PEA FAMILY 525. 



keel equalling the banner. Stamens partly diadelphous, i. e., the tenth stamen 

 united ^\ith the rest at the middle, but free at the base. Legume flat, 1-2-seeded, 

 half-round, or spirally coiled, not jointed, pectinately prickly. 



1. O. Onobrychis (L.) Rydb. Perennial herb; stem erect, 3-5 dm. high; 

 leaflets 11-23, elliptic; calyx-lobes subulate, subequal; corolla rose-colored, 

 striate; wings about half as long as the banner; legmne brown, obliquely semi- 

 orbicular, keeled above, the lower suture and apex with short broad prickle- 

 points. 0, saliva Lam, Cultivated and occasionally escaped: Mont. — Colo. — 

 Utah — Ida. 



41, MEIBOMIA Heister. Tick-trefoil, Beggar's Ticks. 



Herbs (all ours), shrubs or vines. Leaves alternate, pinnately 3-folioIate, 

 rarely 1- or 5-foliolate; leaflets stipellate. Flowers perfect, in racemes or pan- 

 icles. CaljTC with bractlets at the base, campanulate; lobes unequal, the two 

 upper ones more or less united. Corolla in ours reddish purple; banner more or 

 less clawed; wings oblique, more or less coherent with the keel. Stamens mon- 

 adelphous or partly diadelphous; anthers alike. Pod divided transversely into 

 several indehiscent internodes, flat, in ours retrorsely hispid. [Desrnodium Desv.] 



Leaflets neither coriaceous nor strongly reticulate beneath. 1. M. canadensis. 



Leaflets coriaceous, strongly reticulate beneath. 2. M. illinoensis, 



l.^M, canadensis (L.) Kuntze. Stem erect, 6-20 dm. high, pubescent; 

 leaflets elliptic or oblong-lanceolate, appressed-pubescent and paler beneath, 

 hispidalous or glabrate above; flowers paniculate, 11-17 mm. long, purple; loments 

 about 2.5 cm. long; internodes 3-5, somewhat triangular, straight or nearly so 

 on the upper suture, uncinate-pubescent. Desmodium canadense (L.) DC. 

 Thickets and river banks: N.B.—N.C.—Okla.— (Black HUls) S.D.— Man. 

 Plain — SubjnonL ■ Jl-S. 



2. M. illinoensis (A. Gray) Kuntze. Stem 5-12 dm. high, uncinate- 

 pubescent; leaflets lanceolate or ovate-lanceolate, hispidulous above, cinereous 

 beneath, 2.5-9 cm. long; flowers paniculate, 6-9 mm. long, purple; loments 1-2.5 

 cm. long; internodes 3-6, oval or orbicular, densely imcinate. D. illinoense A. 

 Gray. Prairies: 111.— Kans.— S.D. Plain. Je-S. 



42. ViCIA L. Vetch, Wild Pea. 



Perennial or annual herbaceous vines. Leaves alternate, abruptly pinnate, 

 usually with tendrils or these represented by a tip. Flowers axillary, racemose 

 or sessile. Cal3'x somewhat oblique and gibbous at the base, the upper two 

 teeth shorter. Banner obovate or oblong, emarginate; wings obliquely oblong, 

 adherent to the curved keel. Stamens diadelphous (9 and 1); tube oblique at 

 the smnmit; anthers all alike. Style slender, with a tuft or ring of hairs at the 

 summit. Pod flat, dehiscent, 2-valved, few- or several-seeded. 



Racemes 3^0-flowered; flowers 1-2.5 cm. long. 



Racemes one-sided, dense. 15-40-flowered. 1. V. cracca. 



Racemes lax, 3-10-flowered. 



Leaflets linear to oblong; stipules usiially narrow, semi-sagittate and often entire. 

 Leaves decidedly pubescent, rather thick and strongly veined. 



Stem low; leaflets linear to oblong. 2. V. trifida. 



Stem tali; leaflets oblong or elliptic, only those of the lower leaves some- 

 times linear. 3. V. oregana. 

 Leaves glabrous or slightly pubescent when young. 



Leaflets elongate, narrowly linear; plant low and erect. 4. V. sparsifoUa. 

 Leaflets, at least the upper ones, oblong or linear-oblong; plant tall and 

 climbing. 5. V. dissitifolia. 



Leaflets broad; stipules broadly semi-sagittate or semi -orbicular in outline. 



sharply toothed. 

 Leaflets usually oval, thin and not strongly veined, mostly entire and acute 



or rounded at the apex. 6. V. americana. 



Leaflets obovate-cuneate, firmer and more strongly veined, truncate and 

 -^ toothed at the apex. " 7. V. pumila. 



Racemes 1-2-flowered. 



Flowers 1-1.8 cm. long, subsessile in the axils; annual. 8. V. angustifolia. 



Flowers 6-8 mm. long, on a distinct peduncle; perennial. 9. V. producta. 



