158 Mr. Bentuam on the Structure and Affinities 
than with Vicia, Centrosema, Trifolium, or others, and in other respects the 
two genera are very different. I have no perfect flowers in my specimens of 
Voandzeia, but they are not described as having the long calycine tube of 
Arachis: the fertile flowers have a calyx though they have no corolla, and the 
legume, though indehiscent from being subterraneous, has the sutures very 
prominent, and is not reticulated. The foliage, stipules, and inflorescence 
are entirely those of Phaseoleæ, to which tribe I should follow Ernest Meyer 
in referring it, although the want of the perfect flowers prevents me from 
ascertaining to which section of that tribe it approaches the nearest. Apeta- 
lous flowers are common in Phaseoleæ, as, for instance, in the genera Galactia, 
Glycine, Amphicarpæa, Neurocarpum, Centrosema, &c. 
The following are the distinctive characters I should propose for the genera 
Arachis and Stylosanthes, to which I subjoin a synopsis of the species of 
Arachis. 
Aracuis. Linn. 
Flores polygami. Floris hermaphroditi sterilis: calyx tubo longo filiformi, 
limbo subbipartito, labio superiore breviter 4-dentato, inferiore tenui 
integro. Corolla fauci calycis inserta. Vexillum suborbiculare. Ale 
oblongæ, liberæ, transversim leviter plicatæ. Carina incurva, rostrata. 
Stamina monadelpha vexillari interdum abortiente. Antheræ alternæ 
subrotunde, medifixæ ; alternæ oblonge, adnate. Ovarium intra tubum 
calycis subsessile, ninutum, 2—3-ovulatum. Stylus ad antheras attingens, 
filiformis. Stigma minutum vel nullum? Floris feminei fertilis: calyx, 
corolla et stamina nulla. Ovarium toro mox elongato reflexo rigido sti- 
pitatum, et cum eo continuum, acutum, intus uniloculare, simplici serie 
2—3-ovulatum, ovulis ovoideis anatropis. Stylus brevissimus, subnullus. 
Stigma subdilatatum, terminale. Legumen intra terram maturescens, 
oblongum, crassum, reticulatum, indehiscens, subtorulosum, 2— 3-sper- 
mum. Semina irregulariter ovoidea, cotyledonibus crassis carnosis, ra- 
dicula recta brevi. ; 
Herbæ humiles, sæpè prostrate. Folia petiolata, abrupte pinnata, ecirrhosa, 
foliolis oppositis bijugis. Stipule basi petiolo adnate, striafæ. Stipellæ 
nulle. Flores in spicam densam axillarem saepius approximati, singuli 
