Taxonomic Studies in Desmodium heterocarpon (L.) DC. (Leguminosae)

12 Pages·1991·1.4 MB·English

by  Hiroyoshi Ohashi

植物研究雑誌
J. Jpn. Bot.
66: 14-25 (1991)
Taxonomic Studies in Desmodium heterocarpon (L.) DC.
(Leguminosae)
Hiroyoshi OHASHI
Biological Institute，Fa culty of Science，T ohoku University，S endai，9 80 JAPAN
Dωmodium heterocarpon (L.) DC.の分類学的問題
大橋広好
東北大学理学部生物学教室 980仙台市青葉区荒巻字青葉
(Received on October 2，1 990)
Seven items of taxonomic and nomenclatural problems in Desmodium heterocaψon (L.) DC. are
studied and the following conclusions are obtained. 1) D. toppinii is identical with D. heterocarpon
var. heterocarpon. 2) D. heterocarpon subsp. angustifolium is an ew subspecific name for D. retiω，latum.
3) D. polycarpum var. rigidum is as ynonym of D. heterocarpon subsp. angustifolium. 4) D. heterocarpon
subsp. angustifolium f. pilosum is adi stinct form. 5) D. heterocarpon var. heterocarpon f.αlbiflorum
is aw hite flowered form. 6) D. heterocarpon subsp. ovalifolium is newly recognized at the subspecific
rank. 7) A key to all the infraspecific taxa of D. heterocarpon is prepared.
Desmodium heterocarpon (L.) DC. is distri- described on the basis of specimens from Ceylon
buted in tropical，su btropical and warm regions in collected by Hermann in Burmann in Thesaurus
Southeast & East Asia，In dia，Pa cific islands and Zeylanicus 117，t. 53，f. 1(1 737). It was transferred
Australia. This species has been known as D. by De Candolle (1825) to Desmodium as D.
heterocarpum since De Candolle (1825)，b ut the heterocarpum (L.) DC.，a nd he circumscribed this
correct specific epithet is heterocarpon based on species with elliptic，o btuse and glabrous leaflets
Hedysarum heterocarpon L. (Van Meeuwen 1961). and erect pods. The second species that is recog-
The species is common on sunny roadsides or in nized later to be simi1ar to D. heterocarpon was
grasslands and along or in thickets or forests. It described by Burman f. (1768) as Hedysarum
belongs to the section Nicolsonia of the subgenus siliquosum，a nd the third was by Poiret (1805) as
Sagotia and one of the most highly polymorphic Hedysarum polycarpum. These two were trans-
species in the genus in Asia (Ohashi 1973，1 990). ferred by DeC andolle (1825) to Desmodium，.i e.，
Desmodium heterocarpon has been variously D. siliquosum (Burm.f.) DC. and D. polycarpum
de1imited by many taxonomists. Hedysarum (Poir.) DC.，re spectively. The fourth species similar
heterocarpon L.，p ublished in Sp. Pl. 747 (1753) to D. heterocarpon was D. trichocaulum DC.
with such an important character of the species as collected by Wallich in Nepal. This species was put
‘floribus spicatis' for the section Nicolsonia，wa s by DeC andolle (1825) in ap osition rather remote
-14ー
February 1991 Journal of Japanese Botany Vol. 66 No. 1 15
from D. heterocarpum，b ut Baker (1876) recog- genera Desmodium and its allies. These are re-
nized it as D. polycarpum var. trichocaulon (DC.) garded later by Van Meeuwen (1961) and by
Baker，t hough this variety，a ccording to Baker's Ohashi (1973) to be identical with D.heterocarpon
description，s eems to be very close to D. hetero- or to be members of D.heterocarpon group. They
carponv紅 .strigosum Van Meeuwen. Succeedingly are D. heteroClαrpum，D. siliquosum，D. ovalifolium，
many species similar to D. heterocarpon have been D.reticulatum，D . birmanicum，a nd D.toppinii.
described from Southeast Asia. Schindler's delimitation of D.heterocarpon is，
Schindler (1928) recognized six species to be therefore，ve ry narrow. However，in local floras
distinct in his monographic bibliography of the in Asia D.buergeri or D.polycarpum，w hich were
Fig. 1. An isosyntype of D回'fflodiumbuergeri in K.
