Botanical Studies (2008) 49: 73-82.

*

Corresponding author: E-mail: bopeng@sinica.edu.tw; Tel:

+886-2-2789-3821; Fax: +886-2-2789-1623.

INTRODUCTION

The genus Acmella Rich. (Asteraceae) comprises 30

species and 9 additional infraspecific taxa that are mainly

distributed in the tropical and subtropical regions around

the world (Jansen, 1985b). One of the most distinct and

recognizable members of the genus is Acmella oleracea

(L.) R. K. Jansen, a species characterized by its large,

cylindric discoid capitula. For centuries, Acmella oleracea

has been widely cultivated for horticultural, medicinal,

insecticidal, and culinary purposes (Jansen, 1985b; Lee,

1994; Hind and Biggs, 2003). In particular, this species is

famous as a folklore remedy for toothache and for throat

and gum infections, earning it the English nickname, the

"toothache plant." It has been long known that chewing

the capitula of Acmella oleracea will numb the mouth and

temporarily relieve dental and oral pain (Jansen, 1985b;

Hind and Biggs, 2003), and its application for this is still

widespread in Taiwan (Chung, 1997; Chiu and Chang,

1998) and many other parts of the world (Hind and

Biggs, 2003). Despite its long and wide application as a

folk medicine, the taxonomy of Acmella oleracea and its

congeners in Taiwan has been chaotic.

Augustine Henry (1896), based on his collections

from Bankinsing (currently Wanluan Township, Pingtung

County, A. Henry 812) and South Cape (currently Oluanpi,

Hengchun Township, Pingtung County, A. Henry 219) in

southern Taiwan, was the first to document the existence of

Acmella paniculata (Wall. ex DC.) R. K. Jansen (mis-typed

as Spilanthes ¡¥acinella¡¦ L.) on the island. Subsequently

Hayata (1904) and Kitamura (1941), in their studies

of Taiwanese Compositae, enumerated it as Spilanthes

acmella (L.) Murray. In 1950 Koster and Philipson studied

the type specimen of Verbesina acmella L., basionym

of Spilanthes acmella (L.) Murray, and noted that this

specimen actually represents a species of Blainvillea

Cass., rendering S. acmella auct. non (L.) Murray for the

species. The next available name Spilanthes paniculata

Wall. ex DC. was therefore taken as the correct name for

the species (Koster and Philipson, 1950). Although this

treatment was soon taken up by Hara (1951) and Kitamura

(1969), Li (1978) did not seem to be aware of these works

and instead followed the earlier works of Hayata (1904)

and Kitamura (1941) in using the name Spilanthes acmella

(L.) Murray in the first edition of the Flora of Taiwan.

Moreover, Li¡¦s treatment (1978) of Spilanthes acmella

was erroneously accompanied by a line drawing (based

on M.T. Kao s.n.1962, TAI) portraying the cultivated

Acmella oleracea (as Spilanthes acmella), which further

complicated the taxonomy of Spilanthes in Taiwan. The

confusing of various species and misapplication of names

is commonplace among folk herbalists (e.g., Liu and Ou,

1981; Chung, 1997) and anonymous information sources

posting on the Internet (Hind and Biggs, 2003).

Based on the cladistic analysis of morphological and

cytological characters of Spilanthes Jacq. (sensu Moore,

1907), Jansen (1981, 1985b) re-circumscribed the genus

and restored the generic status of Acmella, which had long

been subsumed to a section under Spilanthes by earlier

taxonomists. Jansen¡¦s taxonomy was followed by Peng

et al. (1998) in the second edition of the Flora of Taiwan,

in which two discoid species, the cultivated A. oleracea

(L.) R. K. Jansen and the indigenous A. paniculata (Wall.

ex DC.) R. K. Jansen, were described and illustrated

with line drawings and color photographs. In the same

year, Chiu and Chang (1998) illustrated three species of

Acmella (as Spilanthes) in a book on medicinal plants

Notes on Acmella (Asteraceae: Heliantheae) in Taiwan

Kuo-Fang CHung

1

, Yoshiko KOnO

1

, Chiu-Mei WANG

2

, and Ching-I PeNG

1,

*

1

Herbarium (HAST), Research Center for Biodiversity, Academia Sinica, Nangang, Taipei 115, Taiwan

2

Department of Botany, National Museum of Natural Science, 1 Guancian Rd., Taichung, Taiwan

(Received June 25, 2007; Accepted December 2, 2007)

ABSTRACT.

In several recent pictorial guides on Taiwanese wildflowers and medicinal plants, color

photographs of unknown Acmella species with radiate capitula were erroneously identified as Acmella

paniculata or its synonyms, despite this plant¡¦s having discoid capitula. As nearly all books attribute medicinal

properties to these Acmella, it is imperative to clarify their taxonomy. In this article we document the

occurrence of five species of Acmella in Taiwan, two with radiate capitula that were not reported for the flora

of this island before, namely: A. brachyglossa and A. ciliata. Detailed description and color photographs and

chromosome cytology of all five species of Acmella are provided to aid in identification.

Keywords: Acmella brachyglossa; Acmella ciliata; Acmella oleracea; Acmella paniculata; Acmella uliginosa;

Chromosome cytology; Compositae; Invasive plants; Naturalized plants; Spilanthes.

TAxONOmy

74

Botanical Studies, Vol. 49, 2008

in Taiwan. In this work, they included the cultivated

Acmella oleracea (as S. acmella L. var. oleracea Clarke),

a species with inconspicuous ray florets (as Spilanthes

paniculata Wall. ex DC.), and another species with radiate

capitula [as Spilanthes acmella (L.) Murray]. Subsequent

to the publication of the second edition of the Flora of

Taiwan (Peng et al., 1998) and a Chinese version of

the simplified flora (Peng and Chung, 1999), the name

Acmella paniculata (Wall. ex DC.) R. K. Jansen appeared

in two pictorial guides to the wild flowers of Taiwan

(Lin, 2003; Dai, 2006). The color photographs in the two

books, however, show Acmella species with noticeable

radiate capitula that are similar to those of the ¡¥¡¦Spilanthes

acmella¡¦ in the work of Chiu and Chang (1998). In 2007,

Chung et al. reported the naturalization of a radiate species,

Acmella uliginosa (Sw.) Cass., in northern Taiwan. This

species, however, differs considerably from the radiate

species illustrated in Chiu and Chang (1998), Lin (2003),

and Dai (2007) in having much smaller capitula.

Because most publications in Taiwan (e.g., Chiu and

Chang, 1998; Lin, 2003; Dai, 2006) and online reports

attribute medicinal properties to these unknown radiate

Acmella, naming these plants correctly is important.

Additionally, a timely report on the naturalization of alien

species is crucial to effectively controlling and eradicating

potential invasive species (Wu et al., 2003; Xu et al., 2004;

Yang et al., 2005). To clarify the taxonomy of Acmella

in Taiwan, we surveyed herbarium collections, consulted

folk herbalists, and visited localities where photographs of

Acmella with radiate capitula were taken. As a result, we

document the existence of two additional Acmella species

with ray florets, which are new to the flora of Taiwan. A

key to the species in Taiwan and their color photographs

are provided to aid in their identification. Additionally we

summarize and tabulate the sources of misapplied names

of Acmella occurring in Taiwan (Table 1).

TAxONOmIC TREATmENT

Acmella Rich. in Pers., Syn. Pl. 2: 472. 1807; Jansen, Syst.

Bot. Monogr. 8: 19. 1985.¡XSpilanthes sect. Acmella

(Rich.) DC., Prodr. (DC.) 5: 620. 1836. ª÷¶s¦©ÄÝ

Pantropical, about 30 species, mainly distributed in

the tropics and subtropics. Many species have become

naturalized and invasive. In Taiwan, one native species,

one cultivated species, and three naturalized species are

found.

Key to species of Acmella in Taiwan

1. Capitula discoid (without ray florets).

2.

Leaves ovate to deltoid, leaf bases broad obtuse,

truncate to slightly cordate; capitula cylindric, more

than 1 cm wide; involucral bracts 15-18, triseriate;

mature achenes without evident cork-like margins .....

............................................................ 3. A. oleracea

2.

Leaves lanceolate, elliptic to narrowly ovate, leaf

bases attenuate or cuneate; capitula cone-shaped, less

than 1 cm wide; involucral bracts 9-12, biseriate;

mature achenes with evident cork-like margins ..........

........................................................... 4. A. paniculata

1. Capitula radiate (with ray florets).

3.

Leaves ovate to deltoid, leaf bases broad obtuse,

truncate to slightly cordate; capitula ovoid; mature

achenes with evident cork-like margins ......................

................................................................ 2. A. ciliata

3.

Leaves lanceolate, elliptic to narrowly ovate, leaf

bases attenuate or cuneate; capitula cone-shaped;

mature achenes without evident cork-like margins.

4.

Disc florets 4- or 5-merous, corollas light yellow

or greenish, ray florets relatively inconspicuous;

involucral bracts 7-11, biseriate; achenes of disc

florets 1.5-3 mm long .............. 1. A. brachyglossa

4.

Disc florets 4-merous, corollas yellow to orange,

ray florets conspicuous; involucral bracts 5-6,

uniseriate; achenes of disc florets 1.2-1.8 mm long

....................................................... 5. A. uliginosa

1.

Acmella brachyglossa Cass., Dict. Sci. nat. (ed. 2) 50:

258. 1827; Jansen, Syst. Bot. Mongr. 8: 73. 1985.

µu¦Þªáª÷¶s¦©¡]·sÀÀ¤¤¦W¡^ Figures 1A, 1D, 1Ja

Annual herbs. Plants 10-30 cm tall, stems decumbent

Table 1. Sources of misapplied names of Acmella in Taiwan.

Acmella brachyglossa

Acmella ciliata

Acmella oleracea Acmella paniculata

Li (1978)

. ¡¥Spilanthes acmella¡¦ . ¡¥Spilanthes acmella¡¦

Liu & Ou (1981)

1

. ¡¥Spilanthes acmella¡¦ . ¡¥Spilanthes acmella¡¦

Chung (1997)

2

.. ¡¥Spilanthes acmella¡¦

Chiu & Chang (1998)

3

.. ¡¥Spilanthes paniculata¡¦ .. ¡¥Spilanthes acmella¡¦

Lin (2005)

4

. ¡¥Acmella paniculata¡¦

Dai (2006)

5

. ¡¥Acmella paniculata¡¦

.Misapplied in description.

.Misapplied in illustration, including line drawings or photographs.

1

¼B°ê¬W¡B¼Ú¼íªÛ;

2

Áé¿õ¥þ;

3

ªô¦~¥Ã¡B±i¥ú¶¯;

4

ªL¤å´¼;

5

À¹¼w¬u.

