LEGUMINOSAE (PULSE FAMILY) 



519 



38. DESM6dIUM Desv. Tick Trefoil 



Calyx usually 2-lippecl. Standard obovate ; wings adherent to the straight 

 or straightish and usually truncate keel, by means of a little transverse append- 

 age on each side of the latter. Stamens diadelphous, U and 1, or monadelphous 

 below. Pod flat, deeply lobed on the lower margin, separating into flat reticu- 

 lated joints (mostly roughened with minute hooked hairs). — Perennial herbs, 

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

 lary or terminal racemes, often panicled, and 2 or 3 from each bract, purple or 

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

 striate. (Name from decr/xds, a bond or chain, from the connected joints of the 

 pods.) Meibomia Adans. 



K.B. — In this genus the figures of the loments are on a scale of 1|. 



§ 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-ohovate and concave on the back; sta- 

 mens monadelphous below; plants nearly 

 glabrous; stems erect or ascending ; raceme 

 terminal, panicled ; stipules bristle-form, 

 deciduous. 



nudiflorum. 



grandiflorum. 



1. D. nudiflorum (L.) DC. Leaves all crowded 

 at the summit of sterile stems; leaflets broadly 

 ovate, bluntish, whitish beneath ; raceme elon- 

 gated on an ascending mostly leafless stalk or scape 

 6-10 dm. high. {Meibomia Ktze.) — Dry woods, 

 s. Me. tow. Que., Out., Minn, and southw. Fig. 

 785. 



2. D. grandiflbrum (Walt.) 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 (1-1.8 dm. long). (D. acu- 

 minatum DC. ; Meibomia grandiflora Ktze.) 

 — Tiich woods, centr. Me. to Ont., S. Dak., 

 and southw. Fig. 786. 



3. D. pauciflbrum (Nutt.) DC. Leaves 

 scattered along the low (2-4 dm. high) 

 ascending stems ; leaflets rhombic-ovate, 

 bluntish, pale beneath ; raceme few-flowered, 

 terminal. {Meibomia Ktze.) — Woods, Ont. to Pa., Mich., Kan., and southw. 



§ 2. Pod raised on a stalk {stipe) little if at all surpassing the deeply cleft calyx ; 

 stems long and prostrate or decumbent ; racemes axillary and terminal. 



* Stiptdes conspicuous, ovate, attenuate, striate, persistent ; racemes mostly simple. 



4. D. rotundifolium (Michx.) DC. Soft-hairy all over, tvu\y T^ro&iYsXQ \ leaf- 

 lets orbicular, or the odd one slightly rhomboid ; flowers purple ; pods almost 



equally sinuate on both edges, .3-5-iointed ; 

 the joints rhomboid-oval. {Meibomia Mich- 

 auxii Vail.) — Dry woods, e. Mass. to Fla., 

 w. to Minn., Mo., and La. — A form with 

 ovate leaflets occur.s in Va. (Curtiss). 



5. D. ochroleucum M. A. Curtis. Stems 

 sparsely hairy, decumbent ; leaflets nearly 

 glabrous, ovate, acute or obtuse, transversely 

 reticulated beneath, the lateral ones smaller 

 or sometimes wanting ; racemes much elon- 

 gated ; corolla whitish; pods twisted, 2-4-jointed, the large rhomboid joints 

 smooth and reticulated but the margins downy. {Meibomia Ktze.) — Wood- 

 lands, N. J. and Del. to Ga. and Mo. Fig. 787. 



D. ochroleucum. 



