278 LEGUMINOSAE (PEA FAMILY) 



Introduced species grown for forage or pasture; widely naturalized. 



Stems creeping; flowers' white or pinkish 1. T. repens. 



Stems tufted, no creeping stems. 



Flowers sessile; heads sessile 2. T. pratense. 



Flowers pediceled; heads long-peduncled .... 3. T. hybridum. 



Indigenous species. 



Heads not involucrate. 



Stems slender, erect, 1-3 dm. nigh. 



Peduncles very short 4. T. latifolium. 



Peduncle much elongated 5. T. Rydbergii. 



Stemless or nearly so; often caespitose. 

 Leaves glabrous. 



Head of several flowers, pedunculate. 



Leaflets sharply denticulate 6. T. Haydenii. 



Leaflets entire 7. T. Brandegei. 



Flowers 1-3, on very short radical peduncles . . 8. T. nanum. 



Leaves pubescent, at least below . . . . . 9. T. gymnocarpon. 



Heads subtended by a many-cleft usually monophyllous involucre. 

 Low or dwarf perennials; acaulescent or nearly so. 



Glabrous, with large leaflets and long peduncles . . . 10. T. Parry i. 

 Pubescent. 



Distinctly pedunculate. 



Corolla bicolored, ochroleucous and purple . . . 11. T. dasyphyllum. 

 Corolla purple or red. 



Appressed silvery-pubescent; standard obtuse . . 12. T. anemophilum. 

 Sparsely hairy; standard attenuate . . . . 13. T. attenuatum. 

 Peduncle nearly wanting; the plants depressed-caespitose 14. T. andinum. 

 Slender, glabrous, and caulescent. 



Perennial, branching from the base ..... 15. T. Fendleri. 

 Annual, stems simple 16. T. Wormsjoldii. 



1. Trifolium repens L. Sp. PI. 767. 1753. Smooth perennial, the slender 

 stems creeping and spreading: leaflets inversely heart-shaped or merely 

 notched, obscurely toothed; stipules scale-like, narrow; petioles and especially 

 the peduncles very long: heads small and loose: calyx much shorter than the 

 white corolla: pods about 4-seeded. The common WHITE CLOVER. Widely 

 dispersed and now frequent in our range. 



2. Trifolium pratense L. 1. c. 768. Stems ascending, somewhat hairy: 

 leaflets oval or obovate, often notched at tip and with a pale spot above: 

 rose-purple flowers sessile in dense ovate heads; the corolla elongated-tubular. 

 The common RED CLOVER. In cultivation and escaped along roadsides and 

 ditch banks. 



3. Trifolium hybridum L. 1. c. 766. Perennial, erect or ascending, 3-6 dm. 

 high, nearly glabrous: leaves long-petioled ; the leaflets obovate, sharply 

 serrulate: heads globose, long-pedunculate; the flowers on slender pedicels. 

 ALSIKE CLOVER. -Sparingly naturalized. 



4. Trifolium latifolium (Hook.) Greene, Pitt. 3: 223. 1897. Stems erect, 

 scarcely tufted, few-leaved, 5-12 cm. high: leaflets oblong to oval, 7-15 mm. 

 long, glabrous as is also the stem and petioles: peduncles very short, pubescent: 

 heads spherical but soon loose; the flowers distinctly pediceled, reflexed in 

 age. T. longipes latifolium. (T. longipes Nutt. and T. Kingii Wats, are 

 probably wholly west of our range.) Occurs sparingly on our northwestern 

 border. 



5. Trifolium Rydbergii Greene, 1. c. 222. Nearly glabrous, the erect stems 

 1-4 dm. high, not tufted: leaflets of the lowest leaves short, oval; the others 

 oblong to linear-lanceolate, 2-4 cm. long: heads ovoid, about 2 cm. long: 

 r:ily\ :md peduncle somewhat pubescent or even slightly villous; the teeth of 

 the calyx much longer than the tube: corolla ochroleucous or nearly white, 

 sometimes purple-tinged. T. eriocephalum and T. longipes in part. Fre- 

 quent ; moist grassy valleys, in the open or among the undershrub ; through- 

 out our range. 



0. Trifolium Haydenii Porter, Hayden's Rep. 480. 1872. Glabrous and 

 eaespitoee. with branching caudex: leaflets obovate, obtuse or abruptly 

 pointfi, sharply denticulate, strongly veined: peduncle twice as long as the 

 tin- lower stipules obtuse, scarious; the upper acute: flowers purple, 

 large (lii i:> nun. long), in 2-3 verticils, reflexed in fruit: teeth of the calyx 

 Wtaoeous-aubulate, about as long as the tube: standard obtusely rounded or 

 emarginate. Northern Utah and adjacent Wyoming and Idaho. 



