Proc. Indian Acad. Sci. (Plant Sci.), Vol. 93, No. 2, June 1984, pp. 165-177 Printed in India.

Taxonomy of Bidens section Psilocarpaea (Asteraceae-Heliantheae- Coreopsidinae) in India

K M M DAKSHINI and PRITHIPALSINGH Department of Botany, University of Delhi, Delhi 110007, India MS rr16216213 Dr162 1983; revised 7 February 1984

Abstract. Critiealexamination ofnumerous spr showed that Bidens sect. Psiloearpaea is represented in India only by B. pilosa var. ~ minor (BI.) Sherffand B. bipinnata Linn. The occurrenceofB. biternata (Lour.) Merr. & Sherffas suggestedearlier could not be established during the presr taxonomic investigation on the genus Bidens in India.

Keywords. Bidens; taxonomy; Psilocarpaea.

1. Introduction

Delimitation of taxonomic categories is primarily based on the correct appreciation of discontinuities in character va¡ and/or in patterns of geographical distribution. In stable taxa these requisites are generally fulfilled and the taxonomic units are easily de¡ On the other hand taxonomic groups in which phenotypic variability and limited gene exchange exist pose a serious difliculty to the taxonomists. The genus Bidens Linn. belongs to this category (Gillett 1975; Gillett and Lim 1970; Mensch and Gillett 1972; Grierson 1972; Sherff 1937; Weedon et al 1974; Wild 1967). Although only three species of Bidens section Psilocarpaea (characterised by long slender cypselae narrowed from the middle to the top) namely B. pilosa L., B. bipinnata L., and B. biternata (Lour.) Merr. & Sherff have been reported to occur in India, their taxonomic treatments have varied from time to time, and the understanding of their circumscription is still disputed. According to some authors (Chavan and Oza 1961, 1966; Maheshwa¡ 1963; Oomachan and Billore 1969; Rao and Joseph 1965; Rau 1968; Santapau 1953; Saldanha and Nicolson 1976), Bidens biternata (Lour.) Merr. & Sherff is the most common representative of this group, the Linnean B. pilosa is either absent or very rare and B. bipinnata L. is infrequent in its distribution. However, Babu (1977) reported that B. pilosa L. and B. bipinnata L. are frequently dist¡ in the Northwest Himalaya, and remarked that B. biternata "may occur within this area as a weed'. A similar observation on the distribution of B. pilosa L. in S. India was made by Matthew (1981). A comparative analysis of the taxonomic treatments in these floristic accounts clearly demonstrates that the problems related to the identification of these taxa have been largely due to the use of leaf morphology as the main taxonomic character (Babu 1977; Chavan and Oza 1961). In a taxonomic investigation such characters do not generaUy help in identification of a large number of specimens and the discontinuities are not appreciated. Further, the taxonomic distinctness of these three species has been influenced by the views on the synonyms assigned to each taxon. The following brief resum› of the 165 166 K M M Dakshini and Prithipalsingh available literature illustrates the various views on the circumscription and delimi- tation of taxa within the section Psilocarpaea. Clarke (1876) listed Bidens pilosa L. and