CHUNG et al. ¡X

Acmella

(Asteraceae) in Taiwan

75

Figure 1. Acmella Rich. in Taiwan. A, habit of A. brachyglossa; B, habit of A. ciliata; C, habit of A. uliginosa; D-I, radiate (D-F, I) and

discoid (g, H) capitula: D, A. brachyglossa; E & F, A. ciliata; g, A. oleracea; H, A. paniculata; I, A. uliginosa; J, achenes, the scale bar

= 1 mm: a, A. brachyglossa; b, A. ciliata; c, A. oleracea; d, A. paniculata; e. A. uliginosa.

76

Botanical Studies, Vol. 49, 2008

to usually erect, occasionally rooting at nodes, green, red

to dark purple, glabrous to moderately pilose. Petioles

5-37 mm long, sparely to moderately pilose, narrowly

winged; leaf blades narrowly ovate to ovate, 1.8-10 ¡Ñ 0.8-6

cm, apex acute to usually acuminate, margins sinuate to

coarsely dentate, base attenuate, glabrous to sparely pilose

on both sides. Peduncles 4-12.8 cm long, sparely pilose.

Capitula, solitary, conical, 6.3-13 mm high, 6.5-9.5 mm in

diameter; involucral bracts 7-11, biseriate, outer series 3-5,

narrowly to broadly ovate, 3-5.2 ¡Ñ 0.9-3.2 mm, inner series

3-6, lanceolate to ovate, 3.4-4.6 ¡Ñ 1-2.5 mm; receptacle

5-11 mm high, 1-2 mm in diameter; palea stramineous,

often purple-red tinge in early flowering stage, 3.5-4.5 ¡Ñ

0.5-0.9 mm; ray florets 5-8, bisexual, corollas pale yellow,

2-3.1 mm long, tubes 0.9-1.5 mm long, limbs 0.5-1.7 ¡Ñ

0.5-1.5 mm; disc florets 107-222, bisexual, pale yellow,

corollas 4- or 5-merous, 1.5-2.1 mm long, tube 0.4-0.7

mm long, throat 1-1.5 mm long, lobe triangular, 0.2-0.4

¡Ñ 0.2-0.3 mm. Achenes dark brown to black, 1.8-2.3 ¡Ñ

0.5-0.9 mm, surface strigose, margin densely ciliate with

straight-tipped hairs but without evident cork-like margin;

pappus of two subequal bristles, the longer bristle 0.5-1.1

mm long, the shorter 0.3-1 mm long.

Specimens examined. Taichung City: Nantun District,

15 Mar 2007, K.-F. Chung 1714 (HAST), C.-M. Wang

9773 (TnM). nantou Co.: Mingjiang Township, Chieh-

Yuan Herb garden, 29 Mar 2007, C.-I Huang et al. 3105

(HAST); Luku Township, Guanghsing elementary School,

29 Mar 2007, C.-I Huang et al. 3106 (HAST). Tainan Co.:

Paiho Township, Tatungshan, 26 Oct 1992, H.-F. Yen 6

(HAST).

Distribution and Notes. Acmella brachyglossa is a

weedy species commonly found in Central America,

northern South America, and the West Indies (Jansen

1985b). In a distribution map of his monograph, Jansen

(1985b) also indicated the occurrence of this species in

Thailand, however, without citing voucher specimens.

In Taiwan (Figure 2), the first documented specimen

was collected by Ye n in 1992 (H.-F. Yen 6, HAST) from

Tainan County. In The Illustrated Medicinal Plants of

Taiwan, volume 5 (Chiu and Chang, 1998), a plant in a

color photograph that clearly shows all the characters

of Acmella brachyglossa was referred to as Spilanthes

paniculata, while the authors suggested that this plant

probably represented a new record in Taiwan. According

to Chiu and Chang (1998), that plant grows in moist places

and along ditches. Although the history of its introduction

to Taiwan is not known, Acmella brachyglossa appears

to have been cultivated and propagated for more than

a decade by folk herbalists in Taiwan for its alleged

medicinal properties, i.e. cure for scurvy, toothache,

and throat and gum infections (pers. comm. Kuo-Hsuan

Hsu, 2007). This species can be easily distinguished

from congeners in Taiwan by its pale yellow or greenish

capitula and relatively inconspicuous ray florets, purple

tinged pales in the early flowering stage, and densely

ciliate achenes without an evident cork-like margin.

Given its weedy behavior in other parts of the world, A.

brachyglossa is likely to become widespread and rampant

in Taiwan.

Chromosome cytology. The somatic chromosome

number and chromosome morphology at mitotic

metaphase of this species are reported here for the first

time. The chromosome number 2n = 78 (Figure 3A) was

observed for a plant collected in Taichung City (Chung

1714, HAST), which is concordant with a previous report

of n = 39 for plants collected from Ecuador and Venezuela

(Jansen, 1985a). The chromosome length at mitotic

metaphase varies gradually from about 2.3 £gm to about

1.0 £gm. Some chromosomes appear to have centromeres

at median and submedian positions, but some have

centromere positions that are uncertain. Satellites were not

observed.

2.

