256 
AMMIACEAE. 
24. LOMATIUM C. & R. 
Plants slender with thick rounded corms; corolla yellow. 1. L. leptocarpum. 
Plant generally stouter from a thickened root or rootstock, rarely corm-like. 
Bractlets lanceolate, oblong or linear; corolla white. 
Bractlets scarious-margined, as well as the whole plant puberulent or rarely 
glabrate. 2. L. orientale. 
Bractlets not scarious-margined, villous. 3. L. macrocarpum. 
Bractlets of the involucels none or very few, linear or subulate; corolla yellow. 
Leaves finely dissected with numerous small divisions. 4. L. Grayi. 
Leaves once to thrice ternate with comparatively large divisions. 
5. L. platycarpum. 
1. Lomatium leptocarpum (Nutt.) C. & R. ( Peucedanum leptocarpum 
Nutt.) On plains and hillsides from Ida. and Ore. to Colo, and Calif.— 
Steamboat Springs. 
2. Lomatium orientale C. & R. ( Peucedanum nudicaule Nutt., mainly) On 
dry plains from S. D., Mont, and Ida. to Kans., N. M. and Ariz.—Alt. 4000- 
8000 ft.—Plains near Denver; foot-hills west of Ft. Collins; mountains, 
Larimer Co.; Calhan; vicinity of Horsetooth; Horsetooth Gulch; Dixon 
Canon; Empire. 
3. Lomatium macrocarpum (Nutt.) C. & R. ( Peucedanum macrocarpum 
Nutt.) Dry hills and plains from Sask. and B. C. to Colo, and Calif.— 
Egeria Park, Routt County. 
4. