FLORA NIGRITIANA. Sit 
insertionem. brevibus acutis. Petìiot pollicares. Foliola 2 
poll. longa, 3-21 lata, basi rotundata truncata v. cuneata, 
trinervia, reticulatim venosa, pallide viridia, lateralia obliqua. 
Pedunculi 2-4-pollicares, validi, sulcati, pilis retrorsis. Flores 
brevissime pedicellati. Calyx 1 lin. longus, glaberrimus. 
Vexillum 4 lin. longum, latissimum, recurvum, pallide ro- 
seum, ungue brevissimo, lamina basi utrinque auriculata ; 
ale intensius coloratz, basi hinc auriculate. Legumen sub 
lente minutissime.puberulum, leviter curvatum, 13 poll. lon- 
gum. Semina oblonga, rufo-fusca. 
A most distinct species, of which the specimen is very im- 
perfect. 
8. Vigna Thonningii, Hook. fil.—Plectrotropis hirsuta, Schum. 
et Thonn. Beskr. p. 339.—Cape Coast and Fernando Po, 
Vogel. ; 
This answers very well to Thonning’s description of the plant 
he gathered at Aguapim. It comes very near to the American 
V. carinalis, Benth. Bot. Sulph., and like that species, the 
V. angustifolia, and some other African and Asiatic species, 
is remarkable for the much-curved oblique keel with a lateral 
Spur on one side only, on which character Schumacher and 
Thonning founded their genus Plectrotropis. Although they can 
scarcely be admitted to the generic rank thus accorded, they 
will probably be found to constitute a good sectional group in 
the now extensive genus Vigna. 
Besides the above eight species, West Tropical Africa pos- 
Sesses at least three others, viz.: V. gracilis, Hook. fil. (Do- 
lichos, Guill. et Perr.), from Senegambia; V. Nilotica, Hook. 
fil. (Dolichos, Delile), from Senegambia, Nubia and Egypt; 
and V. angustifolia, Hook. fil. (Dolichos, Vahl, Plectrotropis, 
Schum. et Thonn.), from Senegambia and Guinea. 
Of the genus Dolichos, although it be essentially African, no 
true representative appears to have been found within the West 
Tropical region, the D. nervosus, Schum. et Thonn., being 
probably the Lablab vulgaris, Savi, which is common over a 
great part of Africa, and exists in Senegambia and Guinea, either 
wild or cultivated, as well as Pachyrrhizus angulatus, Rich., 
