387 
the name of Leptoderris. The fruit is that of Derris and the 
name refers to this fact and to the circumstance that the genus has 
narrow petals and calyces. 
This being a natural and uniform genus as regards the floral and 
(where known) the fruiting characters, some light is thrown upon 
the value for purposes of generic segregation, in this part of the 
Natural Order, of other characters, such as the presence or absence 
of stipellae and of callosities or auricles at the base of the standard. 
Both these characters vary considerably in this genus, being in 
fact, only of importance in distinguishing small groups of species, 
and appear to be here only of secondary taxonomic importance. 
All the species inhabit Western Tropical Africa, with the excep- 
tion of L. Kirkii and L. Harmsiana which come from the eastern 
region and L. calva which is a native of Uganda. 
By the courtesy of the Director of the Royal Botanic Gardens, 
Kew, this paper has been prepared in the Kew Herbarium and the 
Leptoderris, Dunn, gen. nov. [Leguminosae-Dalbergeae] ; affinis 
Derrei, Lour., sed floribus dense nodoso-racemosis, calyce anguste 
campanulato, vexillo angusto, cymbiformi, haud reflexo differt. 
Calyx anguste campanulatus, sericeus, dentibus brevibus 4, uno 
bidentulato. Petala glabra. Vezillum anguste oblongum, cymbi- 
forme, erectum vel patens, rigidum, laminae basi plana vel calloso- 
auriculata. -Alae oblique oblongae, carinae supra unguem leviter 
adhaerentes. Carina parum incurva, petalis dorso cohaerentibus. 
Stamina monadelpha, vexillari basi caeteris soluto autem vexilli 
mgui plus minusve adhaerente. Antherae versatiles. Ovarium 
1-(vel 2) planocompressa. : 
Frutices scandentes vel raro erecti. Folia alterna imparipinnata ; 
foliolis oppositis saepe retusis. Flores in ramis paniculae dense 
nodoso-racemosi. Bracteae parvae caducae ; bracteolae ovatae vel 
subulatae, parvae. 
Species 14, Africae tropicae incolae. 
CLAVIS SPECIERUM. 
Foliola matura subtus sericea vel saltem in venis tomentosa 
Foliola subtus adpresse argenteo-sericea ... 1, L. hypargyrea. 
Foliola subtus tomentosa ‘ saute 
Foliola supra opaca, membranacea, non reticulata 
le oe 2. L. brachyptera. 
Foliola supra nitentia, coriacea vel chartacea, infra reticulata — 
Foliola subsessilia aa a 7 ee a. de Croetzet. 
Foliolorum petioluli 4 mm. se iy oe 
omentum calycis paniculaeque longum squarrosum : 
eg ee. ; 4, LL. Kirkit. 
t- 
