Vor. II.] PEA FAMILY. 275 
1. Trifolium agrarium I. Yellow or Hop-clover. (Fig. 2070.) 
Trifolium agrarium J,. Sp. Pl. 772. 1753. 
ules linear-lanceolate, acuminate, 4’/-7’’ long, ad- 
nate to the petiole for about one-half its length; 
leaflets all from the same point, sessile, obovate or 
oblong, finely denticulate, narrowed at the base, 
rounded, truncate or emarginate at the apex, 6’’-9/” 
long; peduncles axillary, }2’-2’ long; head oblong, 
or oval, 6-9’ long, densely many-flowered; flowers 
yellow, 2/’-3’’ 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, Nova Scotia to 
Virginia, west to Ontario, western New York and Iowa. 
Naturalized from Europe. May-Sept. 
2. Trifolium procumbens I, Low, or Smaller 
Hop-clover or Hop-trefoil. (Fig. 2071.) 
Trifolium procumbens I. Sp. Pl. 772. 1753. 
Similar to the preceding species, but lower, more spread- 
ing and more pubescent. Leaflets obovate, cuneate at the 
base, rounded, truncate or emarginate at the apex, finely 
denticulate, 4/’-7’’ long, the lateral ones nearly sessile, the 
terminal distinctly stalked; stipules ovate, adnate to the 
lower part of the petiole, about 2’’ long; peduncles 3//— 
12’’ long; heads 20-40-flowered, globose or short-oval, 
4/’-6/ in greatest diameter; flowers yellow, at length 
reflexed, about 2/’ long; standard dilated, not folded, 
exceeding the pod, striate and brown when dry. 
In fields and along roadsides, frequent or occasional 
throughout our area and in the southern States. Naturalized 
from Europe. May-—Sept. 
3. Trifolium dubium Sibth. Least Hop- “9\ Ne 9 
clover or Hop-trefoil. (Fig. 2072.) yy ay a 
WIA H . 
Trifolium dubium Sibth. Fl. Oxon. 231. 1794. “& LAG, WD 
Trifolium minus Smith, Engl. Bot. f/. 1256. 1799. NS PSS / 
Trifolium procumbens var. minus Koch, Fl. Germ. & Q\ as ed 
Helv. Ed. 2, 195. 1843. S yy fe 
Straggling or ascending, nearly glabrous, stems 2/— I 
20’ long, branching. Leaflets obovate, truncate or JQ ee. K 
emarginate at the apex, or even obcordate, denticu- & i) 
late, cuneate at the base, the lateral ones nearly ses- 
sile, the terminal stalked; stipules ovate or lanceo- 
late, adnate to the lower part of the petiole; peduncles 
3//-12” long; heads nearly globose, 2’/-3/’ in diam- 
eter, 3-20-flowered; flowers about 114/’’ long, turn- 
ing brown, at length reflexed; standard exceeding 
and folded over the pod, scarcely striate. 
In fields and waste places, New England, New Jersey 
and in the southern States. Also in British Columbia. 
Naturalized from Europe. Summer. Said to be the true 
Shamrock. Called also Yellow Suckling, Wild Trefoil. 