16 植物研究雑誌第66巻第1号 平成3年2月
included as synonyms of D.heterocarpum by occurs in Burma，T hailand，C ambodge，L aos，
Schindler (1928)，ha d been treated as distinct from Vietnam，a nd China. On the other hand，a f orm
D. heterocarpon. Desmodium buergeri (Fig. 1)， with inflorescence-rachides densely covered with
which was described on the basis of specimens appressed straight hairs widely occurs within the
collected in Japan，ha s often been recognized to ranges of the typical form of which inflorescence-
be distinct in Japan. rachides ecovered with spreading hooked hairs，
町
Van恥feeuwen(1961)，ho wever，e xpanded the though both forms have somewhat different ranges
species boundary of D. heterocarpon by the inclu- in distribution and are usually not growing side by
sion of D. siliquosum and D. ovalifolium. Ohashi side. Biosystematic investigations of D. hetero-
(1973) accepted her concept and expanded it in- carpon such as that done by Schultze-Kraft and
corporating in D.heterocarpon two more species， Benavides (1988) are necessary to understand
i.e.，D .birmanicum and D.reticulatum. This polymorphic natur ofthis species in local popula-
邸
concept (Ohashi 1973) becomes the broadest for tions of various localities in the Asiatic regions.
D. heterocarpon， but fundamental characters In the present paper seven items of taxonomic
circumscribing the species are almost the same as and nomenclatural problems in D. heterocarpon
those of De Candolle (1825) and Ohashi (1973). are treated mainly after examination of herbarium
Desmodium heterocarpon is characterized by specimens in A &G H，B M，E ，K ，L ，P ，T A I，TI ，
Ohashi (1973) as having 1-3-foliolate glabrous and TUS. Also，1 h ave observed variation in living
leaves，p rincipally elliptic or ovate or obovate material担Nepalin 1977，Ta iwan in 1982，'8 4 and
terminal leaflets，u sually retuse or obtuse at the '88 and in Yunnan，C hina，in 1984.
apex，lo nger inflorescences (usually 3-13 cm long) 1w ould like to thank those herbaria for the use
and erect or ascending pods with 4-8 articles of of their facilities and for making material available
transverse-oblong or -obovate (shorter than 4.5 for study. 1w ould also like to thank Dr. R.
mml ong and less than twice as long as broad) Schultze-Kraft of Centro International de
within the section Nicolsonia that includes 12 Agricultura Tropica (CIAT)，C olombia，f or in
剛
species in Asia (Ohashi 1973). Such diversity of formation relating to variation of living material
opinions on the species concep臼 ofD. hetero- of D. heterocarpon in Southeastern Asia and
carpon is caused by the reason that whole ranges supplying many specimens of his Desmodium
of the variation of this species have hardly been collection to our herbarium (TUS). Also，1 a m
recognized. deeply indebted to Dr. J. F. Veldkamp of the
Desmodium heterocαrpon includes several Rijksherbarium，L eiden，f or reading the manu-
，
forms in Southeast Asia that are considered to be script of this paper and making valuable sugges-
differentiated from the typical form by af ew tions for its improvement.
morphological characters. They occur in narrow 1) Desmodium toppinii and D. heterocarpon
areas or in wide ranges. For example，a f orm with Desmodium toppinii Schindler and D. hetero-
glabrous pods is known only from Ceylon and carpon (L.) DC. edistinguished by the size of
訂
South India，a nd that with long fruit-pedicels th位 podsand terminalleaflets，an d by the relative
(7-10 mml ong) and lax-flowered inflorescences size between terminal and lateralleaflets (Ohashi
from Burma and Thailand. A characteristic form 1973). Among specimens from Indo-China kept in
having narrow leaflets and long inflorescences P (photo in TUS) there are forms intermediate
February 1991 Journal of Japanese Botany Vol. 66 No. 1 17
between these two species，f or example Poilane follows:
14485 from Vietnam and Poilane 28495 from “Dωmodium polycarpum DC. v angustifolia
紅 .
Laos. 恥10reover，variation ranges in these Benth. MSS.
characters show wider ranges than previously Chiengmai，in eng jungle on Doi Sootep，6 00
observed in D. heterocarpon，a nd the differences m. Kerr 772. Dist. Tavoy (Wall. Cat. 5729K in
between both are continuous. The former species， Herb. Kew)."
therefore，b ecomes as ynonym of the latter. The specimen Kerr 772 (Fig. 2) is in Kew and
Desmodium heterocarpon (L.) DC.，P rodr. 2: is definitely referable to the subsp. angustifolium.
