PEA FAMILY 379 



lobe: plant low, 3-4 in. high, branching, from a creeping roots tock, with 

 oval petiolate leaves clustered near the tips of the stems, the lower leaves 

 scale-like: there are small, whitish and fertile (cleistogamous) flowers on the 

 rootstock. In moist, rich woodland. East and North. 



P. Senega, Linn. Seneca snakeroot. Flowers small in terminal, slender, 

 spike-like racemes: stem erect, 8-15 in., simple and leafy: leaves lanceolate, 

 alternate: flowers white or greenish, on very short pedicels; corolla with 

 small crest. Perennial. 



XXVIII. LEGUMINOS^E. Pulse, or Pea Family. 



Herbs, shrubs, or trees, mostly with pinnately compound alter- 

 nate leaves: flower papilionaceous in the species described below: 

 fruit typically a legume. A vast family and widely dispersed, with 

 many tropical species. Genera about 400, and species about 6,500. 

 By some authors, the species with papilionaceous flowers are separated 

 into the family Papilionacea?, and those of the acacia tribes, with 

 regular flowers, as the Mimosaceae. Familiar leguminous plants are 

 pea, bean, lupine, clover, alfalfa, vetch, wistaria, locust, red-bud. 



a. Shrubs, twining 1. Wisteria 



aa. Trees, or erect shrubs. 



B. Leaves once or twice pinnately compound: flowers 

 in racemes: often large trees. 

 c. Flowers truly papilionaceous, rather large and 

 showy, usually fragrant: leaves with sharp 



spines or prickles often in place of stipules 2. Robinia 



cc. Flowers small, greenish and inconspicuous, not 

 truly papilionaceous: tree usually armed with 



large pronged thorns 3. Gleditsia 



bb. Leaves simple, entire: corolla not truly papilionaceous: 



fls. in umbel-like clusters, before the leaves 4. Cercis 



aaa. Herbs. 



B. Plant climbing by tendrils. 



c. Calyx leafy -lobed 5. Pisum 



cc. Calyx not leafy-lobcd. 



D. Style flattened, bearded down 1 side 6. Lathyrus 



dd. Style slender, with a tuft of hairs at apex only, 



or about the upper part 7. Vicia 



bb. Plant not tendril-bearing: leaves compound. 



d. The leaves 3-foliolate (sometimes simple in No. 9). 

 E. Leaves digitatcly compound. 



F. Stamens diadelphous (9 and 10), and the 



flowers in heads, or spikes 8. Trifolium 



ff. Stamens 10, distinct: flowers in racemes 9. Baptisia 