Acmella ciliata (Kunth) Cass., Dict. Sci. nat. (ed. 2)

24: 331. 1822; Jansen, Syst. Bot. Mongr. 8: 36. 1985.¡X

Spilanthes ciliata Kunth in Humboldt, Bopland &

Kunth, Nov. Gen. Sp. (folio ed.) 4: 163. 1820. ¤Ñ¤å¯ó

(¤¤¦W¥X³B: Chiu and Chang, 1998)

Figures 1B, 1E, 1F, 1Jb

Perennial herbs 30-80 cm tall. Stems usually decumbent

to ascending, rooting at nodes, green to purple, glabrous to

sparsely pilose. Petioles 0.7-4 cm long, narrowly winged,

glabrous or sparsely pilose; leaf blades ovate to broadly

Figure 2. Distribution map of Acmella Rich. in Taiwan (A. ol-

eracea excluded). Acmella brachyglossa (¡¼), A. ciliata (¡¹), A.

paniculata (¡´), and A. uliginosa (¡¶).

CHUNG et al. ¡X

Acmella

(Asteraceae) in Taiwan

77

ovate, 2.3-7.5 ¡Ñ 1-5.9 cm, apex acute, margins denticulate

to coarsely dentate, base usually truncate or cordate,

glabrous to sparsely pilose on both sides. Peduncles 1-7.4

cm long, sparsely to moderately pilose. Capitula radiate,

solitary or 2 or 3, terminal or axillary, broadly ovoid,

6-10.5 mm high, 5.5-9.5 mm in diameter; involucral bracts

7-10, biseriate, outer series 3-5, narrowly to broadly ovate

or elliptic, 4-6.9 ¡Ñ 1-2.3 mm, inner series 3-6, lanceolate

to ovate or elliptic, 2.8-6.1 ¡Ñ 1-2.9 mm; receptacles 3.8-7.4

mm high, 0.8-1.9 mm in diameter; palea stramineous,

3-4.5 ¡Ñ 0.4-0.8 mm; ray florets 5-10, bisexual, corollas

yellow orange, 2.5-6.5 mm long, tubes 0.9-2 mm long,

limb 1.2-4.7 mm long, 1.1-3 mm wide; disc florets 90-177,

bisexual, yellow-orange, corollas 5-merous, 1.5-2 mm

long, tube 0.3-0.6 mm long, throat 1-1.5 mm long, lobes

triangular, 0.2-0.4 ¡Ñ 0.2-0.3 mm. Achenes black, 1.4-2.2

¡Ñ 0.5-1 mm, long, without shoulders, margins sparely to

moderately ciliate, with evident cork-like margins, pappus

usually absent or sometimes of 2 very short subequal

bristles less than 1 mm long.

Specimens examined. Taipei City: Zhongshan District,

Dajia Riverside Park, 3 Apr 2006, M.-J. Jung 040301

(TAIF), 040302 (TnM), 28 Mar 2007, C.-I Huang &

K.-F. Chung 3100 (HAST). Miaoli Co.: Dahu Township,

Kungching Bridge, 30 Nov 2002, C.-H. Yu 440 (HAST);

nanjuang Township, nanjuang, 23 Mar 2007, C. M. Wang

& C. Y. Li 9840 (TnM), 28 Mar 2007, C.-I Huang &

K.-F. Chung 3099 (HAST), 13 Jun 2007, C.-I. Peng, K.-F.

Chung, and Y. Kono 21144 (HAST).

Distribution and Notes. Acmella ciliata is native to

northern South America and has naturalized in Celebes,

India, Sumatra, and Thailand (Jansen, 1985b). In Taiwan

(Figure 2), the earliest known documentation of this

species (Chiu and Chang, 1998) erroneously referred

to it as Spilanthes acmella and described it as a native

species in the moist environments and hill ditches in the

southern part of the island. Lin (2005) and Dai (2006) also

misidentified A. ciliata as A. paniculata. Acmella ciliata

is easily distinguishable from A. paniculata by its larger,

broadly ovoid capitula, conspicuous ray florets (5-10), and

shorter achenes (1.4-2.2 vs. 2.2-2.9 mm long) that lack

ciliated margins at the mature stage. Although the exact

origin of A. ciliata in Taiwan is not traceable, this species

probably has been cultivated in Taiwan for more than

a decade by folk herbalists for its medicinal properties

(Chiu and Chang, 1998). Known herbarium records of

this species indicate that Acmella ciliata is naturalized

on damp, water-clogging, and disturbed areas in central

and northern parts of Taiwan. In our recent field trips to

southern China, we also found this species naturalized in

the Guangxi Zhuangzu Autonomous Region (Chongzhuo,

Peng et al. 20326, HAST; Hechi, Peng et al. 21060,

HAST).

Chromosome cytology. The somatic chromosome

number and chromosome morphology at mitotic

metaphase of this species are reported here for the first

time. The chromosome number 2n = 78 (Figure 3B) was

observed for plants collected from Taipei City ( Huang &

Figure 3. Somatic chromosomes at mitotic metaphase in Acmella. A, A. brachyglossa, 2n = 78, from Chung 1714 (HAST); B, A. cilia-

ta, 2n = 78, Huang & Chung 3100 (HAST); C, A. oleracea, 2n = 52, from a cultivated plant at the experimental greenhouse, Academia

Sinica; D, A. paniculata, from Chung 1715 (HAST); E, A. uliginosa, from Peng & Chung 21013 (HAST). Arrows indicate satellite

chromosomes.

78

Botanical Studies, Vol. 49, 2008

Chung 3100, HAST) and Nanjuang, Miaoli County (Peng

et al. 21144, HAST). This chromosome number of 2n

= 78 is concordant with the previously reported meiotic

chromosome number of n = 39 for plants collected from

ecuador, and Zamora (Jansen, 1985a). The chromosome

length at mitotic metaphase varies gradually from about

2.1 £gm to about 1.0 £gm. Some chromosomes appear to

have centromeres at median and submedian positions, but

we were uncertain about the exact centromere positions of

others. Satellites were not observed.

