234 Leguminaceae 
I. Peduncles usually without a bract; corolla with yellow standard and — 
white wings. W.E. (L. pinnatus.) 
L, bicolor (Doug].) 
I]. Peduncles with a bract at the umbel; corolla with yellow standard and 
purple wings. W. (L. formosissimus.) 
L. gracilis ( Benth.) 
EE. Leaflets 9—15; flowers purple. W. E. 
L. crassifolius Gr. 
Pr PSORALEA PSORALEA 
rerbs (ours) or shrubs, perennial. Leaves 1—7-foliolate (ours 3—7), punctate 
with dark glands or pellucid dots; stipules wide. Flowers blue or pink or whute, usually 
in spikes or racemes. Standard ovate or orbicular, clawed; wings oblong to falcate; keel” 
uncurved, obtuse. Stamens monadelphous or diadelphous. Ovule 1. Pod ovoid, short, ] 
indehiscent. Seed 1. (Gk. psoraleos—scurfy; referring to the glands or dots on the 

leaves. ) 
A. Leaflets broadly ovate; seed grayish. W.E. (P. melilotoides for our region.) 
F, physodes Doug. 
AA. Leaflets lanceolate; seed light brown. E. (P. lanceolata scabra; P. purshii.) 
P. lanceolata Pursh 
PETALOSTEMUM (Petalostemon, Kuhnistera) PRAIRIE CLOVER 
Herbs, mostly perennial (so ours), glandular-dotted. Leaves odd-pinnate, leaflets 
5—9 (ours); stipules setaceous, minute. Flowers bright purple, in spikes (ours) or 
heads; these dense, terminal, peduncled. Calyx 5-toothed; teeth somewhat united, nearly 
equal. Petals 5, on filiform claws; 4 of them nearly similar, their filiform claws united 
with the stamen-tube quite to the summit where they drop off by .a joint; standard free, 
inserted at the bottom of the calyx, its limb cordate or oblong. Stamens 5, monadel- 
phous; the tube cleft. Ovary with 2 ovules side by side. Pod membranous, enclosed in 
the calyx, indehiscent. Seed 1. (Gk. petalon—petal, stemon—stamen; from the union 
of the two in the flower.) E.  P. ornatus Doug]. 
ROBINIA LOCUST 
Trees (ours) or shrubs. Leaves odd-pinnate; stipules small, often spiny. Flowers 
white (ours), in axillary or terminal racemes. Calyx-teeth short, wide, the upper 2 
somewhat united. Standard large, reflexed; wings oblong, curved; keel obtuse, curved. 
Stamens diadelphous. Ovary stalked; ovules many. Pod flat, linear, 2-valved, in ours 
1—2 dm. long. (Honor of J. and V. Robin, who first cultivated the tree in: Europe. ) 
Wik: R. pseudacagia L. 
ASTRAGALUS (Phaca) RATTLE-WEED 
Herbs, erect to prostrate. Leaves odd-pinnate; leaflets entire; tendrils none; stipules 
persistent. Flowers in spikes or racemes, rarely solitary, small, narrow. Calyx 5-toothed. 
Petals with slender claws; keel obtuse. Stamens diadelphous. Stigma terminal, mi 
nue. Pod quite various, usually turgid or inflated but sometimes flat or angular, one or 
both sutures often projecting inward somewhat and sometimes dividing the pod into 2 

cells. Seeds |—many. (The Greek name of some plant of this family. ) ' 4 
A. Ped membranous, thin, often inflated. Group | (p..235) = 
