«04 



Leguminosae 



Desmodium 



Desmodium rotundifolium 



o ~m 



Map 1237 

 Desmodium sessihfolium (Torr.) T. & G. 



Loment long-stalked, the stipe 2-3 times as long as the calyx. 



Peduncles arising from the base of the stem, much longer than the leafy stem; 



leaflets short-acute or obtuse 3. D. nudiflorum. 



Peduncles terminating the leafy stem, rarely with a few axillary racemes in 

 Des7nodium pauciflorum. 

 Plants rarely more than 4.5 dm high; leaves scattered on the stem; leaflets 

 ovate or oval, not abruptly narrowed at the apex, acute or obtuse; in- 

 florescence usually a simple raceme, rarely paniculate; flowers few, 



white 4. D. pauciflorum. 



Plants generally 5-10 dm high; leaves mostly clustered at the top of the stem 

 (or base of the peduncle), terminal leaflets large, broadly ovate, abruptly 

 contracted into a long, acuminate tip; inflorescence generally a panicle of 



racemes, rarely simple, usually many-flowered 5. D. acuminatum. 



Loment not long-stalked, the stipe less than 2-3 times as long as the calyx. 

 Lower surface of leaflets pubescent with hooked hairs; plants large. 



Segments of loments rhomboidal, the middle mature ones mostly 8-12 mm 

 long and 5-6 mm wide; leaflets ovate, blunt, firm but not coriaceous, the 



lower surface only faintly reticulated 6. D. canescens. 



Segments of loments oval, less than 6 mm long; leaflets ovate-oblong or ovate- 

 lanceolate, acute, subcoriaceous, the lower surface reticulated, the primary 



and secondary nerves prominent 7. D. illinoense. 



Lower surface of leaflets glabrous or pubescent without hooked hairs; leaflets 

 ovate, ovate-lanceolate to linear-lanceolate or oval. 

 Segments of mature loments mostly 8-12 mm long and 5-6 mm wide. 



Leaflets glabrous beneath or essentially so, not glancous beneath, long- 

 acuminate at the apex 8. D. bracteosum. 



Leaflets pubescent beneath with long, half-spreading hairs, merely acute at 



the apex 8a. D. bracteosum var. longifolium. 



Segments (middle) of loments less than 8 mm long. 



Stipe of loment as long as the calyx, generally a half longer; segments of 



loment usually 2-5; stipules and bracts deciduous. 



Leaflets of a lanceolate type (rarely a few ovate), oblong-lanceolate 



to linear-lanceolate or ovate-lanceolate, usually thin. 



Segments of loments of an oval type, strongly rounded on the ventral 



side, usually 4-5 mm long; stems more or less pubescent at least 



above 9. D. canadense. 



Segments of loments of a rhomboidal type, semi-rhomboidal on the 

 ventral side, usually 5-8 mm long. 