Interestingly, a chromosome number 2n = 65

(pentaploid based on x = 13) was observed for a plant

collected from Nanjuang, Miaoli County (Huang and

Chung 3099, HAST). This plant, growing alongside many

typical Acmella ciliata that had set abundant achenes,

had slightly narrower leaves and produced no achene in

either the field or the experimental greenhouse, signs of a

possible hybrid origin. Although 2 n = 65 has been reported

for A. oppositifolia (Lam.) R.K. Jansen, a close relative of

A. ciliata, a pentaploid with 2n = 65 has not been reported

for A. ciliata (Jansen, 1985a). Further studies are needed to

understand the origin of this unusual chromosome number.

3.

Acmella oleracea (L.) R. K. Jansen, Syst. Bot. Monogr.

8. 65. 1985; Peng et al., Fl. Taiwan 2nd ed. 4: 812, pl.

375, photo 406 (left). 1998; Peng & Chung in Yang et

al., Manuals Taiwan Vas. Pl. 4: 220, fig. 237, photo 405

(left). 1999; Hind & Biggs, Curtis¡¦s Bot. Mag. 20: 33,

pl. 460, fig. 2003.¡XSpilanthes oleracea L., Syst. Nat.

2: 534. 1767; Huang, Fl. Taiwan 6: 141, ¡¥S. oleracea

Clarke¡¦.¡X Spilanthes acmella var. oleracea (L.) C. B.

Clarke ex Hook. f., Fl. Brit. India 3: 307. 1881. ÅK®±ÀY

Figures 2g, 2Jc

Spilanthes acmella auct. non (L.) Murray: Li, Fl. Taiwan 4:

945, pl. 1256. 1978, pro parte.

Annual herbs up to 90 cm tall. Stems usually decumbent

to ascending, green to red, glabrous. Petioles 2-6.5 cm

long, narrowly winged, glabrous or very sparsely pilose;

leaf blades broadly ovate to deltate, 5-10.5 ¡Ñ 4-8 cm, apex

short acuminate to acute, margins dentate, base truncate to

short attenuate, glabrous on both sides. Peduncles 3.5-12.5

cm long, sparsely to very sparsely pilose. Capitula discoid,

solitary, terminal, cylindrical, 10.5-23.5 mm high, 11-17

mm in diameter; involucral bracts 15-18, triseriate,

margins entire to sinuate, outer series 5-6, narrowly ovate

to lanceolate or sometimes ovate, 5.8-7.3 ¡Ñ 2.1-2.8 mm,

middle series 5-6, lanceolate, 5.8-7.3 ¡Ñ 2.1-2.8 mm, inner

series 5-6, lanceolate, 5.5-6.5 ¡Ñ 1.3-2 mm; receptacles

8.3-21.5 mm high, 3.5-0.5 mm in diameter, occasionally 2

per capitulum, apex acute; palea stramineous, often with

a purple-red tinged when young, 5.3-6.2 ¡Ñ 1-1.2 mm; disc

florets numerous, bisexual, yellow, corollas 5-merous,

2.7-3.3 mm long, tube 0.5-0.7 mm long, throat 2.2-2.6

mm long, lobes 0.3-0.6 ¡Ñ 0.2-0.4 mm. Achenes black,

2-2.5 ¡Ñ 0.9-1.1 mm, without evident cork-like margins and

shoulders, margins moderately ciliate with straight-tipped

hairs, pappus 2, inconspicuous, 0.3-1.5 1 mm long.

Specimens examined. Taipei City: Taan District, 23

Oct 1963, M.-T. Kao & C.-C. Chuang 5494 (TAI), nTu

campus, 15 Jun 1962, M. T. Kao s.n. (TAI); neihu District,

8 Aug 1943, Y. Simada 6145B (TAI); Nangang, cultivated,

26 May 1987, C.-I Peng 10869 (HAST). Yilan Co.:

Jhuangwei Township (cultivated), 9 Apr 2002, C.-C. Lin

498 (TAIF). Hsinchu Co.: Hsinfeng Township, Hsinfeng

to Tamei Village, cultivated, C.-I Peng 6389 (HAST).

Taichung Co.: Tanzih Township, Dongbao Village,

cultivated, 2 Jul. 2007. C.-M. Wang 10333 (TnM). nantou

Co.: Puli Township, Tapingting Farm, 17 Jul 1968, C.-C.

Hsu 4626 (TAI).

Distribution and Notes. This plant is known mainly

from cultivation in Taiwan and occasionally escapes into

the field in other parts of the world (Jansen, 1985b; Hind

and Biggs, 2003). Acmella oleracea is characterized by

its large and cylindric discoid capitula, a feature that is

unique for the genus. For centuries, this highly ornamental

plant has been admired for its medicinal value and widely

cultivated around the world. Based on a cladistic analysis

of morphological characters, Jansen (1985b) suggested that

A. oleracea was mostly likely derived through cultivation

from Acmella alba (L¡¦Her.) R. K. Jansen in central Peru.

In Taiwan, Acmella oleracea is commonly cultivated for

its horticultural and medicinal properties, especially for

relieving toothache (Lee, 1994; Chung, 1997; Chiu and

Chang, 1998).