337 (1825)，ut heterocarpum; Ohashi in Ginkgoana This was republished in his paper in the Aberdeen
1: 210 (1973). University Studies 57: 59 (1912)，bu t without any
Hedysarum heterocarpon L.， Sp. P .1747 (1753). changes from the original publication. Hence，th e
Type: Ceylon. Herb. Hermann 2: 32，3: 39 &4 :20 name is a“nomen nudum" and cannot serve as
(BM，sy ntypes: designated by Schubert in F .1Trop. ab asionym of Desmodium heterocarpon subsp.
E. Afr. Leg. Pap. 462，19 71). αngustifolium (Craib) Ohashi. The combination at
subsp. heterocarpon v紅.heterocarpon: Oh郎副， the subspecific rank using Craib's varietal epithet，
1. c. 213 (1973). however，is valid. Since no valid names were
D. toppinii Schindler in Fedde，R ep. 21: 5 available at the rank of subspecies，t he Craib's
(1925); Ohashi， .1 c. 226，p 1. 33a，fi gs. 67-3 (pod) epithet，αngustifolium，w as chosen as an ew name
& 64-11 (seed) (1973)，s yn. nov. Type: Burma， on the basis of the Article 72 of the International
Wasi，al t. 7000ft. S.M. Toppin 4048 (CAL，ho lo.; Code of Botanical Nomenclature，1 988.
E，is oふ Theea rliest valid n forthis plant at the rank
田町
Description of leaves and pods of D. hetero- of species is D. reticulatum Champ. ex Bentham.
αcrpon (emending that of Oh.ashi， .1 c.): Leaves 3，・ In the original publication of this species，B entham
1&3 orl-foliolate; leaflets 1.5-12 cm long， (1852) noted as“A single specimen gathered in
・ ・
1-5 cm wide，l ateral leaflets smaller than or Hong-Kong，w ithout any note of the precise
nearly equal to the terminal ones，0 .8-10 cm locality." There are，h owever，t wo sheets of the
long，0 .5-4 cm wide. Pods sessile，i ndehiscent same collection in Kew; one is from the Bentham
and separating at the joint of articles or sometimes Herbarium and the other from the Hooker
dehiscent along the lower suture，na rrowly oblong， Herbarium. The sheet of the Bentham Herbarium
1.5-2.8 cm long，2 .5-4.5 mmw ide，w ith 4-8 is naturally considered to be the holotype of this
articles; articles quadrate or broadly oblong， combination (Fig. 3).
2.5-4.5 mml ong，2 -4.5 mmw ide. Desmodium heterocarpon (L.) DC.
2) Correction of nomenclature of Desmodium subsp. angustifolium Ohashi in Ginkgoana 1:
heterocarpon subsp. angustifolium Ohashi and tbe 212 (1973)，n om. nov.
type of D. reticulatum A new combination D. reticulatum Champ. ex Benth. in Hook.，
Desmodium heterocarpon subsp. angustifolium Kew Joum. 4: 46 (1852). Benth.，F l. Hongk. 84
(Craib) Ohashi was made on the basis of D. (1861). Gagnep.，F l. Gen. Indoch. 2: 585 (1920).
polycarpum DC. var. angustifolium Craib. Craib，F l. Siam. Enum. 1: 415 (1928). Merr. &
However，t he variety has no description. It was Chun in Sunyatsenia 2: 248 (1935). Chun &C hang，
published by Craib in Kew Bulletin 1911: 38 as Fl. Hainan. 2: 275 (1965). Type: Hong Kong.
18 植物研究雑誌第66巻第l号 平成3年2月
Fig. 2. The specimen，K err 772 (K)， that wωcited by Craib under Desmodium polycarpum DC. var.
angustifo，UαBenth.
February 1991 Journal of Japanese Botany Vol. 66 No. 1 19
Fig. 3. The holotype of Desmodium reticulatum Champ. ex Benth. (Champion 254，t he right，K ).
There are two specimens on one sheet; the right holotype and the left Weight 128.
