540 FLORA. 



the base, rounded, truncate or emarginateat the apex, 12-18 mm. long; peduncles 

 1-5 cm. lung, "head oblong, or oval, densely many-flowered; flowers 4-6 mm. long, 

 at length reflexed; pedicels shorter than the calyx; standard slightly emarginate,' 

 exceeding the pod, conspicuously striate, and brown, especially when dry. Along 

 roadsides and in waste places, N. S. to Va., Ont. and Iowa. Nat. from Europe. 

 May-Sept. [T. agrarium L., in part.] This species and the two following are 

 sometimes referred to the genus Chrysaspis Desv. 



2. Trifolium procumbens L. Low, or Smaller Hop-clover or Hop- 

 trefoil. (I- F. f. 2071.) Similar to the preceding, but lower, more spreading 

 and more pubescent. Leaflets obovate, cuneate at the base, rounded, truncate or 

 emarginate at the apex, finely denticulate, 7-15 mm. long, the lateral ones nearly 

 sessile, the terminal stalked ; stipules ovate, adnate to the lower part of the 

 petiole, about 4 mm. long; peduncles 5-25 mm. long; heads 20-40-flowered; flowers 

 at length reflexed, about 4 mm. long; standard dilated, not folded, exceeding the 

 pod, brown when dry. In fields and along roadsides, frequent or occasional 

 throughout our area and in the Southern States. Nat. from Europe. May- Sept. 



3. Trifolium dubium Sibth. Least Hop-clover or Hop-trefoil. (I. F. 

 f. 2072.) Straggling or ascending, nearly glabrous; stems 5 cm. -5 dm. long, branch- 

 ing. Leaflets obovate, truncate or emarginate at the apex, or even obcordate, denticu- 

 late, cuneate at the base, the lateral ones nearly sessile, the terminal stalked ; stip- 

 ules ovate or lanceolate, adnate to the lower part of the petiole ; peduncles 5-25 

 mm. long; heads nearly globose, 4-6 mm. in diameter; flowers about 3 mm. long, 

 turning brown, at length reflexed; standard exceeding and folded over the pod. In 

 fields and waste places, N. Eng., N. J. and in the Southern States. Also in Br. 

 Col. Nat. from Europe. Summer. Said to be the true Shamrock. 



4. Trifolium incarnatum L. Crimson, or Italian Clover. (I. F. f. 

 2073.) Annual, softly pubescent, little branched, 2-9 dm. high. Leaves long- 

 petioled; stipules broad, membranous, dentate, 7-25 mm. wide; leaflets nearly ses- 

 sile, obovate or obcordate, narrowed or cuneate at the base, denticulate, 12-25 mm - 

 long; 'heads terminal, oblong or ovoid, 2.5-6 cm. long; flowers sessile, 7-12 mm. 

 long; calyx hairy, calyx-lobes plumose. In fields, waste places and ballast, Me. 

 to N. Y., N. J. and Penn. Introduced from Europe. Summer. 



5. Trifolium arvense L. Rabbit-foot, Old-field or Stone Clover. 

 (I. F. f. 2074.) Annual, erect, silky-pubescent, 1.5-5 dm. high. Leaves short- 

 petioled; stipules narrow, 5-10 mm. long, subulate-tipped, entire or nearly so ; 

 leaflets linear or oblanceolate, denticulate above, obtuse and often emarginate, nar- 

 rowed or cuneate at the base, 12-25 mm. long; heads terminal, peduncled, oblong 

 or cylindric, 12-25 mm. long, very dense; calyx very silky. In fields and waste 

 places, common in most sections throughout our area and in the Southern States. 

 Nat. from Europe. May-Sept. 



6. Trifolium pratense L. Red, Purple or Meadow Clover. (I. F. f. 

 2075.) Perennial, pubescent, 1.5-6 dm. high. Leaves long-petioled ; stipules 

 ovate, strongly veined, subulate-tipped, 12-20 mm. long; leaflets short- stalked, 

 oval, oblong or obovate, narrowed at base, hardly cuneate, obtuse and sometimes 

 emarginate at the apex, often dark-spotted near the middle, finely denticulate, 1- 

 3.5 cm. long; heads globose or ovoid, rarely slightly peduncled, about 2.5 cm. 

 long; flowers red (rarely white), about 12 mm. long, remaining erect >n fruit; calyx 

 sparingly hairy, its subulate teeth shorter than the corolla. In fields and meadows, 

 throughout our area and in the Southern States. Nat. from Europe. April-Nov. 



7. Trifolium medium L. Zig-zag Clover. Cow- or Marl-grass. (I. F. 

 f. 2076.) Resembling the preceding. Stem sometimes conspicuously zigzag. Stip- 

 ules lanceolate; leaflets lanceolate or oblong, not spotted, frequently entire except 

 for the projecting tips of the veins; corolla 12-14 mm. long, bright purple; calyx- 

 tube nearly glabrous, the teeth slightly pubescent. In fields and waste places, 

 Salem, Mass. Reported from N. S. and Quebec to N. Y. Adventive or nat. from 

 Europe. Summer. 



8. Trifolium Beckwithii Brewer. Beckwith's Clover. (I. F. f. 2077.) 

 Perennial; stems rather stout, straight, 1.5-5 dm. high. Basal leaves long-petioled; 

 stipules narrow, acute, 2.5 cm. long or less ; leaflets oblong, or somewhat oblan- 

 ceolate. obtuse, denticulate. 25 cm. long; heads long-peduncled, glolx)se; flowers 

 purple or purplish, 12-16 mm. long, very short-pedicelled, the lower at length re- 



