310 PROFESSOR BALFOUR ON THE 
me,—‘“ I have dissected the flower, and compared it with numerous drawings 
and descriptions of Phaseolus and Lablab, both of which genera I knew well 
in India. The flowers of your plant are, as you remark, quite phaseoloid; but 
then the seed is different from any known seed of that genus. The seed, with 
its elongated sulcated hilum, is very close to that of Mucuna, but the characters 
of the flower and pod remove it from that genus. Were the carina and pistil not 
so completely Phaseolus, it would otherwise, and especially in its nodose inflo- 
rescence, come near to Lablab. As it is, I cannot see how one can help making 
a new genus of it.”’ 
The flowers were subsequently shown by Dr ANDERSON to Mr BenTHAM, who 
is the chief authority in regard to Leguminose ; and in a subsequent letter Dr 
ANDERSON says:—“ Mr Bentuam desires me to tell you that the plant is very 
near Canavalia in the long hilum and the calyx, and very near Phaseolus in the 
flower generally, except in the stigma.” The following is the description of the 
genus. The characters are illustrated by excellent drawings (Plates XVI. and 
XVII), made, with his usual botanical accuracy, by Dr GrEvVILLE, from specimens 
and careful dissections supplied by me :— 
Nat. order, Leguminose ; Sub-order, Papilionacee; Tribe, Euphaseolew. 
PHYSOSTIGMA VENENOSUM; Ordeal Bean of Calabar. 
Gen. CHar.—Calyx campanulatus, apice quadrifidus, laciniis brevibus, lacinia 
suprema bifida. Corolla crescentiformis, papilionacea ; vexillum recurvum, apice 
bilobatum, basi angustatum, margine utroque auriculatum, membrana inflexa 
auctum, medio longitudinaliter bicallosum ; alae obovato-oblongve, liberze, supra 
carinam conniventes, versus basin appendiculatze, curve; carina vexillum zequans, 
apice rostratum, rostro multum incurvo.. Stamina decem, diadelpha, filamento 
vexillari libero, supra basin appendiculato. Discus vaginifer. Ovarium stipi- 
tatum, 2-3-ovulatum. Stylus cum carina tortus, infra stigma subtus barbatus ; 
stigma obtusum, cucullo cavo oblique tectum. Legumen dehiscens, oligospermum, 
elliptico-oblongum, subcompressum, extus rugosum, endocarpium intus tela laxa 
cellulari tectum, isthmis cellulosis inter semina. Semina strophiolata, hemis- 
pheerico-oblonga hilo late-sulcato semicincta. 
Herbee suffruticosze volubiles in Africa occidentali tropica crescentes: foliis 
pinnatim-trifoliolatis, stipellatis, floribus nodoso-racemosis, purpureis. 
P. venenosum.—The only species of the genus as yet known. 
A large twining plant, turning from right to left. 
Root spreading, with numerous fibrils, often having small succulent white 
tubers attached. Stem about two inches in diameter at its thickest part, some- 
times attaining a length of fifty feet, cylindrical, of a brown-gray colour, rough- 
ish; younger branches of a dark-green colour, thickened at the nodes ; branches 
twisting on themselves and round those in their vicinity; wood of the stem very 
porous, giving out, when cut, a pretty free stream of limpid fluid, which is 
—>E— i 
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