Trifolium. LEGUMINOS^E. 217 



Sandy fields and roadgides, Massaclui'^ctts ! to Virginia ! Introdiirrd fnun 

 Euro|ii-. May-Sojjt. — (I) Flowers snialltT than in T. airrarium. — Tlii' tcr- 

 niinai leaflet is usually said to be jjttiululate, liut it is no more so than the 

 lateral ones : tlie common petiole is prolonged beyond the lateral leaflets; so 

 that the leaves are, in fact, pinnately triloliolale, as are several species of this 

 section. Seringe mentions a variety in which the leaves are sometimes pinnate. 



■ 20. 7\ nirrarinm {h'\nn.): stem ascendinfr or erect, minutely pubescent; 

 leaves on rather short ])etioles ; leaflets cunoate-oblonj^ or obovate-oblotic, of- 

 ten emar^jinate, denticulate, all subsessile ; stipules foliaceous, linear-lanceu- 

 late, coheiing with the petiole for more than half its length; heads of flowers 

 dense, on shortish peduncles terminating the branches, or sometimes axillary ; 

 teeth of the calvx unequil, the two upper ones shorter; vexillum striate 

 when old; leirume l-seedcd. — Piash, Ji. 2. p.AlS; DC. I. c. ; JJarlingl. 

 Ji. Cest. p. 408. 



Sandy fields and roadsides, Massachusetts ! to Pennsylvania ! Introdu- 

 ced from Europe. June-Aug. — (i) Stem 6-15 inches lonir, brandling. 

 Flowers, as in all the section, at length reflexed and imbricated downwards. 

 Leaves palmately trifoliolate. — Yello%p Clover. Jlop-Clovei-. 



§ 2. Heads of flowers subtended by a monophyUous (^usually many-cleft) 

 inrolucre. (Legume often dehiscent at the ventral suture: veins of the 

 leaves often reticulated.) — Involucrarium, Hook. 



A-21. T. microcephalum (Pursh) : pubescent or hairy, ascending or procum- 

 bent, branched; leaflets obcordate, or obovate-cuneiform and often emargin- 

 ate, denticulate; stipules ovate, acuminate, nearly entire ; heads subglobose 

 (small), on long axillary peduncles ; involucre many-clefi, the segments 

 equal, entire ; calyx hairy ; the teeth equal, straight, subulate, broad at the 

 base, as long as the tube, about the length of the corolla; legvmie indehiscent, 

 1-seeded.— /■'urs/i, fl. 2. p. 478 ; DC. prodr. 2. p. 207 ; nou/c. ! fl. Bor.-Am. 

 1. p. 132. (excl. /?.?) 



Oregon, from the mountains to near the sea, Lewis, Dr. Scouler ! Nut- 

 tall ! California, Menzies. — Stem 6-12 inches or more long, slender. 

 Heads about one-fourth of an inch in length. Segments of the involucre about 

 9. Legume turgid. 



22. T. variegatum. (Nutt. ! mss.) : "glabrous, decumbent, branching ; leaf- 

 lets obovate-oblong or somewhat obcordate, minutt ly spinulose-serrate ; up- 

 per stipules roundish, laciniately dentate with subulate-setaceous teeth ; pe- 

 duncles axillary, longer than the leaves ; involucre laciniately many-cleft, 

 shorter than the subglobose head ; teeth of the glabrous calvx equal, lanceolate- 

 subulate, w ith setaceous points, much longer than the tube, shorter than the 

 corolla; legume dehiscent, 1-2-seeded."— T. microcephalum fi. glabrum, 

 Hook. I. c. ? 



fi. heads larger; peduncles twice the length of the leaves. 



Springy places near the mouth of the Wahlamet, Nuttall ! 0. California, 

 Douglas ! — (y) Stem S-12 inches long. Lower leaflets with a lunulata 

 spot. Heads about hall an inch in diameter. Corolla dull purple, whitish 

 at the tip. 

 -^ 23. T. fimbriatum (Lindl.) : prostrate, glabrous ; leaflets oblons: or slightly 

 cuneate, spinulose-denticulate ; stipules ovate, acuminate, laciniate-spinulose; 

 involucre laciniately many-cleft, shorter than the subglobose heads; teeth of 

 the calyx broadly subulate, straight, half the length of the corolla [legumes 

 2-seeded]. //oo/i.— /v?«d/. bot. reg.t. 1070; Hook.fi. Bor.-Am. I. p. 133; 

 Hook. <!^ Am. bot. Beechey, p. 137. ♦ 



Common in salt marshes of the N. W. Coast from Cape Orford to Califor- 

 nia. Menzies, Douglas, Dr. Scouler. (v.s. in hort.) — Stems long and thick. 