Chromosome cytology. The somatic chromosome

number of 2n = 52 and chromosome morphology at mitotic

metaphase are reported here (Figure 3C) from plants

cultivated in the experimental greenhouse, Academia

Sinica. Our observation differs considerably from two

previous reports from India (Mathew and Mathew, 1988:

2n = 78; Jose and Mathew, 1995: n = 30 and 2n = 60). The

chromosome length at mitotic metaphase varies gradually

from about 2.6 £gm to about 1.2 £gm. Some chromosomes

appear to have centromeres at median and submedian

positions, but other centromere positions are uncertain.

Satellites were observed at the distal regions of short arms

of two submedian centromeric chromosomes (see arrows

in Figure 3C).

4.

Acmella paniculata (Wall. ex DC.) R. K. Jansen, Syst.

Bot. Monogr. 8. 67. 1985; Peng et al., Fl. Taiwan 2nd ed.

4: 814, pl. 376, photo 406 (right). 1998; Peng & Chung

in Yang et al., Manuals Taiwan Vas. Pl. 4: 220, fig. 237,

photo 405 (right) 1999.¡XSpilanthes paniculata Wall.

ex DC., Prodr. (DC.) 5: 625. 1836; Koster & Philipson,

Blumea 6: 350. 1950; Hara, J. Jap. Bot. 26: 236. 1951;

Kitamura, Acta Phytotax. Geobot. 24: 11. 1969; Chen,

Fl. Reip. Pop. Sin. 75: 359, pl. 61, f. 1-2. 1979.¡X

Spilanthes acmella var. paniculata (Wall. ex DC.) C. B.

Clarke ex Hook. f., Fl. Brit. India 3: 307. 1881.ª÷¶s¦©

Figures 1I, 1Jd

Spilanthes acmella auct. non (L.) Murray: Henry, Trans.

Asiat. Soc. Jap. 24: suppl.: 54. 1896, ¡¥acinella L.¡¦;

Hayata, J. Coll. Sci. Imp. Univ. Tokyo 18: 20. 1904;

CHUNG et al. ¡X

Acmella

(Asteraceae) in Taiwan

79

Kitamura, Acta Phytotax. Geobot. 10: 32. 1941; Li, Fl.

Taiwan 4: 495. 1978, pro parte excl. Kao s.n. 1962, pl.

1256.

Annual herbs up to 30 cm tall. Stems branched, erect

or ascending, green to purple, glabrous to sparsely pilose.

Petioles 0.4-4 cm long, narrowly winged, sparsely to

moderately pilose; leaf blades narrowly ovate to ovate,

1.8-6.3 ¡Ñ 0.7-4 cm, apex acute to acuminate, margins

dentate to coarsely dentate, sparsely ciliate, base attenuate,

glabrous to sparsely strigose or pilose on both sides.

Peduncles 2.2-16 cm long, sparsely pilose. Capitula

discoid, solitary, terminal, conical, 8.4-12.5 mm high,

6.9-10 mm in diameter; involucral bracts 9-12, biseriate,

margins sinuate to irregularly dentate, sparsely to

moderately ciliate, outer series 4-5, narrowly to broadly

ovate, 3-5.5 ¡Ñ 1.6-3.1 mm, inner series 4-7, lanceolate

to ovate, 3-5.5 ¡Ñ 1.2-2.6 mm; receptacles 5-8 mm high,

1.1-3 mm in diameter, apex acuminate; palea stramineous,

3.3-5.1 ¡Ñ 0.6-1 mm; disc florets ca. 100-200, bisexual,

yellow, corollas 4 or 5-merous, 1.4-2.2 mm long, tube

0.3-0.6 mm long, throat 1-1.6 mm long, lobes 0.3-0.4 ¡Ñ

0.2-0.4 mm. Achenes dark brown, 2.2-2.9 ¡Ñ 0.8-1 mm,

cork-like margins evident, without shoulders, margins

moderately ciliate with straight-tipped hairs, surfaces

sparsely to densely tuberculate, pappus of 2 subequal

bristles, longer bristle 0.5-1.1 long, shorter bristle 0.4-0.9

mm long.

Specimens examined. Taipei Co.: Wulai Township, 16

Oct 1932, S. Sasaki s.n. (TAI). Ilan Co.: nanhutashan, 6

Nov 1972, M.-T. Kao 6415 (TAI). Taichung City: Nantun

District, 15 Mar 2007, K.-F. Chung 1715 (HAST), C.-M.

Wang 9775 (TnM). nantou Co.: Yuchi Township, Sun

Moon Lake, Lalu, 21 Sep 1929, Y. Kudo & S. Suzuki 15582

(TAI), Lienhuachi, 30 Dec 1925, S. Sasaki s.n. (TAI).

Chiayi Co.: Alishan Township, 9 Oct 1906, T. Kawakami

& U. Mori 1771 (TI). Kaohsiung Co.: Alian Township,

Takangshan, 10 Mar 1987, M.-T. Kao 10466 (TAI), 14

Nov 1937, A. Moriya 2372 (TAI, TI); Chishan Township,

Oct 1905, G. Nakahara 584 (TI), Nov 1907, T. Kawakami

& U. Mori 5549 (TAI), 10 Nov 1907, S. Sasaki s.n. (TAI);

Liouguei Township, 19 Jul 1938, S. Okamoto s.n. (KYO),

12 Dec 1937, S. Okamoto s.n. (KYO). Pingtung Co.: 5

Dec 1915, E. Matuda 1867 (TAI); Wanluan Township,

Bankinsing, A. Henry 812 (MO), U. Faurie 944 (KYO);

Hengchuen Township, Kenting National Park, Oluanpi,

A. Henry 219 (MO), Kueitsuchi, 30 Dec 1928, Y. Kudo

& S. Suzuki 15901 (TAI), 1 Feb 1985, S.-Y. Lu 15230

(TAIF). Hualien Co.: Fengbin Township, 27 Mar 1930, Y.