B. decomposita DC. in his 'Compositae Indicae'. Hooker (1882) segregated B. pilosa L. into three varieties, B. pilosa var. 1 pilosa proper, var. 2 bipinnata, and var. 3 decomposita. Additionally, in his notes Hooker (1882) listed Bidens wallichi DC. as a synonym of B. pilosa var. 2 bipinnata. Duthie (1903) recognised only B. pilosc L. and listed B. bipinnata (i.e.B. pilosa var. 2 bipinnata sensu Hooker) as its synonym. Cooke (1906) considered Hooker's var. 2 bipinnata as 'scarcely worth distinction' in the Bombay Presidency, and thus recognised only B. pilosa L. as the common Indian member of the genus Bidens. Collett (1921), on the other hand, recognised B. pilosa L. and B. wallichi DC. as distinct species, thus not following Hooker (1882) who considered the latter as a synonym of B. pilosa var. 2 bipinnata. Sherff (1937) in his monograph on the genus Bidens pointed out the erroneous treatment by Hooker (1882) of B. bipinnata asa variety of B. pilosa and instead established B. bipinnata L. asa distinct species with the following names as its synonyms: B. pilosa var. 2 bipinnata (L.) Hook.; B. pilosa var. 3 decomposita (Wall. ex DC.) Hook.; and B. decomposita Wall. ex DC. Sherff (1937) also removed B. wallichi DC. from the synonymy of B. pilosa var. 2 bipinnata of Hooker, and considered it as conspecific to Bidens biternata (Lour.) Merr. & Sherff. Further, in his notes under B. bipinnata (Sherff 1937 p. 372) and B. biternata (Sherff 1937 p. 399) he commented that due to the superficially intermediate leaves, 'B. biternata (= B. wallichi DC.), a species very common in British East India', was erroneously equated by Hooker with B. bipinnata. Santapau (1953) overlooked 'British East India' in the above statement of Sherff (1937) and remarked: 'This (i.e. Bidens biternata) is the plant known to the w¡ of the Indian Floras as B. pilosa. Sherff in his recent monograph on the genus Bidens has shown that the common Indian plant is not the Linnean plant. Subsequently ali the floristic accounts published by Indian taxonomists dealt with B. biternata (Lour.) Merr. & Sherff as the common Indian Bidens with B. pilosa auct. non Linn. as its synonym (Chavan and Oza 1961, 1966; Maheshwari 1963; Oomachan and Billore 1969; Rao and Joseph 1965; Rau 1968; Saldanha and Nicolson 1976). In recent years some taxonomists who regard the common Indian plantas Bidens biternata (Lour.) Merr. & Sherff also reported the occurrence of the Linnean B. pilosa as a rare plant from several parts of the country (Chavan and Oza 1961, 1966; Oomachan and Billore 1969; Panigrahi et al 1964; Saldanha and Nicolson 1976; Santapau 1961). Bidens bipinnata L. has also been reported asa new record from different parts of the country (Babu 1977; Chavan and Oza 1966; Dakshini and Prithipalsingh 1971; Raizada 1976; Saldanha and Nicolson 1976). Thus the taxonomy and nomenclature of B. pilosa, B. bipinnata, and B. biternata in our country are in a confusing state. There is an important need to clear this confusion especially because these taxa forma weedy community. The present paper deals with the taxonomy and nomenclature of Bidens section Psilocarpaea in India.

