LEGUMINOS.E 317 



A. Shrub, twining 1. Wistaria 



AA. Herbs. 



B. Plant climbing by tendrils. 



c. Calyx leafy lobed 2. Pisum 



cc. Calyx not leafy lobed 3. Lathyrus 



BB. Plant not tendril-bearing. 



c. Leaves digitate, of 3 leaflets 4. Trifollum 



cc. Leaves pinnate (terminal one-stalked, and the stalk 

 jointed), of 3 leaflets. 



D. Flowers small, in very slender racemes 5. Melilotus 



DD. Flowers small to medium, in heads or short spikes. 6. Medicago 

 DDD. Flowers medium to large, clustered at the joints of 

 raceme. 



B. Keel of corolla coiled into a spiral 7. Phaseolus 



EE. Keel curved but not coiled 8. Vigna 



1. WISTARIA. 



Tall shrubby twiner, producing long, dense racemes of showy flowers : 

 leaves pinnate, with several or many leaflets: 2 upper calyx-teeth shorter: 

 standard large and roundish: pod knotty, several-seeded. 



W. Chinensis, DC. Wistaria. Popular climber for porches, from 

 China, with large drooping racemes of bright blue (sometimes white) pea- 

 like flowers in spring and summer. 



2. PlSUM. PEA. 



Slender herbs, climbing by tendrils which are homologous with leaflets: 

 leaves pinnate, with 1-3 pairs of foliar leaflets, and very large leafy stipules: 

 lobes of calyx leafy: flowers large, white or pink, on axillary peduncles: 

 pod a typical legume, several-seeded. 



P. sativum, Linn. Garden pea. Figs. 190, 284. Smooth and glaucous: 

 leaflets usually 2 pairs, broad-oval: peduncles 2- or more-flowered. Old 

 World. 



3. LATHYKUS. VETCHLING. 



Much like Pisum, differing chiefly in very technical characters, but best 

 told in general by the narrow leaflets and pods, and not leafy calyx. 



L. odoratus, Linn. Sweet pea. Figs. 165, 222. Annual, the stem hairy: 

 leaflets one pair, narrow-oval or oblong: flowers 2 or 3 on a long peduncle, 

 very fragrant, in many colors. Southern Europe. 



L, latifolius, Linn. Everlasting pea. Fig. 246. Perennial of long 

 duration, smooth, the stems winged: leaflets one pair, long-oval: flowers 

 many in a dense cluster on long peduncles, rose-purple and white. Europe. 



4. TEIFOLIUM. CLOVER. 



Annual or perennial herbs with digitate leaves of 3 leaflets (all 3 leaflets 

 joined directly to top of petiole): flowers small, with bristle-form calyx- 

 teeth, in dense heads: fruit a 1- to few-seeded little pod which does not 

 exceed the calyx. 