20 植物研究雑誌第66巻第1号 平成3年2月
Champion 254 (l三holo.[Herb. Benth.]，is o.凹erb. Hitam. Of these specimens the first one is chosen
Hook.]). as the lectotype of the variety.
Meibomia reticulata (Champ. ex Benth.) O. Desmodium heterocarpon subsp. angustifolium
Kuntze，R ev. Gen. 1: 198 (1891). Ohashi.
Desmodium polycarpum DC. var. D. polycarpum var. rigidum Ridley in Journ.
angustifolium Craib in Kew Bull. 1911: 38 (1911)， Str. Br. Roy. As. Soc. 59: 97 (1911); Fl. Malay
nom. nud. Pen. 1: 609 (1922). Lectotype: Peninsular
D. polycarpum var. rigidum Ridley in Jou rn. Malaysia: Kedah，A lor Sta. Ridley 15147 (K).
Str. Br. Roy. As. Soc. 59: 97 (1911)，s yn. nov. 4) The taxonomic position of Desmodium
Desmodium heterocarpon subsp.αngustifolium reticulatum var. pilosum Craib Desmodium
Ohashi is characterized as follows: The stems reticulatum var. pilosum Craib is characterized by
pubescent or sometimes pubescent mixed with Craib as吐lespreading long hairs on the stem and
minute hooked hairs (less than 0.5 mml ong) branches give the plant a very different
especially on the upper parts. Leaves 子foliolateor appearance'. It was treated as as ynonym of D.
sometimes 1-foliolate in the lower parts of the heterocarpon subsp. angustifolium Ohashi in
stem; terminalleaflets narrowly ovate，la nceolate Ginkgoana 1: 213 (1973)，bu t the form is distinct
or narrowly oblong，a cute or obtuse at apex， from the typical form.
2.5-8.5 cm long，0 .8-3 cm wide，3 -6.5 times as D. heterocarpon (L.) DC. subsp. angustifolium
long as wide，gl abrous or sometimes with minute Ohashi
hooked hairs (less than 0.1 mmlo ng) and/or with f. pilosum (Craib) Ohashi，c omb. et stat. nov.
straight hairs (about 0.5 mmlo ng). 1nflorescences D. reticulαtum var. pilosum Craib，F l. Siam.
10-30 cm long，s carcely branched. Calyxes Enum. 1: 416 (1928). Type: Siam. Doi Sutep，op en
1.2-1.6 mml ong，4 -10bed，t he lowest lobes grassy forest，ca . 1350 m. A.F.G. Kerr 1308 (K，
longest. Pods erect or sometimes ascending，ne ither holo.).
deflexed nor spreading. Seeds obliquely rectan- 5) A white flowered form of Desmodium
gular，a bout 1.8x 1. 5m m，r eddish brown. heterocarpon
Distribution: Burma， Thailand，P eninsular Desmodium heterocarpon (L.) DC. subsp.
Malaysia，1 ndo-China，a nd China. heterocarpon var. heterocarpon f. albiflorum
Habitat: 1n forests .，along roadsides，a nd in (Ridley) Ohashi，c omb. et stat. nov.
open places. D. polycarpum var. albiflorum Ridley，F l.
3) Identity of Desmodium polycarpum var. Malay Pen. 1: 609 (1922).
rigidum Ridley Desmodium polycarpum var. 6) Taxonomic status of Desmodium ovalifolium
rigidum Ridley，t hat has been neglected in the Desmodium ovalifolium had been separated
recent treatments of the genus or in floras，is from D. heteroCiαrpon (or D. polycarpum) by
identical with D. heterocarpon subsp. Wallich (1831-32)，M errill (1910)，G agnepain
angustifolium Ohashi as listed in the synonyms of (1920)，R idley (1922)，a nd others，w hile Van
the subspecies mentioned above. Three specimens Meeuwen (1961)，Ba cker &B akh. f. (1963)，Oh ashi
were cited under this variety in the original descrip- (1973)，et c. regarded both species as identical. A
tion. They are Ridley 1514え Curtiss. n. from note by Ridley (1922)，“This (=D. ovalifolium)
Lankawi，a nd Curtis 459 from Penang，A yer has been confused by most botanists with D.
