63 
rounder, with a fine but abundant pubescence, prominent dorsal ribs, and 
the numerous oil-tubes superficially distinct. In P. tomentosum not only 
the oil-tubes but the dorsal ribs are completely hidden by the tomentum. 
§ 3. Low and rather slender, from elongated comparatively slender 
roots: leaves rather small, more or less pinnately compound (the first 
division sometimes ternate), with short segments: fruit-wings narrow 
(never broader than body): oil-tubes 3 to 6 in the intervals (mostly solitary 
in P. nudicaule). 
* Floxvers white', fruit-wings more than half as xvide as 
» 
16. P. Nevadense Watson, Proc. Am. Acad. xi. 143. 
Glaucous, puberulent, shortly caulescent, peduncles 3 to 15 inches 
high: leaves pinnately decompound, with small segments: umhel 
unequally 5 to 10-rayed, with involucels of scarious-margined 
linear-lanceolate hractlets; rays often 1 to 2 inches long ; pedicels 
2 to 5 lines long: fruit rounded to ovate, somewhat pubescent 
(rarely glabrous), 3 to 5 lines long, 2 to 4 lines broad, with wings 
almost as broad as body, and evident dorsal and intermediate ribs: 
oil-tubes 3 or 4 in the intervals, 4 to 0 on the commissural side. — 
P. nudicaule of Watson, King’s Rep. v. 130, and others., not Nutt. 
East of the Sierra Nevada, from N. California and S. E. Oregon 
(UoiaeZO to Nevada and Utah. FI. ipril to June. 
17. P. nudicaule Nutt. Torr. & Gray, FI. i. 627. Acaules- 
cent or shortly caulescent, with peduncles 3 to 8 inches high, pubes- 
cent, from a thick elongated root (often swollen in places): leaves 
bipinnate, the small oblong segments entire or toothed: umbel un- 
equally 5 to 8-rayed, with involucels of scarious-margined (often 
purplish) lanceolate hractlets; rays to li/^ inches long; pedicels 
2^ to 3^ lines long; flowers white or pinkish: fruit almost round, 
emarginate at base, glabrous, lines long, 2 lines broad, with 
v/ings not as broad as body, and indistinct or obsolete dorsal and 
intermediate ribs: oil-tubes solitary in the intervals (rarely 2 in 
the lateral intervals), 4 on the commissural side: seed-face plane. 
(Fig. 51.) 
Arizona (Palmer 158 of 1876, 181 of 1877) and New Mexico northward to 
the boundary, and extending eastward to Minnesota, Iowa and Kansas, 
FI. March to May. 
This is one of our earliest bloomers and in this regard, in its own range, 
it represents the more eastern Erigenia. This is the Cymopterusi moniamis 
Porter & Coulter’s Flora Colorado, from plains near Denver. 
