244 S. Afc. J.llot. 1998.64(4): 244- 245

A new species of Psora/ea (Leguminosae: Papilionoideae) from the ,

Charles Stirton The Herbarium, Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AB, England

Received 27 Septemher 1996: revised 27 Afarch 1998

A new species, Psoralea peratica, from the Western in South Africa is described and illustrated.

Keywords: Leguminosae: Papilionoideae, new species, Psora/ea, South Africa, Western Cape, taxonomy

Current address: The National Botanic Garden ofWa!es, Middelton Hall, Llanarthne, SA32 BHW, Wales, U.K.

Introduction Diagnostic features and affinities The genus Psuralea L. sensu slriclo (Psoraieeae, Leguminosae) Psoru/ea peratica is one of the most handsome of the psoraleas comprises 51 species and is endemic to Africa. The new species when in full bloom. This distinctive species has been confused in described below arises from a revision of the genus undertaken the past with the supposedly highly polymorphic and widespread for the Flora of Southern Africa. This paper is the fourth in a species P. aphylla L., a convenient dumping ground for all spe­ series of preliminary papers published on the genus (Stirton cies without leaves (aphyllous). Recent studies on the anatomy 1981 a, 1981 b, 1995). Terminology used to describe a, the unique of leaves (Crow, Stirton & Cutler 1997), chemistry, cupular cupular structure which subtends each flower, and b, petal sculp­ structure, scale morphology, and seedlings (Stirton, unpub!.) turing, are taken from Tucker and Stirton (199 1) and Stirton have shown clearly that aphylly has arisen more than once in the ( 1981c) respectively. genus and that it is not a good indicator of relationship. This spe­ cies is characterised by its dense erect habit with lax upper Description branches, densely velutinous branch tips and its large dark Psora/ea peratica eH. Stirt. sp. nov. Habitu denso erec­ mauve flowers clustered at the ends of short seasonal shoots. It is toque ramis superioribus laxis, apice ramulorum dense veluti­ distinguished from P. aphylla by its much larger flowers, tightly noso et floribus grandibus atromalvinis ad apicem ramulorum clustered synnflorescences, and differently shaped cupulums. brevium temporariorum aggregatis distincta. A. P. aphylla L. The specific epithet is derived from the Greek word 'm:pa floribus multo maioribus, inflorescentiis dense congestis et cupu­ nKo~' meaning 'dwelling on the other side' referring to its mar­ lis heteromorphis distinguenda. ginal distribution to the other Psoraleas common along the mountains and plains to the east of the Piketberg. TYPUS- South Africa, Western Cape, 32 18 (Clanwilliam): eastern extremity of Piketberg Mountains, Gys-se-KraaI (- DA), Geographical distribution Rourke 1863 (NBG, holotypus; NBG; K, MO isotypi). Dupli­ Psoralea peratica is endemic to the Piketberg Mountains. The cates of this collection number were distributed as Psora/ea sp.; species grows mainly along sandy seepages. so additional isotypes should, therefore, exist in other herbaria. Large shruhs or small trees lip to 5 m tall, trunk up to 150 mm in diam­ Flowering time eter. Stems 1-2, branching in upper parts; seasonal shoots pendulous, Flowering occurs between October and November. virgate, smooth. glabrous except for young tips which are densely velutinous. Leaves reduced to scales; scales 2.5- 3.0 mm long, tightly Conservation status appressed to shoot, glabrescent, swollen, densely glandular, margins This species is vulnerable and has a restricted geographical range !inely ciliate; apex acute, hard, blackish. Synjlorescences 8- 10-£1ow­ with a narrow habitat specificity. Although the fire-survival ered, terminating upper part of short seasonal shoots; uniflorescences strategy is not known, the species has all the features of other re­ 1- 2-11owered, each subtended by a scale; peduncle 2 mm long, terete, seeders in Psoralea. In 1990 it was abundant in a few local popu­ sericeous. bracts absent or small; cupulum 4 mm long, bi lobed, abax­ lations. This may have changed after the extensive fires in the ial lohe dceply cleft, ci liate, eupular braets absent or minute. F/owers Piketberg in 1993/94 after which some rare legumes were found 16--18 mm long. CaZvx 9 mm long, teeth 6 mm long, equal, carinal in abundance on the Piketberg (Rafnias and Aspalathus pendula: tooth oblong-Ianceolate, others falcate, margins ciliate, sericeous on Anonymous Referee). veins. inner face of teeth densely sericeous \\lith white and black hairs intamixcd: tube 2- 3 mm long. Standard 15-16 x 17-18 mm, claw 2 Pollination biology mm long and curved. broadly ovate, rdlexed to 140°; upper parts of Apart from visits I observed of Xylocopid bees visiting flowers, the petal dark mauve, nectar patch pale mauve outlined by a deep pur­ no other information is available on its pollinators. The flowers ple M-shaped flash: appendages (callosities) present, white. 1.0--1.5 are very sweet-smelling. mm long. free: auricles tOllching, forming a tube with the claw. Wing petals 17-18 x 7 mm. claw 4 mm long, white. ascending, adherent to Material studied ked petals ncar auricles, blade folded in upper region; SCUlpturing - 3218 (ClanwiJliam): eastern extremity of Piketberg Mountains. present. upper basal. comprising 7-10 transcostal lamellae. Keel pet­ Gys-se-Kraal (- DC), ROllrke 1863 (MO. NBG); (­ als 11 - 12 x 4 mm, apex acute with large purple patch on inner face. DC). Sfirfon 9324 (PRE), Kaptcinskloof (- DA) Pikctberg Moun­ claw 4 mm long. Androecium 11-12 mm long, sheath split adaxially, tains. Sfirfon 10058 (PRE). tenth stamcn free. fenestrate. Pistil II mm long; ovary 2 mm long, stipitate, sparsdy glandular near the apex; height of curvature of the Acknowledgements style 6 mm: stigma penicillate, capitate. Fruits and sceds unknown This research was funded as part of a broader study jointly by the (Figure I). B.A. Krukoff Trust for Legume Research, Botanical Research S. Afr. J. Bot. 1998,64(4) 245

