=Tick Trefoil, Desmodium rotundifolium.=

47b. Plants decumbent or ascending; racemes short, simple, few-flowered;
stipules ovate (stems 4-8 dm. long)
=Tick Trefoil, Desmodium pauciflorum.=

47c. Plants erect or ascending; racemes panicled --48.

48a. Leaflets of an oblong type, broadest at or near the middle,
and about 4 times as long as broad (5-10 dm. tall) --49.

48b. Leaflets of an ovate or lanceolate type, broadest below the
middle, and not more than 3 times as long as wide --50.

49a. Stem pubescent; leaves sessile or nearly so
=Tick Trefoil, Desmodium sessilifolium.=

49b. Stem glabrous or nearly so; leaves obviously petioled
=Tick Trefoil, Desmodium paniculatum.=

50a. Stipules lanceolate to ovate, 1 cm. long or more (6-15 dm.
high) --51.

50b. Stipules narrowly lanceolate or subulate, less than 1 cm. long
--54.

51a. Stems glabrous or minutely pubescent; leaves acuminate --52.

51b. Stems hispid or densely pubescent; leaves ovate or
ovate-lanceolate, obtuse or barely acute --53.

52a. Leaves glabrous on both sides
=Tick Trefoil, Desmodium bracteosum.=

52b. Leaves rough above, hairy beneath
=Tick Trefoil, Desmodium bracteosum var. longifolium.=

53a. Leaflets broadly ovate =Tick Trefoil, Desmodium canescens.=

53b. Leaflets ovate-lanceolate =Tick Trefoil, Desmodium illinoense.=

54a. Flowers 10-12 mm. long (1-2 m. high)
=Tick Trefoil, Desmodium canadense.=

54b. Flowers 5-8 mm. long (5-8 dm. tall) --55.

54c. Flowers 3-4 mm. long (4-8 dm. tall) --56.

55a. Leaflets broadly ovate =Tick Trefoil, Desmodium viridiflorum.=

55b. Leaflets oblong-ovate =Tick Trefoil, Desmodium dillenii.=

56a. Leaflets 3-5 cm. long, oblong-ovate, scabrous above
=Tick Trefoil, Desmodium rigidum.=

56b. Leaflets 1-2.5 cm. long, broadly ovate or oval, not scabrous
above --57.

57a. Stem and leaves glabrous or very nearly so
=Tick Trefoil, Desmodium marilandicum.=

57b. Stem and leaves conspicuously pubescent
=Tick Trefoil, Desmodium obtusum.=

58a.