Yamamoto 1317 (TAI); Juisui Township, Chimei, 27 Dec

1930, Y. Yamamoto 2539 (TAI). Taitung Co.: 1 Aug 1931,

Y. Yamamoto 2589 (TAI); Luyeh Township, 9 Dec 1899,

K. Miyake s.n. (TI); Lanyu, 19 Sep 1974, M.-T. Kao 8728

(TAI), Wananchao-Yehyin, 27 Aug 1968, C.-C. Hsu 4895

(TAI), between Hongtou Village and Yuzen Village, 9 Jun

1983, C.-I Peng 5278 (HAST), Hungtou Village, 28 Apr

1983, T. C. Huang, Yang, Kao, Chen, & Tang 9327B (TAI),

Yujen Village, 7 May 1984, C.-I Peng 6588 (HAST), 14

Apr 1985, C.-I Peng 7656 (HAST), en route from Hongtou

Village to Tienchih, 6 Apr 1987, C.-I Peng & Y.-K. Chen

10771 (HAST), Yehyin, 4 Aug 1968, Namba et al. s.n.

(TI), Hungtou village to Yehyin Village, 7 Apr 1987, H.-F.

Yen 853 (HAST), Langtao Village, 27 May 1996, T.-Y.

Yang et al. 6588 (HAST).

Distribution and Notes. Acmella paniculata i s

distributed in India, Sri Lanka, Indochina, Malaysia, the

Philippines, southern China, and Taiwan, occurring in

moist and weedy habitats from sea level to up to 2,500 m

(Jansen, 1985b). Although early collections suggest that

A. paniculata was once widespread in Taiwan (Figure 2),

more recent records stem mostly from the southeastern

part of the island, especially Lanyu Island, Taitung County.

However, Acmella paniculata has been incorrectly treated

as an alien and naturalized plant of tropical American

origin (e.g., Liu and Ou, 1981; Wu et al., 2004; Wu and

Huang, 2005), an error that probably resulted from Li¡¦s

confusion of this species with A. oleracea (Li, 1978).

Acmella paniculata can be easily recognized by its discoid

capitula (without ray florets; see the color photographs in

Peng et al., 1998, and Peng and Chung, 1999) and ciliated

achenes with evident cork-like margin. In central Taiwan,

it was found to have been cultivated for decades by a local

farmer as a means of curing toothache and a substitute for

A. oleracea (pers. obser., K.-F. Chung, in 2007).

Chromosome cytology. The somatic chromosome

number and chromosome morphology at mitotic

metaphase of this species are reported here for the first

time. The chromosome number 2n = 52 (Figure 3D) was

observed for a plant collected in Taichung City (Chung

1715, HAST). This number is concordant with the meiotic

count of n = 26 for a plant collected in Lanyu Island,

Taitung County (Peng 5278, HAST), in a report prepared

by Ching-I Peng and published in Jansen (1985a). The

chromosome length at mitotic metaphase varies gradually

from about 2.3 £gm to about 1.2 £gm. Some chromosomes

appear to have centromeres at median and submedian

positions, but other centromere positions are uncertain.

Satellites were not observed.

5.

Acmella uliginosa (Sw.) Cass., Dict. Sci. nat. (ed.2) 24:

331. 1822; Jansen, Syst. Bot. Mongr. 8: 55. 1985; Chung

et al. Taiwania 52: 276, fig. 1-2. 2007.¡XSpilanthes

uliginosa Sw., Prodr. (Swartz) 110. 1788. ªh¥Íª÷¶s¦©

Figures 1C, 1I, 1Je

Spilanthes iabadicensis A. H. Moore, Proc. Amer. Acad.

Arts 42: 542. 1907; Koster & Philipson, Blumea 6: 351.

1950; Hara, J. Jap. Bot. 26. 236. 1951; Grierson, Rev.

Handb. Fl. Ceylon 1: 221. 1980; Koyama, Fl. Jap. IIIb.

32. 1995.

Spilanthes acmella auct. non (L.) Murray: Thrower, Hong

Kong Herb. 2. 105. 1987.

Annual herbs. Plants 10-30 (-50) cm tall. Stems one

to several from base, erect to ascending or occasionally

decumbent, green to purple, glabrous to moderately pilose.

80

Botanical Studies, Vol. 49, 2008

Petioles 0.5-1.5 cm long, sparsely to moderately pilose,

wingless or narrowly winged; leaf blades lanceolate,

narrowly ovate or ovate, 1.3-5 ¡Ñ 0.3-2.5 cm, apex acute

to acuminate, margins sinuate to dentate, sparsely ciliate,

base attenuate to cuneate, glabrous to sparse pilose on

both surfaces. Peduncles 1.2-3 cm long, sparsely pilose.