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Figure 1 Psora/ea peratica L Habit x l ; 2. Flower x 2.8; 3. calyx x 3; 4. standard x 3: 5. standard, side view x 3; 6. wing petal x 3; 7. ked petal x 3; 8. androecium x 3; 9. pistil x 3 (Rourke /863). Del. Claire Smith.

Institute (now Nati onal Botanical Institute), Royal Botanic Gar­ minosae). 801. J. Linn. Soc. 124: 155- 182. dens Kew, and the University of Natal Research Fund (Pieterma­ STrRTON, C.H. 1981a. Studies in the Lcguminosae - Papilionoideae of ritzburg). J thank the Directors and staff of these organisations southern Africa. BOlhalia 13( 3-4): 317- 325. for their valuable help and facilities. I am grateful to Dr John STIRTON, C.H. 1981b. Psoraieeae. In : Advances in Legume Systemat­ Rourke of NBG for collecting the type material and for review­ ics, (eds.) R.M. Polhill & r.B. Raven. Part I. pp. 7 11 - 788. Royal ing the manuscript, Melanie Thomas for the Latin translation, ilotanic Gardens, Kew. Claire Smith (Linder) for the black and white illustration, and to STIRTON, C.H. 1981 c. Petal sculpturing in Papil ionoideae. In: Ihe late Ellaphie Ward-Hilhorst for painting a beautiful colour Advances in Legume Systematics, (cds.) R.M. Polhill & r .H. Raven. plate of this species (to be made available in an electronic mono­ Part 2. pp. 337-343. Royal Botanic Gardens, Kew. graph being prepared). STIRTON, C.H. 1995. A new species of Psora/ea (Leguminosae; Papil­ ionoideae) from Eastern South Afri ca. K/!\II8ull. 50: 619-622. References TUCKER, S. & STIRTON, C.H. 1991. Development of the cymose CROW, E.. STiRTON, C.H .. & CUTLER, D.F. 1997. Leaf anatomy of inflorescence, cupulum and flO\'f'er of Psora/ea pinnala (Lcgumi­ the genus Psora/eo sensu stricto (Psoraleeae, Pnpilionoideae, Legu- nosae: Papilionoidcac: PsoraJeeac). Bot. J Linn. Soc. 106: 209- 227.