2. Materials and methods

Following the suggestion that 'species and lower taxa should be formulated around natural populations' (Davis and Heywood 1967), plants were sampled from natural populations ofBidens taxa from different regions of India. These plants were examined Taxonomy of Bidens 167 to establish the extent of variation in vegetative (particularly leaf morphology) and floral (capitulum morphology, organisation, phyllaries, cypselae, etc) characters. These studies were supplemented with a critical examination of herbarium specimens available in the major Indian herbaria, and also ofphotographs ofauthentic specimens located at Kew, Gray, Field Museum of Natural History, and British Museum (Natural History) herbaria. We have followed Sherff (1937) for typification of relevent taxa and location of type specimens.

3. Resuits and discussion

The specimens examined fall in two distinct groups. The characters studied in detail and the range of variation in these characters are summarised in table 1. Leaf morphology is highly variable (Figures 1-6). Even within these two groups different patterns could be identified based on the degree of dissection of the lamina and the shape of ultimate segments. It is amply clear from these data that such va¡ vegetative characters overlook discontinuities in more stable reproductive characters. It is prima¡ due to the reliance on leaf morphology that there has been an erroneous identification of the Bidens taxa by earlier workers. However, our observations show that it is easy to establish the range of distinct discontinuities in the characters of flowering and fruiting capitula and more particularly on the cypselar morphology, and thus highlight the use of these characters for the delimitation of Bidens species. A similar suggestion for delimiting the species ofsection Psilocarpaea was made by Sherff (1937) who emphasised the importance of the morphology of involucral bracts, number of total and ligulate florets per capitulum, cypselae morphology, and number of awns per cypsela. Unfortunately these suggestions did not influence a majority of Indian taxonomists. Similar to Sherff's (1937) observations, we have also found that the monomorphic cypselae is a very important feature for distinguishing Bidenspilosa L. from B. bipinnata L. and B. biternata (Lour.) Merr. & Sherff. The iatter two species have dimorphic cypselae within a single capitulum. Of these, B. biternata has glabrous outer cypselae and hispid (but not tuberculate-hispid) inner ones, while in B. bipinnata the outer cypselae are tuberculate-hispid and the inner ones are sparsely hairy in the upper-half and glabrous in the lower-half. In the Indian B. pilosa L. all the cypselae in a capitulum are linear-curved, black, and tuberculate-hispid either apically or thorough- out their length. Similarly, in B. bipinnata Las represented in India, the dimorphic cypselae within a single capitulum are all linear, but differ in their size, colour and surface patterns. The outer cypselae which are tuberculate-hispid are generally brown in colour, but sometimes they may be hispid only and then blackish-brown. The inner ones are black and generally glabrous throughout their length or occasionally very sparsely hairy only in the apical region. Recognising that variation in cypselar morphology is an important character for identification, and on the basis ofa correlative assessment ofcharacters listed in table 1 and taking the data presented by Sherff(table 2) into account, the two groups ofplants commonly occurring in India conform to (i) B. pilosa var. fl rainor (BI.) Sherff (group I plants in table 1) and (ii) B. bipinnata L. (group II plants in table 1). Contrary to earlier observations, none of the material now examined could be assigned to B. biternata (Lour.) Merr & Sherff as defined by Sherff (1937). In fact, the present observations support Sherff's comments regarding this taxon as 'a species very common in British 168 K M M Dakshini and Prithipalsingh

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Figures 1--6. Photographs of herba¡ speeimens showing different leal" patterns observedin Bidenspilosa var. ~ minor (BI.) Sherff 1. Aogarwa110649 (DUH),2. Paniorahi and Afora 8919 (SSA);3. Agoarwa16678 (DtJH)and Bidens bipinnata Linn. 4. Irani NI 4604 (BI.AT); 5. Prithipalsingh 10027 (DUH); 6. Aggarwal 10001 (DUH);(see text for explanations).

East India'. This region comprised only a very small portion of the North-east part of the present Republic of India but was mainly referable to other contiguous North- eastern regions such as Burma and the Malaysian peninsula. It may also be pointed out that this region formed part of the tract extending upto Canton-China, the type locality of Coreopsis biternata Lour. (the basionym of Bidens biternata). However, since this species has been reported to occur west of India also, further studies and collections are needed to document the occurrence and distribution of this species in India. Taxonomy of Bidens 171

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Thus Bidens pilosa var fl minor (BI.) Sherff and B. bipinnata L. are the commonly distributed taxa throughout India. The occurrence of B. biternata (Lour.) Merr & Sherff, as suggested earlier by many Indian taxonomists has not been substantiated. To facilitate easy identification of these species of Bidens in India, a key to the species and diagnostic characters along with the specimens examined are provided below.

4. Key to the species

A. Ligule white B. Outer involucral bracts linear; cypselae dimorphic (outer glabrous, inner hispid); usually 4 (rarely 3 or 5) aristate ...... B. biternata BB. Outer involucral bracts spathulate; cypselae monomorphic, tuberculate-hispid; usually 2 or 3 aristate ...... B. pilosa var. [3 minor AA. Ligules yellow; cypselae dimorphic (outer tuberculate-hispid, inner sparsely hairy to glabrous) ...... B. bipinnata

