LEGUMINOSH. (PEA FAMILY.) 43 
a half to two feet high; leaflets linear to narrowly lanceolate, sharply serrate; heads 
rather large, the flowers 6 to 8 lines long, purple, often tipped with white; valyx strongly 
nerved; the rigid teeth usually shorter than the tube, abruptly narrowed into the spinu- 
lose apex, often with a stout tooth on each side; ovules usually 2. 
Var. obtusiflorum, Wat. Stouter and often glandular-puberulent, with broader 
leaflets and larger flowers; calyx teeth entire. 
7. T. pauciflorum, Nutt. Smooth, very slender; stems ascending or decumbent; 
leaflets obovate to oblanceolate or sometimes linear, half an inch long or less, serrulate; 
heads few flowered; involucre small; flowers 3 or 4 lines long, not much exceeding the 
calyx; deep purple to light rose-colored; calyx teeth subulate, entire; pod 2-seeded. 
* * Involucre membr s, at least at the base, less deeply lobed; corolla not inflated. 
8. T. microcephalum, Pursh. Villous, with soft hairs, slender, erect or decum- 
bent; stems often a foot or two long; leaflets oblanceolate to obovate, usually retuse, 
serrviate; heads small, dense; involucre about 9-lobed, the lobes acuminate 3-nerved, 
entire; calyx hairy, nearly equaling the white or light rose-colored corolla; ovules 2; 
pod 1-seeded. 
9. T. microdon, Hook & Arn. Resembling the last; involucre broader, nearly 
inclosing the head; its lobes about 3-toothed; calyx smooth. 
*** Standard becoming conspicuously inflated and inclosing the rest of the flower; invo- 
lucre nearly obsolete in No. 12. 
10. T. barbigerum, Torr. Somewhat pubescent; stems rather stout, decumbent 
or ascending, a span high or less; stipules scarious; involucre as broad as the heads, 
shortly lobed; calyx-tube short, membranaceous; its teeth setaciously awned, plumose, 
the lower usually exceeding the purple corolla, sometimes 3-parted; pod 2-seeded. 
Var. Andrewsii, Gr. <A stout villous form, the heads sometimes an inch broad; 
calyx teeth very long. 
ll. T. fucatum, Lindl. Smooth; stems stout and succulent, a foot or two high; 
stipules large and scarious, usually very broad and entire; leaflets obovate, 4 to 14 inches 
long; heads large; involucre broad, deeply cleft; flowers often an inch long, pale rose- 
colored or purplish; 2-6-seeded. 
12, T. depauperatum, Desv. Smooth, low, slender; heads only 3-10-flowered; 
involucre scarcely more than a scarious ring. 
13. T. amplectans, Torr & Gr. Like the last; the involucre larger. Probably 
only a variety. 
5. MELILOTUS, Tourn. SweEet Clover. 
Flowers as in Trifolium, except that the petals are free from the stamens and decidu- 
ous. Pod 2-seeded. 
J. M. parviflora, Desf. Annual, smooth, erect, often 2 or 3 ft. high; leaflets 
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