4 PITTONIA. 
peduneles, moreover, in my plant are gradually thickened, 
and strongly so, under the fruit, so that possibly I am in- 
cluding two species under this name. 
SoME West AMERICAN SPECIES OF TRIFOLIUM. 
T. ottvaceum. Near T. Macro, 1-13 feet high, erect, with 
ascending branches, glabrous except a manifest appressed pu- 
bescence on the lower surface of the leaves: petioles an inch 
or two long, with lanceolate, acuminate, entire stipules: leaf- 
lets an inch long, euneate-oblong, obtuse, lightly serrulate or 
dentieulate : heads on elongated naked peduncles, hemis- 
pherical in flower, an inch broad and high: calyx-tube a line 
long, its slightly unequal linear-setaceous teeth 5—6 lines, 
densely plumose below, gradually less so above and nearly 
naked at the rather rigid tips: corolla deep violet-purple, 
only 2 lines long: legume. sessile, not exserted from the 
calyx-tube, striate-nerved, glabrous, 1-seeded. 
T. coLUMBINUM. Habit of the preceding but rather smaller, 
silky-pubescent throughout: leaflets with merely crenulate 
margins: flowering heads conical, more than an inch high 
and somewhat less than an inch broad at base: Galyx-tubé 
less than a line long, the filiform segments 5 lines, soft and 
densely silky-plumose throughout: corolla 14 lines long, vex- 
illum white, wings and keel deep purple: legume as in the 
last, but white-villous at apex. 
Both the above new clovers I found in May, 1886, growing 
quite plentifully, by waysides and along the borders of fields, 
near the village of Vacaville, hardly fifty miles north of San 
Francisco. But T. olivacewm had been brought by Mrs. Cur- 
ran, from the opposite side of the Sacramento valley near 
Penryn, two years before. They are annuals with a striking 
resemblance to T. arvense, completely hiding their small 
corollas within the mass of elongated, silky calyx-segments. 
The heads are of a rather bright olive green in the first 