February 1991 Journal of Japanese Botany Vol. 66 No. 1 21
polycarpum，t hough in life the two could not be Catalogue，th e Wallich no. 5730 is described as “?
mistaken. It differs in i臼 creepinghabit，r ound BT avoy W.G.". However，tw o kinds oflabels are
silky leaves and pale lavender flowers"，co uld not attached on 5730b sheet (Fig. 4). No. 5730a
be confirmed on herbarium specimens except for σig. 3) was∞llected by Wallich in 1822 in Pen g，
組
the shape and hairiness of leaves. Characters in血e Malaya. One of the two labels attached on the
leaves of D. ovalifolium are，un fortunately，co n- 5730b on the right hand is Tavoy (2 Oct. 1827，no .
tinuous with those of D. heterocarpon. 350) and the other on the left hand is Kilaben (8
Recently Desmodium ovalifolium was studied Oct. 1827，no . 388) (Fig. 4). Both collections of
by Rugayah (1986，'8 7) and by Schultze闇Kraftand 5730b are made by W. Gomez in and near
Benavides (1988). Rugayah stated that some Tenasserium，B urma.
differences are present in morphological and Desmodium heterocarpon subsp. ovalifolium
anatomical characters between var. heterocarpon (Prain) Ohashi，c omb. nov.
and var. ovalifolium in flowers，le aflets，ep idermal D. polycarpum DC. var. ovalifolium Prain
cells and stomata. According to Schultze-Kraft and in Joum. Asiat. Soc. Beng. 66(2): 141 (1897).
Benavides，w ho have observed this species and D. D. ovalifolium Wallich [Cat. no. 5730
heterocarpon in more than 300 different popula- (1831-32)，n om. nud.; Prain，.I c.] ex Merr. in
tions not only in their natural habitat in SE Asia Philip. Journ. Sci. Bot. 5: 85 (1910). Gagnep. in
but also under experimental field conditions in Fl. Gen. Indoch. 2: 587 (1920). The specific com-
Colombia，D. ovalifolium is ap rostrate，st rongly bination，D. ovalifolium，w as validated by Merrill
stoloniferous and mat-forming herb or subshrub (1910).
with l-foliolate leaves when young and 1-and D. heterocarpon subsp. heterocαrpon var.
3-foliolate when mature，t he leaflets somewhat ovalifolium何Tall.ex Prain) Rugayah in Rein-
coriaceous，lu strous and without any markings on wardtia 10: 382 (1987).
the upper surfaces，wi th compact inflorescences， Distr.: Thailand，C ambodia，L aos，V ietnam，
and with densely pubescent pods. These features Malay Peninsula，Su matra，Bo rneo，Ce lebes，Ja va，
shows clear differences from typical D. hetero- and the Philippines.
carpon (SchultzeKraftand Benavides，1. c.). 7) Key to the infraspecific taxa A key to the
・
Desmodium heterocarpon is polymorphic，bu t infraspecific taxa of Desmodium heterocarpon is
the form referrable to D. ovalifolium， in prepared by revision of myp revious key (Ohashi
most cases，ca n be recognized by the combination 1973) with addition of several new treatments
of those morphological characters. The problem mentioned in this paper.
is the presence of forms intermediate between both， 1. Terminal leaflets narrowly ovate，a cute or
but，a ccording to Schultze-Kraft & Benavides， obtuse at apex，3- 6.5 times longer than broad.
natural hybrids between them are produced. I Inflorescences 10-30 cm long，n ot branched
think，t herefore，t hat D. ovalifolium is better .s ubsp. angustifolium
recognized as as ubspecies of D. heterocarpon. 2. Stems and branches with appressed hairs
There are three collections under Wallich no. .f. angustifolium
5730 in the Wallich Herbarium of Kew，of which 2. Stems and branches with spreading long hairs
one is mounted on one sheet，57 30a，an d other two f. pilosum
are on one sheet，57 30b. According to the Wa11ich's 1. Terminalleaflets otherwise，us ually obtuse or
22 植物研究雑誌第66巻第1号 平成3年2月
Fig. 4. The specimen，W allich 5730a (K)， one of the two on which the name Desmodium ovalifolium
Wallich is based.
February 1991 Journal of Japanese Botany Vol. 66 No. 1 23
噌今〉 手
Fig. 5. The specimen，W allich 5730b (K)，l abeled as Tavoy (right) and as Kilaben (le白).These were
col1ected by W. Gomez. One of the two on which the name Desmodium ovalifolium Wallich is based.