PEUCEDAXUM. 



TJMBELLIFERjE. 255 



rough pubescent petioles wholly inflated, with a very conspicuous white 

 scarious margin ; leaves ternately or pinnately dissected, the ultimate seg- 

 ments very short, linear : umbel very unequally 6-15-rayed, with involu- 

 cels of distinct linear-lanceolate bractlets ; rays 1-4 inches long; pedicels a 

 line or two long ; flowers bright yellow : fruit ovate puberulent 2-2J4 lines 

 long with very narrow wings, and filiform dorsal and intermediate ribs 

 oil-tubes 4-5 in the intervals 6 on the commissure : seed-face plane. Bare 

 mountain tops, Northern Idaho and Montana to Brit. Columbia. 



P. microcarpum Howell P. C. PI. Coll. 1887. Caulescent, branching 

 from the base 6-16 inches high, glabrous: leaves pinnately-decompound 

 the ultimate segments oblong- to linear-lanceolate : minutely cuspidate : 

 umbel somewhat equally lu-18-rayed with involucels of several linear- 

 lanceolate bractlets 1-3 lines long: pedicels 2 lines long, flowers dark 

 yellow : fruit oblong 3 lines long 2 lines broad with narrow wings : oil-tubes 

 4 on the commissure. On dry cliffs, Umpqua Valley. 



§ IV. Shortly caulescent, slender from elongated comparatively 

 slender roots ; glabrous ; leaves small, lanceolate or oblong in outline, 

 pinnate or bipinnate with ovate toothed segments. 



* Fruit wings half as broad as the body. 



P. Hallii Watson Proc. Am. Acad, xi, 141. Peduncles elongated 6-15 

 inches high: leaves pinnate oblong in outline, the ovate segments ^-inch 

 long, deeply toothed or pinnatifid : umbel equally 3-6-rayed, with small 

 involucels; rays about an inch long; pedicels 3-1 lines long: flowers yel- 

 low : fruit broadly elliptical 3 lines long, 2 lines broad with filiform dorsal 

 and intermediate' ribs, oil-tubes 3 in the intervals 4-6 on the commissure. 

 Northern Oregon and Washington. 



* * Fruit wings much broader than the body. 



P. Martindalei C. & R. Bot. Gaz. xiii, 1-42. Caulescent and branching, 

 with elongated peduncles 4-12 inches high : leaves pinnate, or bipinnate 

 with toothed or pinnatifid segment: fruit 4-7 lines long, 3-4 lines broad, 

 with wings as broad or broader than the body, and prominent dorsal and 

 intermediate ribs; oil-tubes solitary in the intervals, 2 on the commissure, 

 seed-face somewhat concave with central longitudinal ridge. On bluffs of 

 the Columbia river, near the Cascades. 



Var. augustatum C. & R. 1. c. 143. Usually more caulescent and 

 sometimes taller with more dissected leaves, and wings of the fruit but 

 half a line wide making a fruit 2 lines wide. On high mountains, Brit. 

 Columbia to California. 



§ V. Caulescent ; from elongated comparatively slender roots: leaves 

 decompound with narrow linear more or less elongated segments and 

 usually wholly dilated petioles: bractlets of the involucels scarious - 

 margined more or les3 conspicuous. 



* Wings of the fruit nearly as broad as the body, thin : oil-tubes 

 large _ and solitary in the intervals : dorsal and intermediate ribs 

 prominent. 



P. utriculatum Nutt. T. & G. Fl. i, 628. Caulescent to nearly acaul- 

 escent, 4-12 inches high from a more or less tuberous root, puberulent or 

 glabrous : petioles very broadly dilated ; leaves ternately or pinnately de- 

 compound, with ultimate segments narrowly linear, 6 lines long or'less : 

 umbel unequally 5-20-rayed with involucels Vjf much dilated mostly obo- 

 vate often toothed petiolulate bractlets; rays about 2 inches long, pedicels 

 2-5 lines long ; flowers yellow; fruit broadly elliptical, glabrous, 2-5 lines 

 long, 1-3 lines broad: oil-tubes 4-6 on the commissure : seed-face some- 



