

test, p < 0.001). (box presents sample size).

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Botanical Studies, Vol. 50, 2009

Pollen morphology. The pollen of Asarum villisepalum

is suboblate with 4-6 colpi, 36.5 £gm ¡Ñ 42.5 £gm (P¡ÑE),

tectum rugulato-perforate with median supratectate warts

(Figure 5F).

Morphological Notes. Huang et al. (1995) regarded

Asarum villisepalum as represent infraspecific variation

in Asarum macranthum, due to their similarity in gross

morphology. Our detailed comparison revealed that A.

villisepalum differs from A. macranthum as follows: leaf

margins undulate, adaxial surface of calyx lobes with long

white villi, calyx tube reticulate, ridged inside, longitudinal

ridges 12 apically, 24 basally (Figure 4L), and apex of

stylar protuberance bilobed and horn-like. The dark

maroon flowers of A. villisepalum are also different from

those of A. macranthum, which has the tube white outside

(Figure 4N). Additionally, the ridges inside the calyx tube

are white instead of purple in A. macranthum (Figure 4L).

Key to the taxa of Taiwanese Asarum

1. Leaves membranous, both surfaces hairy, without white spot or blotch on upper surface; rhizomes hairy; roots more

slender than rhizome; ovary inferior, hairy; calyx tube without an orifice rim; styles fused to form a stylar column.

2. Current year¡¦s stem suberect, with 2, nearly opposite leaves; leaves usually triangular to ovate; apex of calyx lobes

caudate; filaments longer than anthers .......................................................................................................A. caudigerum

2. Current year ¡¦s stem repent, with 1-3 alternate leaves; leaves usually ovate; apex of calyx lobes round; filaments

shorter than anthers .......................................................................................................................................A. epigynum

1. Leaves coriaceous, glabrous or hairy along veins and margin, usually with white spots or blotches on upper surface;

rhizomes glabrous; roots equal to or slightly less than rhizomes in diam.; ovary superior or half-inferior, glabrous; calyx

tube with an orifice rim; styles free.

3. Leaves glabrous or scarcely hairy on veins on upper surface; stylar protuberance entire; throat of tube severely

constricted below calyx lobes.

4. Plants robust; leaves to 30 cm long; flowers ca. 5 cm in diam.; calyx lobes brownish purple, margin usually green

or yellow ................................................................................................................................................ A. hypogynum

4. Plants slender; leaves less than 15 cm long; flowers ca. 2-3 cm in diam.; calyx lobes dark purple, margin dark

purple

.............................................................................................................................................. A. tawushanianum

3. Leaves usually hairy on veins and margin; stylar protuberance bifid;; throat of tube usually slightly constricted below

calyx lobes.

5. Veinlets on lower surface of leaves indistinct (Figure 9B); calyx tube cylindrical, longitudinal ridges inside tube

12 or less; stigma round or lachrymiform, lateral on style; stylar protuberances horn-like at apex of style.

6. Plant body robust; annual vegetative branches close together; leaves usually triangular-cordate, apex acuminate

....................................................................................................................................................A. albomaculatum

6. Plant body slender; annual vegetative branches far apart; leaves triangular to sagittate, apex acute to acuminate

or triangular-oblong and apex obtuse.

7. Blade triangular to sagittate, apex acute to acuminate; base of calyx lobes with lamellate tubercle ................

................................................................................................................................................ A. crassusepalum

7. Blade triangular to triangular-oblong, apex obtuse; base of calyx lobes without tubercles .............................

........................................................................................................................................... A. taipingshanianum

5. Veinlets on lower surface of leaves distinct (Figure 9A); calyx tube urceolate, cylindrical or obconic, longitudinal

ridges inside tube more than 12; stigma hook-like or lachrymiform, terminal, subterminal or lateral on style; stylar

protuberance winged on both margins or horn-like at apex of style.

8. Calyx tube urceolate, with 24 longitudinal ridges inside tube; stigma hook-like, terminal or sub-terminal on

style; stylar protuberance winged on both margins at apex of style

............................................. A. macranthum

8. Calyx tube cylindrical or obconic, with more than 12 but less than 24 longitudinal ridges inside tube; stigma

lachrymiform, lateral on style; stylar protuberance horn-like at apex of style.

9. Flowers green or yellowish green; calyx lobes spreading, flat, adaxial surface pubescence; calyx tube

narrowly cylindrical, with more than 12 but less than 24 longitudinal ridges inside tube ...............................

.......................................................................................................................................... A. chatienshanianum

9. Flowers maroon; calyx lobes spreading, undulate, adaxial surface white villous; calyx tube obconic, inner

wall apically with 12 longitudinal ridges, basally with 24 longitudinal ridges ..........................A. villisepalum

LU and WANG

¡X

Asarum

L. (Aristolochiaceae) in Taiwan

239

Acknowledgements. The authors thank David Boufford

and three anonymous reviewers for improving the

manuscript, Qiner Yang for helping to improve our Latin

diagnosis.

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F igure 9. Venation of lower surface of leaves of A. macran-

thum (A) and A. albomaculatum (B) showing di stinct and

indistinct veinlets.

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