5. Taxonomic enumeration

5.1 Bidens pilosa var. [3 minor (BI.)Sherff, Bot. Gaz. 80 387 1925 Sherff, FieM Mus. Nat. Hist. Bot. Vol. XVI, 421-429, 1937. Herbs. Annual to biennial. Erect to decumbent. Decumbent stems when in contact with soil often root at the nodes. Stem 4-angular, longitudinally ribbed; nodes and younger parts glabrous to pilose. Leaf petiolate; lamina entire to pinnatisect into 3 or 5 segments; segments orate to elliptic- lanceolate, acute to apiculate at apex, margins serrate, serra ciliate, surface, glabrous to pilose. Capitulum heterogamous, radiate, involucral bracts 2-seriate; outer spathulate, connate at the base, pubescent; inner lanceolate, glabrous to pubescent, margin hyaline. Receptacle paleaceous; palea linear-lanceolate, narrower than inner in- volucral bracts. Ray florets ligulate; ligules white; sterile. Disc florets tubular; yellow; bisexual. Cypselae all of one kind (monomorphic), linear-curved; black; tuberculate- hispid either apically or throughout; with 2 or 3 (rarely 4) retrorsely barbed apical awns (aristae) (figure 7). Common in moist and shady disturbed habitats, cultivated areas, and gardens. Flowering and fruiting profuse after monsoon. A very widely naturalised weed in warm parts of the world.

Specimens examined

Acland A CK 1307, locality not mentioned, 1926 (BLAT); A99arwal 6601, 6602, 6605, 6614, 6615, 6638, Delhi, 1973 (DUH); idem 6622, 6625, 15811, 15812, Nainital, 1975 (DUH); idem 6644-48 (5 sheets), Kodaikanal, 1975 (DUH); Ÿ 10604-615 (12 sheets), Kotagiri, 1975 (DUH); idem 10616-625 (10 sheets), Coonoor, 1975 (DUH); idem 10626- 652 (27 sheets), Bangalore, 1975 (DUH); idem 10656-658, Hassan, 1975 (DUH); anon 15140 (det. J K Maheshwari), Kameng Frontier Division, 1958 (ASSAM); anon s.n. (LWG, acc. No. 49052); Asrava RA 3136, Dangs, Gujarat, 1956 (BLAT); Balakrishnan 50132, Ioski, Khasi & Jaintia Hills, 1969 (ASSAM);Barnes s.n., Bill Hills (DD, acc. No. 10999); Bhattacharyya 17562, Mirzapur, 1961 (BSA); Bole 727, Girnar Hill, 1952 Taxonomy of Bidens 173

Figures 7-9. General morphological features of 7. Bidens pilosa var. fl minor (Bi.) Sherff from Aggarwa16602 (DUH); 8. Bidens bipinnata Linn. from Aggarwal 10001 (DUH) in India; 9. Bidens biternata ('Lour.) Merr. & Sherff (adapted from Sherff 1937) A. ( x 0-35) habit of plant; B~F ( x ca 3.04) B. Disc floret; C. ligulate floret; D. outer involucral bract; E. inner involucral bract; F. palea.; CrH. ( x ca 2-45) G. outer cypsela; H. inner cypsela. 174 K M M Dakshini and Prithipalsingh

