pzucedanum. UMBELLIFER.E. 253 



high with a short subterranean stem from a deep-seated fusiform root : 

 leaves bipinnate, the ultimate divisions short and linear-oblong; umbel 

 unequally 1-5-rayed, with involucels of more or less united, often toothed 

 bractlets': fruit sessile or nearly so. ovate rough puberulent, 3 lines long, 

 with narrow wings, oil-tubes obscure, seed face plane. Simcoe Mountains, 

 Washington. 



P. Cons Watson 1. c. xxi, 453. Glabrous or slightly puberulent, with 

 roughish scapes 2-6 inches high from a nearly globose tuber 6-12 lines in 

 diameter: leaves pinnate: leaflets 3-7 parted or cleft or even entire; ulti- 

 mate divisions linear-oblong: umbel unequally 3-10-rayed, with involu- 

 cels of short oblong-ovate scarious-margined bractlets, rays from nearly 

 wanting to 2 inches long ; pedicels short : fruit oblong, more or less puber- 

 ulent, 2-4 lines long, 1-2 lines broad, with wings about half as broad as 

 the body, and prominent dorsal and intermediate ribs; oil-tubes large, 

 rilling the intervals : 4-6 on the commissure : seed-face plane with central 

 longitudinal ridge. On high gravelly ridges, John Day Valley* Oregon. 



P. ambiguum Nutt. T. &G.F1. i, 626. From low acaulescent to a 

 foot high and caulescent; glabrous : root tuberous, usually moniliform: pet- 

 ioles much dilated at base : leaves 1-2-pinnate with more or less elongated 

 linear leaflets, the upper often more dissecte l - : umbel unequally 8-1 8- rayed 

 with mostly no involucels : rays 1-4 inches long; pedicels 2-3 lines long : 

 fruit narrowly winged : oil-tubes 2 on the commissure. Oregon to Brit. 

 Columbia, Idaho and Montana. 



Tar. leptoearpum C. & R. Rev. Umb. 59. Fruit sessile or nearly so 

 making a close somewhat divaricate cluster : rays few and very unequal. 

 Oregon. 



P. circumdatum Watson 1. c. xxii. 478. Stem solitary from a deep- 

 seated constricted tuber, glabrous or puberulent a foot or less high: leaves 

 ternate-quinate. the ultimate divisions linear 1-4 lines long: umbel un- 

 equally 6-12-rayed, with involucels of conspicuous broadly oblanceolate 

 bractlets becoming scarious; rays %r^%. inches long; pedicels very short: 

 fruit oblong elliptical, glabrous, 3-4 lines long \ 1 . 2 lines broad, with nar- 

 row wings and very prominent dorsal and intermediate ribs : oil-tubes 4 

 on the commissure : seed-face concave with a prominent central ridge. 

 Oregon and Washington to Dakota. 



§ II. Stout, glabrous only in P. Grayi. from large roots : leaves 

 mostly large and very finely dissected, the ultimate segments filiform 

 or narrowly linear: fruit wings more than half as broad as the body : oil- 

 tubes 1-3 in the intervals, (solitary in P. Grayi and P. macrocarpum ) . 



* Flowers yellow : fruit glabrous : short caulescent. 



P. Grayi C. & R. Bot Gaz. xiii, 209. P. millefolium Watson. Gla- 

 brous, peduncles 2-20 inches long numerous from a thick perennial root : 

 leaves ternate-pinnately decompound, the ultimate segments linear, 

 elongated or short cuspidate, very numerous: umbel rather equally 6-16- 

 rayed, with involucels of distinct linear-subulate bractlets; rays 1-3* inches 

 long; pedicels 5-8 lines long: fruit oblong 4-8 lines long, 2-5 lines broad, 

 with filiform dorsal and intermediate ribs : oil-tubes usuallv solitary in 

 the intervals, 2-4 on the commissure. Common on dry rocky banks Ore- 

 gon and Washington to Utah. 



* * Flowers white. 



P. euryearpum C. & R. Rev. Umb. 61. Somewhat caulescent 6-12 

 inches high more or less pubescent from a long biennial caudex terminat- 

 ing below in a fusiform tuber: leaves bipinnate, segments pinnately in- 

 seised, ultimate divisions ovate or shortlv linear: umbel somewhat 



