56 
Systematic Synopsis. 
§ 1. Mostly low, from globose tubers (single or moniliforin): leaves 
small, more oi less dissected, with short segments (unless in P. ttnibiguum)'. 
fruit-wings narrow (not more than half as broad as body): oil-tubes mostly 
solitary in the intervals or with accessory ones in some species. 
* Always acaulescent and mostly glabrous: flowers white. 
1. P. Hendersoni C. & R. Bot. Gazette, xiii. 210. From a 
shallow constricted tuber 6 to 12 lines in diameter: leaves ternate 
then bipinnate, ultimate segments short and obtuse: umbel equally 
~ to 0-rayed, with involucels of linear acuminate scarious bractlets; 
rays about half inch long; pedicels 1^ to 2 lines long: fruit "ovate, 
glabious, 2 j 4 lines long, 2 lines broad, v/ith thickish narrow wings 
(not half as broad as body) more or less involute, filiform or nearly 
obsolete dorsal and intermediate nbs, and a rather prominent ridge 
on the commissural face: oil-tubes solitary in the intervals, 2 on the 
commissural side: seed-face plane. (Fig. 40.) 
On high hill-tops, Oregon, John Day Valley, May, 1882 {Howell B in 
part), and Lost Valley, June, 1882 (Howell 410). 
Dedicated to L. F. Henderson, one of our best Oregon collectors. The 
fruit of this species, in its thickish involute wings and rather prominent 
commissural ridge, very nearly approaches that ol Orogenia fusiformis 
Watson. 
2. P. Canbyi C. & R. Bot. Gazette, xiii. 78. Three to 
eight inches high, v/ith a short underground stem from a thick 
more or less elongated rootstock which ends in a globose tuber 6 
to 12 lines in diameter: leaves ternate-pinnatifid or bipinnate, 
ultimate segments small, with 3 to 5 linear-oblong lobes: umbel 
equally 5 to 10-rayed, with involucels of narrowl}^ linear scarious- 
margined bractlets; rays 1 to 2 inches long; pedicels 4 to 6 lines 
long: fruit oyate-oblong, glabrous, 4 lines long, 2^ lines broad, 
with wings about half as broad as body, and filiform dorsal and 
intermediate ribs: oil-tubes solitary in the intervals (lateral inter- 
vals often with 1 or 2 accessory but shorter ones), 2 or 4 on the 
commissural side. 
High ridges, E. Oregon {Howell, April, 1880, and May, 1882, no. 67; 
Cusick 1010, in 1882 and 1884) and Washington Territory, Klickitat county 
{Howell), and Spokane Eiver. 
This species ^as been referred to P. Nevadense, but always with a 
doubt. In Howell’s distribution it is labeled P. dasycarpum. It ha/ been 
collected too often in its early condition, before either fruit or leaves had 
matured, and in this state has been very puzzling. Mature fruit of Cusick’s 
