DIADELPHIA. DECANDRIA. 95 
| pressed, carinate, villous on the upper side. 
| Suture of the legume naked. 
Stem scandent or diffuse; petiole many-leaved, leaflets 
and stipules large; peduncles axillary, 1 or many-fiower- 
ed. 
Srecres. 1. P. maritinum. Abundant on the shores 
of Lakes Erie, Huron and Michigan, but differs from the 
European species in having a pubescent legume. 
Ai present there are but 4 species of this genus, indige- 
nous to Europe and Egypt, but the habitat of the garden 
pea (P. sativum) like that of many other important plants 
in human diet, appears not to have been ascertained. 
r 495. OROBUS. E. (Bitter-Vetch.) 
* Style linear. _C, ng. Calia obtuse at 
&. the base; 1 nts deeper and mostly 
shorter. — See 
| Stem herbaceous, often erect: leaves conjugate, biju- 
gate or pinnate, mostly terminated by a short and straight, 
undivided, setiform tendril; stipules mostly semisagittate; 
flowers racemose, axillary and terminal. 
Species. 1. O. * dispar. , Leaves unequally pinnate, 6 
to 8 pair, leaflets linear, obtuse; stipules simply ovate, 
‘acute; racemes sessile, filiform, 2 or 3 together; segments 
of the calix equal, the uppermost indenture deeper and 
wider. Has. On arid hills near Fort Mandan. Flowering 
in June. Ops. This and the followimg species differ very 
remarkably from the usual habit of the.genus, but analy- 
tically compared with Orebus sy'vaticus, now before: me, 
* they appear to be inseparable congeners. Root perennial. 
Stems numerous, decumbent, branched, terete below, an- _ 
eae 
| _ Vetches. The habit of this plant is more that of Astraga- 
des than Orobus, hn se 
ode * lnsiftiue. Sericeously villous; leaves termate and 
farmiy Kneasaupules undid, ovate lanceoa 
fe ee: 