(BLAr); idem 788, 800, Saurashtra, 1952 (Bt~T); idem 1444, North Kanara, 1955 (BLXT); Bor's collector 142, Gangtok (Sikkim), 1945 (DD); Carter 41423, Shillong, 1915 (CAL); Dakshini 7234, Mothronwala Swamp Forest, Dehra Dun (BSD); idem 13752-755 (4 sheets), Bhopal, 1976 (DUH); R. N. Dave's collection (Santapau 14396), locality not mentioned, 1951 (Bt~T); Raro Dayal 2556, Dehra Dun, 1967 (DO); Deb 30327, Kottayam District, Kerala, 1968 (MH); idem 30545, Lushai Hills, 1963 (ASSAM); Divakar PD 288, Karanja, 1959 (BLAT); idem PD 1093, Mora, 1960 (SLAT); idem PD 1262, Yova, 1960 (BLAT);Fischer 1207, Coimbatore, 1906 (CAL); Henry ANH 181, 1036, Madras, 1960 (Bt~,T); Hooper & Ramaswami 38411, Tinnevelly District, 1913 (CAL); Irani NI 5525, Matheran, 1960 (BLAW);Lace 1159, Paunda, 1891 (DD); Janaki Ammal s.n., locality not mentioned, 1955 (aSA); Jain & Bhardwaja 22597, Malabar, 1951 (DO); Kamlesh s.n., Meerut, 1959 (LWO, acc. No. 44566); Maheshwari 122, Delhi, 1954 (DUH); Majumdar 10370, Udaipur, 1966 (BSA); Mathur s.n., Solan, 1938 (OD, acc. No. 78076); Misra 5333, Allahabad, 1963 (RSA); Moonz 1821, Kardhana, Orissa, 1941 (DO); Mukerjee 5728, Tista River, Bengal, 1963 (CAL); Matthew KMM 1581, Shembagnur, 1960 (atar); Naithani3544, Dehra Dun, 1972 (DD); idem 1895, Dehra Dun, 1973 (DD); Nelson 164 K, Kurseong, 1914 (DD); Nilhata N 780, Madhurai, 1955 (BLAT); Pandey 219, Kathmandu (Nepal), 1952 (DO); Panigrahi 6156, Kameng Frontier Division, 1957 (ASSAM);idem 19447, Subansiri Forest Division, 1959 (ASSAM);idem 5536, Kainur Hills, 1962 (BSA); idem 3091, Katra (uP), 1964 (ma); idem 4047, Katwa, 1965 (BSA); idem 12600, Mirzapur, 1969 (BSA); idem 12090, Mirzapur, 1970 (BSA); idem 15283, Amarkantak, Bilaspur, M.P., 1972 (BSA); Panigrahi & Arora 8919, Bilaspur, 1964 (BSA); idem 8874, Bilaspur, 1965 (nsA); Pani#rahi & Prasad 2691, Pipri (uP), 1964 (nsA); Patels.n., locality not mentioned, 1882 (Bt~T); Prithipalsin#h 2317, Delhi, 1968 (DUa); idem 10034, 10047, 10048, Delhi, 1969 (DUa); idem 10110, 10111, 10123, 10124, Bangalore, 1970 (DUH); idem s.n., Hassan, 1970 (DUH); idem 3342, 3349, Bangalore, 1971 (DUH); idem 2742, 2753, 10195, Delhi, 1971 (DURO; Ra#hvendra s.n., Delhi, 1957 (OUH); Rajagopa16152, Allahabad, 1964 (BSA); Raizada 21193, Junagadh (Saurashtra), 1953 (aD); Raizada's collectors, Sethi & Negi 26046, Coimbatore, 1958 (aD); Randeria AR 550, Borivli, 1953 (BLAT); R S Rao 1578, NEFA, 1955 (ASSAM); idem 7377, Kameng Frontier Division, 1959 (ASSAM);Subba Rao 24779, Subansiri Frontier Division, 1961 (ASSA~t); idem 29718, Pottangi (Orissa), 1962 (ASSAM); Sahni 24138, Tehri Garhwai, 1955 (DD); Santapau 7060, Borivli, 1945 (Bt~T); idem 12665, Mahbaleshwar, .1951 (BI.Ar); idem 16001, Powai, 1953 (~LAT); idem 17355, Dangs, 1953 (BLAT); idem s.n. Castle Rock, 1953 (nt~T); idem 19369, Dangs, 1954 (BLAr); idem 20793, 20794, 21509, Vizag., 1956 (BLAT); Ram Saran s.n., Saharanpur, 1956 (LWG, acc. No. 44526); Saxena 380, 1057, Rajpur (Dehra Dun), 1960 (aD.); Ÿ 1275, Mussoorie, 1960 (aD); Sebastine 2094, Nilgiri District, 1957 (Mg); Sengupta 16599, Raigarh, 1971 (BSA); Sharma 16815, Nongpoh, Khasi & Jaintia Hills, 1938 (ASSAM);Sharma 393, Nasirabad Ghati (AJ~ER), 1958 (DO); S. K. Sharma 15813-15834, Darjeeling, 1976 (DUH); Shetty 11905, Nilgiri District, 1961 (Mr0; Schallert 8237, Florida (usa), 1958 (BLAT);Shah 4900, Malad, 1955 (BLAT); idem 7317, 7318, Madh Island, 1956 (BLAT); idem 9116, Malad 1957 (BLAT); Shenoy KVS 657, Mumbra, 1953 (BLAT); idem 4282, Mumbra, 1954 (nt~r); Srinivasan & Singh 62537, Darjeeling, 1959 (LWG); Subramanyam 8201, Madurai District 1959 (MH); Subramaniam 755, Vellapatti, 1963 (DD); Vaid & Thapliyal 25182, Darjeeling, 1958 (Da); Yerma 43768, 46336, 46675, North Lakhimpur, Assam, 1960 (ASSAM); Wagh SKW 2853, Vizag., 1956 (BLAr); idem 4704, Orissa, 1957 (BLAT); idem 5588, Tirumalai, Chittoor, 1957 (BLAT); idem 6378, Horsely Hills, Chittoor, 1957 (BLAT); Ÿ 8216, Tirumalai Hills, Chittoor, 1958 (BLAT). Taxonomy of Bidens 175

