70 



oblong to nearly c)i!)iciilar, soniclinics cmaiginatc at each end, '4 to 

 6 lines long, 2 to 5 lines broad, with wings broader than bod)- 

 (also extending below body ), and prominent dorsal and intermed- 

 iate ribs: oil-tubes large and solitary in the intervals, 2 on the com- 

 missural side: seed-face slightly concave. (Fig. 64.) — P. tritcriia- 

 ttim^ var. •platycarpum Torr, Stansb. Rep. 389. 



From Arizona and California (J/. K. Cnrran) to Washington Tcnitory. 

 Idaho, and Montana. 



In determining this species it is important to remember that wings 

 develope lasit, and hence very mature truit must be obtained to show wings 

 of full width. 



84. P. triternatum Nutt. Torr. & Gray, P^l. i. 026. Cau- 

 lescent or acquiescent, puberulent, 1 to 2}4 i^^^ high: leaves biter- 

 nate to triternate; leaflets from narrowly linear to linear-lanceolate, 

 2 to 4 inches long: umbel unequally T) to 18-rayed, with invol- 

 ucels of lanceolate or setaceous bractlets; rays % to 2% inches 

 long; pedicels a line or more long: fruit narrowly oblong, 

 glabrous (rarely pubescent), 8 to 6 lines long, 1 J^ to 2 lines 

 broad, with narrow v/ings, and somewhat prominent dorsal and 

 intermediate ribs: oil-tubes very large and broad, solitary in the 

 intervals, 2 on the commissural side: seed-face very slightly con- 

 cave. (Fig. 65.) — Incl. P. triternattim^ var. hptocarpuni Nutt. 



From California to Washington Territory, Idaho, and British Columbia 

 (Mac.oun). Fl. April to June. 



One of the most abundant and variable of our species. It shades off 

 towards P. Himplex sometimes in a most perplexing way. The following 

 are extreme forms: 



Var. macrocarpum. A more robust form, with broader 

 leaflets, longer rays, and larger fruit (6 to 8 lines long). 



Oregon (8M/.-.sr/o*-/r)02). Dalles [Kel'ofio, in 1869), Hood River (Hcmhr- 

 mn 390). 



Var. brevifolium. vStouter and more rough puberulent, with 

 more compact leaves, having stout inflated petioles, and shorter 

 and broader often toothed leaflets. 



Oregon, Klickitat county (Hovrll 379. in 18S1), and rocky hillsides near 

 the Dalles (HnkHdorf). 



Var. alatum. Leaves with very narrowly linear and elon- 

 gated segments; fruit T) to lines long, with broader wings (some- 

 times as broad as body or even broader), but the elongated form is 

 that of P. trUernahtin and not /'. siniflcs. 



