LEGUMINOSJE. (PULSE FAMILY.) 99 



purple flowers ; standard shorter than the keel ; joints of the pod 3 or 4, smooth, 

 reticulated. 1J. Mountain above Willoughby Lake, Vermont, Wood. (Alle- 

 ghany Mountains, Michaux.) Also northward. 



17. DESMODIUM, DC. TICK-TREFOIL. 



Calyx usually more or less 2-lipped. Standard obovate : wings adherent to 

 the straight or straightish and usually truncate keel, by means of a little trans- 

 verse appendage on each side of the latter. Stamc'ns diadelphous, 9 & 1, or 

 monadelphous below. Pod flat, deeply lobed on the lower margin, separating 

 into few or many flat reticulated joints (mostly roughened with minute hooked 

 hairs by which they adhere to the fleece of animals or to clothing). Perennial 

 herbs, with pinnately 3-foliolate (rarely 1-foliolate) leaves, stipellate. Flowers in 

 axillary or terminal racemes, often paniclcd, and 2 or 3 from each bract, purple 

 or purplish, often taming green in withering. Stipules and bracts scale-like, 

 often striate. (Name from Seoyios, a bond or chain, from the connected joints of 

 the pods.) 



1. Pod raised on a stalk (stipe) many times longer than the slightly toothed calyx 

 and nearly as long as the pedicel, straightish on the upper margin, deeply sinuate on 

 the lower ; the 1-4 joints mostly half -obovate, concave on the back : stamens mona- 

 delphous below : plants nearly glabrous : stems erect or ascending : raceme terminal, 

 vanicled: stipules bristle-form, deciduous. 



1. D. Illldifldruiil, DC. Leaves all crowded at the summit of the sterile 

 stems ; leaflets broadly ovate, bluntish, whitish beneath ; raceme elongated, on a 

 prolonged ascending leafless stalk or scape from the root, 2 long. Dry woods ; 

 common. Aug. 



2. I>. acuminatum, DC. Leaves all crowded at the summit of the stem, 

 from which arises the elongated naked raceme or panicle; leaflets round-ovate, taper- 

 pointed, green both sides, the end one round (4' - 5' long). Eich woods. July. 



3. D. imur'illoruiii, DC. Leaves scattered along the low (8' -15' high) 

 ascending stems ; leaflets rhombic-ovate, bluntish, pale beneath ; raceme few- 

 Jlowered, terminal. Woods, W. New York and Penn. to Illinois and south- 

 westward. Aug. 



2. Pod short-stalked, of 3-5 joints : calyx-teeth longer than the tube : stipules 

 ovate, striate, pointed, persistent : stems prostrate : racemes axillary and terminal, 

 small, scarcely paraded. 



4. D. llll 111 if 11SUII1, Beck. Smoothish; leaflets ovate or oval; stipules 

 ovate-lanceolate; pods slightly sinuate along the upper margin, the joints obtusely 

 triangular. Woods, E. Massachusetts and Pennsylvania, rare. Aug. Re- 

 sembles the next. 



5. D. rotilildifolmm, DC. Hairy all over; leaflets orbicular, or the 

 odd one slightly rhomboid ; stipules large, broadly ovate ; pods almost equally 

 sinuate on both edges ; the joints rhomboid-oval. Dry rocky woods. Aug. 



T Pod kligh fly if at all stalked in the calijx ; the teeth of the latter loix/cr than t/ie 

 tul: : raci //.'<. s jxuticli d. 



