Studies in the Leguminosae— Papilionoideae of southern Africa

Six African species of Psoralea are transferred to Cullen Medik.: C. biflora (Harv.) C. H. Stirton, C. holubii (Burtt Davy) C. H. Stirton, C. drupacea (Bunge) C. H. Stirton, C. jaubertiana (Fenzl) C. H. Stirton, C. obtusifolia (DC.) C. H. Stirton and C. plicata (Del.) C. H. Stirton. Psoralea patersoniae Schon\. based on an introduced garden plant is placed under synonomy of Cullen corylifolia (L.) Medik. The following new names are published: Lebeckia waltersii C. H. Stirton of subgenus Plecolobium C. H. Stirton; Bituminaria bituminosa (L.) C. H. Stirton of subgenus Bituminaria and B. acaulis (Stev.) C. H. Stirton of subgenus Christevenia Barneby ex C. H. Stirton; Rhynchosia arida C. H. Stirton; Eriosema gunniae C. H. Stirton, E. preptum C. H. Stirton and E. transvaalense C. H. Stirton. Eriosema capitatum E. Mey. is placed in synonomy with Psoralea tomentosa Thunb., but as P. tomentosa Thunb. is a later homonym of P. tomentosa Cav. it should be referred to P. sericea Poir.

African representatives o f Psoralea L. sensu Forbes (1930) should be rearranged into the genera Psoralea L., Otholobium C. H. Stirton and Cullen Medik.(Stirton, 1980).Psoralea L. emend.C. H. Stirton is now restricted to 17 Cape species.The new genus Otholobium comprises about 28 species widespread over the southern and eastern parts of southern Africa, with one species extending as far north as Kenya.New combinations will be made in Otholo bium once the complicated nomenclatural problems have been resolved.The remaining seven African species of Psoralea L. sensu Hutch, are here trans ferred to Cullen Medik.The Asian and Australasian material of Cullen, comprising over 40 species, falls outside the scope of this investigation.
•Botanical Research Institute, Department of Agriculture and Fisheries, Private Bag X101, Pretoria, 0001.

B IT U M IN A R IA Heist, ex Fabricius
Psoralea bituminosa L. and P. acaulis Stev.are two widely cultivated species of Psoralea L. sensu lato.The recent decision to confirm the subdivision o f Psoralea L. into a number o f genera (Stirton, 1980) has made it necessary to search for a generic name to accommodate them, the name Psoralea now being reserved for some 17 species of plants endemic to the southern tip o f Africa.Most authors have used Aspalthium Medik (1787) as a segregant generic name to accommodate P. bituminosa whenever it was thought to be distinct from Psoralea (e.g. Meikle 1977).According to Dandy (1967), however, the name Bituminaria Heist, ex Fabricius ( 1759) is a synonym o f Psoralea sensu lato.It predates Aspalthium and becomes available.There is however some controversy about selecting Fabricius generic names based on Heister's works.Some authors such as Holub (1970) and Rauschert (1968) consider Fabricius's generic names to be uninomials and invalidly published.Dandy (1967) R. 11: 226 (1945R. 11: 226 ( ), Eng. transl. 1971;;Davis., FI. Turkey 3: 264 (1970).Aspalthium acaulis (Stev.) Hutch., Gen. FI. PI. 1: 420 (1964).

L E B E C K IA Thunb.
For a number o f years an undescribed Cape legume has been circulating under the manuscript name ' Waltersia heleniae'.The correct generic place ment o f this undescribed species has remained unre solved ever since it was first discovered and collected by Dr I. B. Walters.It had been variously referred to Buchenroedera, Wiborgia and Lebeckia.Apart from the collections cited and the one in Dr Walters's per sonal herbarium, this species has apparently not been collected by the early collectors.This seems surpris ing considering the plant's rather distinctive features and, so, notwithstanding its localized distribution, it is to be expected that additional collections may still be found misfiled in undetermined covers among various genera.I have referred it to Lebeckia not withstanding the un-Lebeckia like presence of prom i nent involucrate stipules.The only other legume in South Africa which I know to have similar stipules is Argyrolobium involucratum.The alternative is to describe a new monotypic genus.Such an approach would be somewhat premature until Lebeckia and its segregates have been adequately revised and until more is known about this species which I am describ ing as Lebeckia waltersii.This species is easily sepa rated from all other Lebeckia species by its unique stipules and plicate pods.I am therefore establishing the subgenus Plecolobium to accommodate it.This name refers to the concertina-like pods.
Restricted to the eastern Transvaal between Pil grims Rest, Graskop, W itklip, Sudwala and Nelshoogte (Fig. 2).This species is found on undisturbed grassy plateaux.It grows commonly in association with another rare legume, Rhynchosia villosa (Meisn.)Druce.This composite group occurs to the west of the range of E. gunniae sensu stricto.Further collections from the intervening areas may enable their correct status to be decided.