5.2 Bidens bipinnata Linn. Sp. PI. 832. 1753; Sherff, FieM Mus. Nat. Hist. Bot. Vol. XVI, 366-373, 1937. Erect annual herbs. Stem 4-angular, longitudinally ribbed; nodes sparsely to densely pilose. Leaf petiolate; lamina pinnatisect, 5-, or 7-, or 9- segmented to bipinnatifid; segments ovate-lanceolate to linear, acute, margin serrate, serra ciliate; surfaces pilose (more on the veins). Capitulum heterogamous, radiate. Involucral bracts 2-seriate; outer linear, connate at the base, pubeseent; inner ones lanceolate, margin hyaline. Receptacle paleaceous; palea linear-lanceolate, narrower than inner involucral bracts. Ray florets ligulate; ligule yellow; sterile. Dise florets tubular, yellow, bisexual. Cypselae in a capitulum of two kinds (dimorphic) aU linear but different in size, colour and surface patterns; outer cypselae generally brown and tuberculate-hispid apically, or blackish-brown and with a hairy (not tuberculate) surface; inner ones black and generally glabrous throughout their length or occasionally very sparsely hairy only in the apical region; with 3 (sometimes 2 or 4 also) retrorsely barbed apical awns (aristae) (figure 8). The Indian material falls in typical B. bipinnata Linn. Distribution cosmopolitan: in diverse habitats ranging from moist shady areas to dry rocky situations; flowering and fruiting from June to November.