Capitula radiate, solitary or 2 or 3, terminal, ovoid, 5-8

mm high, 4-6 mm in diameter; involucral bracts 5 or 6,

uniseriate, narrowly to broadly ovate, 2-4 ¡Ñ 0.5-2 mm,

sparsely to moderately ciliate; receptacle 3-6 mm high,

0.5-1 mm in diameter; palea stramineous or sometimes

with a purple-red tinge in the early flowering stage,

2.5-3.5 ¡Ñ 0.5 mm; ray florets 4-7, bisexual, corollas

yellow to orange-yellow, 1.5-3.5 mm long, tube 0.5-1.5

mm long, limb trifid, 1-2 mm long, 0.5-1.5 mm wide;

disc florets 68-148, bisexual, yellow to orange yellow,

4-merous, corolla 1-1.6 mm long, tube 0.2-0.5 mm long,

throat 0.7-1.2 mm long, lobe triangular, 0.2-0.3 ¡Ñ ca.

0.2 mm. Achenes black, 1.2-1.8 mm long, 0.4-0.6 mm

wide, moderately to densely ciliate with straight-tipped

hairs; pappus pale brown, of 2 sub- or unequal bristles,

longer bristle 0.2-0.7 mm long, shorter 0.1-0.5 mm long.

Phenology: flowering throughout the year in Taiwan.

Specimens examined. Keelung City: 30 Oct 1993,

T.-C. Chung s.n. (HAST). Taipei City: Beitou District,

Guandu Nature Park, 9 Mar 2007, C.-M. Wang 9698

(TnM); nangang District, Academia Sinica, 27 Jan 2005,

C.-I Peng 20234 (HAST), 12 Dec 2006, C.-I Peng & K.-F

Chung 21013 (HAST), 29 Mar 2007, C.-M. Wang & C.-Y.

Li 9906 (TNM); Zhongshan District, Dajia Riverside

Park, 18 Dec 2004, M.-J. Jung w121802 (TnM), w121806

(TAIF), 21 Mar 2007, C.-I Huang & K.-F. Chung 3092

(HAST). Taipei Co.: Banciao City, 26 Jun 2007, C.-I

Huang & K. F. Chung 3210 (HAST); Tucheng City, 1

Jul 2007, C.-I Peng 21146 (HAST). Taoyuan Co.: Jung-

Li City, 5 Apr 2007, K.-F. Chung 1717 (HAST); Kuanyin

Township, Hsinpo, 10 Jan 2001, C.-I Peng 17230 (HAST).

Taichung City: Nantun District, 15 Mar 2007, K.-F. Chung

1713 (HAST), C.-M. Wang 9771 (TnM). nantou Co.:

Mingjiang Township, Chieh-Yuan Herb garden, 29 Mar

2007, C.-I Huang et al. 3104 (HAST).

Distribution and Notes. Native to tropical regions

in Africa, America, and Asia, Acmella uliginosa is now

widely naturalized and has become invasive in the wet and

disturbed habitats of the Pacific islands (e.g., Fuji Islands),

New Caledonia, the Ryukyu Islands (as Spilanthes

iabadicensis, Koyama, 1995), the Philippines, and Hong

Kong (Jansen, 1985b; Thrower, 1987, as Spilanthes

acmella). Recently Chung et al. (2007) reported the

naturalization of this species in Taipei, northern Taiwan. In

addition to the collections cited in Chung et al. (2007), a

comprehensive survey of herbarium specimens in Taiwan

indicate that the earliest known record of A. uliginosa in

Taiwan was in 1993 (T.-C. Chung s.n., HAST) in Keelung

City, northern Taiwan. Subsequently it was found with

increasing frequencies in the damp paddy fields, disturbed

areas, and roadsides of northern and central Taiwan (Figure

2). On the campus of Academia Sinica, A. uliginosa has

become one of the most dominant species around the man-

made ecological Pond. Such dominance was also observed

in an abandoned paddy field in Taichung City (pers.

observ., Chung, in 2007). Color photographs of Acmella

uliginosa are also commonly seen through a Google search

to the traditional Chinese webpages. In Taiwan Acmella

uliginosa can be distinguished from congeners by its

smaller, radiate capitula and the smaller (1.2-1.8 mm long)

and ciliated achenes. In recent fieldtrips, we also found the

naturalization of this species in southern China (Yunnan,

Pingbian, Peng et al. 18710, HAST; Yingjiang, Peng et al.

19052, HAST) and Vietnam (Yen Minh District, Du gia

Community, Peng et al. 20166, HAST).

Chromosome cytology. The somatic chromosome

number and chromosome morphology at mitotic

metaphase of this species are reported here for the first

time. The chromosome number 2n = 52 (Figure 3E) was

observed for a plant collected on the campus of Academia

Sinica, Taipei City ( Peng & Chung 21013, HAST). This

number is concordant with the previous reported meiotic

chromosome number of n = 26 for plants collected from

Trinidad (Jansen, 1985a). The chromosome length at

mitotic metaphase varies gradually from about 2.0 £gm

to about 1.0 £gm. Some chromosomes appear to have

centromeres at median and submedian positions, but

other centromere positions are uncertain. Satellites were

observed in the distal regions of the long arms of two

median centromeric chromosomes (shown by arrows in

Figure 3E).

Acknowledgements. We thank Nicholas Hind and David

E. Boufford for critical comments on the manuscript;

Robert K. Jansen for identifying Acmella uliginosa; Kuo-

Hsuan Hsu, Wen-Chih Lin, and Ming-Jer Jung for guiding

us to localities of Acmella brachyglossa and A. ciliata;

Chieh-I Huang and Chieh-Hua Liu for helping with the

fieldwork; Ming-Chao Yu for technical support; and Shan-

Hua Wu for helpful discussion regarding the invasiveness

of Asteraceae in Taiwan.

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