This distinctive Eriosema is named in honour of
Miss Mary G unn, who was a recipient of the 1976 Bolus Medal for outstanding achievement in the field of botany by an amateur botanist (see Veld & Flora 62:30-31, 1976).Her knowledge o f botanical litera ture and plant collectors has been of great im port ance to both South African plant taxonomy and tax onomists alike.
Keel petals densely glandular.Gynoecium 6 mm long; ovary densely pubescent.Fruit 15-16 mm long, 10 mm wide, obliquely oblong with 2 mm long beak, softly yellow pubescent, glandular.Seed 5-6 mm long, 3 mm wide, chestnut brown with purple flecks.Fig. 6.This species was collected for the first time as recently as five years ago and is endemic to isolated populations in the Magoebaskloof-Haenertsberg region (Fig. 2).E .transvaalense hybridizes with E. angustifolium Schinz.It grows in open grassland and is particularly evident along firebreaks.
T r a n s v a a l .-2329(Pietersburg): near Ebenezer Dam (-D D ), Stirton 1438.2330 (Tzaneen): Magoebaskloof Hotel (-CB), Stir ton 1445.A C K N O W LED G M EN T S I should like to express my thanks to the following people.Messrs H. K. Airy-Shaw' and R. D. Meikle and Dr R. K. Brummitt, Royal Botanic Gardens, Kew, for their indispensable advice and assistance with nomenclatural problems and Dr. H. F. Glen for two o f the Latin translations.The Director, Royal Botanic Gardens, Kew, for use of the facilities of the Royal Botanic Gardens, Kew, for permission to use Kew negatives 19290 and 19292 and to Mr M. Svanderlik for taking the photographs.Dr J. H. Ross (Royal Botanic Gardens and Na tional Herbarium, Victoria); Prof. D. Isely and Dr N. Lersten (Iowa State University), M r R. Barneby (New York Botanical Garden); Prof. R. Dahlgren (Copenhagen); Mr K. H. Mattisson (Lund) and Dr R. Polhill, Dr B. Verdcourt and Mr G. L I. Lewis (Royal Botanic Gardens, Kew) for discussions and helpful criticism of the work leading up to this paper.
Table mountain sandstone conglomerate in association with Pteronia and Elytropappus.Flower ing occurs in July.
C a p e .-3319(Worcester):Worcester(-CB),Rourke1484 (K; NBG; PRE); Esterhuysen 35048 (K; BOL); Walters s.n.(NBG,   Herb.Walters).Hutchinson 253 (K) collected between Vredenburg and Hoetjies Bay may be conspecific with Lebeckia waltersii.It may even represent another species.It has overall a similar appearance to Rourke 1484 but differs in its non-conduplicate, wider leaves, more than 1-flowered inflorescence, less prominent stipule L. waltersii is an attractive shrub which, with its mass bloom of small yellow flowers, should delight gardeners.There is a very real danger however that this species may become extinct unless the citizens of Worcester, its locality, take concerted action to en sure its protection.It is limited to probably only some ± 60 individual plants divided into a few col onies(Walters, 1980, pers.comm.)PerhapsWorces ter could adopt it as their town flower?If other towns and villages throughout the country similarly adopted a rare or endangered species specific to their area much could be done to ensure the ade quate protection and propagation o f many species of plants across the length and breadth o f South Africa.