Specimens examined

Aggarwa16603, 6606, 6613, 6618, 6631, Gurgaon, 1973 (DUH); idem 6607, 6608, 6617, 6619, Delhi, 1973 (DnU); idem 10001, 10002, 10007, 10661, Gurgaon, 1974 (DHU); idem 6621, 6623, 6626--6629, Nainital, 1975 (DUn); Ÿ 13701, 13705-13749 (47 sheets), Pachmarhi, 1975 (DUH); anon s.n., Poona, 1892 (aLAT, presented by Bombay Natural History Society); anon s.n., Purva, 1912 (LWG, acc. No. 795); anon 14258, Bombay, 1917 (BLAT); Arora 5595, Mhow, 1964 (BSA); Bole 412, Mahbaleshwar, 1951 (BLAT); Rara Daya12556, Dehra Dun, 1967 (DD); Garada 21816, Poona, 1902 (BLAT); Hooker s.n., Sikkim, nodate (CAL); Irani NI 4604, Matheran, 1959 (aLAr); idem N1 5462, Matheran, 1960 (BLAT); Joseph 11258, Hoshangabad, 1960 (BSA); Kanjilal 6096 (2 sheets), Barnihat, 1915 (ASSAM,DD); Mathur s.n., Solan, 1938 (DD); Mazumdar 12495, Udaipur, 1968 (BSA); idem I3208,Kota, 1968 (BSA); Menon 15801-15804, 6610, 6612, 8821, 8822 (8 sheets), Dalhousie, 1976 (DUH); Merchant 216, Matheran, 1957 (BLAT); Narayanswami 601, Godavari District, 1920 (CAL); Neelam 8820, Mussoori, 1975 (DUH); Osmaston 1386, Dehra Dun, 1928 (DD); Panigrahi 11556, Kotai Reserve Forest, 1957 (ASSAM); idem 11800, Dharampur (Bihar), 1957 (ASSAM);idem 19695, Subansiri Forest Division, 1959 (ASSAM); idem 20652, Borasamsar (Orissa), 1959 (ASSAM); idem 6080, Shivpuri, 1962 (BSA); idem 4047, Mirzapur, 1965 (aSA); Dr Prain's Collector, Hock 12, Naga Hills, 1898 (CAL); Dr Prain's Collector, Naskar 10, Baidyanath (Bengal), 1902 (CAL); Prithipalsingh 2497, 7065, 10017, 10018, 10022-10027 (10 sheets), Delhi, 1969 (DUH); idem 10143, 10144, Siliserh (Alwar), 1970 (DUH); R. S. Rao 1349, N.E.F.A., 1955 (ASSAM);Santapau 4909, Salsette, 1944 (BLAT); idem 5022, Khandala, 1944 (BLAT); idem 11183, Salsette, 1950 (BLAT); idem 11326, Purandhar, 1950 (BLAT); idem 13598, Rajkot, 1951 (BLAT);idem 16189, Saurashtra, 1953 (BLAT); idem 16667, Okha, 1953 (BLAT); idem 19923, Dangs, 1954 (BLAT); idem 21397, Jeypore (Orissa), 1956 (BLAT); Saxena 1386, Dehra Dun, 1960 (DD); S K Sharma 8824, Simla, 1975 (DUH); Shenoy KVS 1027, Matheran, 1953 (BLAT); idem KI/S 4082, Matheran, 1954 (BLAT); Tavakari T 1797,

(Ptant Sci.)-- 8 176 K M M Dakshini and Prithipalsinoh

Goregaon, 1958 (aLAr); idem T 2033, Poona, 1958 (atar); Verma 772, Kishangang (Rajasthan), 1963 (BSA); Ÿ 46413, North Lakhimpur (ASSAM); 1966 (ASSAM); Wadhwa 7428, Jhalawar (Rajasthan), 1964 (BSA).

5.3 Bidens biternata (Lour.) Merr. & Sherff in Sherff, Bot. Gaz. 88 293 1929; Sherff, FieM Mus. Nat. Hist. Bot. Vol. XVI 388--405 1937. During the present investigation, no specimen could be assigned to this species and consequently no emended description was possible. However, for its identification, it has been keyed on the basis ofcharacters described by Sherff(1937) as well as on the relevant (Sherff 1937) illustration (figure 9). It may also be mentioned that Sherff(loc. cit.) listed 17 specimens ofthis species collected from India, but all these specimens are located in herbaria outside India and these could not be examined.

Acknowledgements

The authors are indebted to Prof V H Heywood (University of Reading, ta<) and to Mt B L Burtt (Royal Botanic Garden, Edinburgh, UK) for discussion on the taxonomy of the genus Bidens and for their valuable comments. Thanks ate extended to Dr C R Babu for helpful suggestions. Their sincere thanks to the Officers of the Botanical Survey of India, Forest Research Institute, National Botanical Research Institute, and the Blatter Herbarium (St. Xavier's CoUege, Bombay), for the loan of herbarium specimens for study. The supply of photographs of authentic specimens from the Kew, Gray, Field Museum of Natural History, and British Museum (Natural History) herbaria is gratefully acknowledged.

References

Babu C R 1977 Herbaceousflora of Dehra Dun. (New Delhi: Publications and Information Directorate, CSIR) Chavan A R and Oza G M 1961 The identity of the genus Bidens of Bombay. The Linnean plant from Pavagarh; Ind~ For. 87 25 l Chavan A R and Oza G M 1966 The Flora ofPaoagarh (Baroda: M.S. University Press) Clarke C B 1876 Compositae Indicae: Descriptae et secus Genera Benthami Ordinatae. (Calcutta: Thacker Spink and Co.) Collett E A 1921 Flora Simlensis: A handbook offlowering plants of Simla and the neiffhbourhood. (Calcutta: Thacker Spink and Co.) Cooke T 1906 The Flora ofPresidency ofBombay (reprinted ed) (Calcutta: Botanical Survey of India) Vol II Dakshini K M M and P¡ 1971 Bidensbipinnata (Asteraceae) in Northern India; Proc. 58th Ind~ Sci. Congr. Part III, Abstract. 436 Davis P H and Heywood V H 1967 Principles ofangiosperm taxonomy (reprinted edn) (Edinburgh and London: Oliver and Boyd) Duthie J F 1903 Flora of the upper gangetic plains and of the adjacent siwalik and sub-Himalayan tracts (reprinted edn) (Calcutta: Botanical Survey of India) Vol I Gillett G W 1975 The diversity and history of Polynesian Bidens section Campylotheca. Harold L. Lyon Arborctum Lecture No. 6 Univ. Harvard Gillett G W and Lim E K S 1970 An experimental study of the genus Bidens (Asteraceae) in the Hawaiian Islands; Unir. Calif. Publ. Bot. 56 1-63 Grierson A J C 1972 Critical notes on the Compositae of Ceylon. Ceylon J. Sci. 10 42-60 Hooker J D 1882 Theflora of British India. (Oxford: L. Rer and Co.) Vol lII Maheshwa¡ J K 1963 Flora ofDelhi (New Dr CSIR) Taxonomy of Bidens 177

Matthew K M 1981 The Flora of Tamilnadu Carnatic. Material$ for a Flora of the 7"amilnadu Carnatic. (Tiruchirapalli: The Rapinat Herbarium, St. Josr Coilegc) Vol I Mr J A and Gillett G W 1972 The experimental verification of natural hybridization betw~n two laxa of Hawaiian Bidens (Asteraccae)~ Brittonia 24 54-70 Oomachan M and Billorr K V 1969 Asteracr162of Bhopal, A systematic study; Bull. BOl. Surv. India 11 35-40 Panigrahi G, Chowdhary S, Raju D C S and Deka G K 1964 A contribution to the botany of Orissa; Bull. Bol. Surv. India 6 237-266 Raizada M B 1976 Supplement to Duthie's flora of the upper oangetic plain and of the adjacent Siwalik and Sub-Himalayan Tracts. Dehra Dun Rajan S S 1975 Ray reduction and evolution in Bidenspilosa Linn. Proc. 62nd lndian Sci. Conor. Part III, Abstract 67 Rao R S and Josr J 1965 Obsr on the flora of $iang Frontier Division, NEFA; Bull. Bol. Surv. India 7 138-161 Rau M A 1968 Flora of uppr gan8etic plains and of the adjacent Siwalik and sub-himalayan tracts: Check List; Bull. Bot. Surv. India 10 suppl 2 Saldanha C J and Nicolson D H 1976 Flora ofHassan district, Karnataka, India. (New Delhi: Amr Publishing Co. Pvt. Ltd.) Santapau H 1953 The Flora of Khandala on the western ghats of India; Rec. Bol. Surv. India 8 1-151 Santapau H 1961 Critical notes on the idr and nomenclaturr of some Indian plants; Bull. Bot. Surv. India 3 !1-21 Shr E E 1937 The Gr Bidens; Field Mus. Natl. Hist. PubL Chicago 16 1-700 Wr R R, Butlr M G, Moorr E D and Russcll K D 1974 Taxonomy of the great plains spr162 of B/dens. in IVth midwest Praire conference, Univ. North Dakota, Grand Fork. Wild H 1967 The Compositae of the flora Zambr atea I. Kirkia 6 1-62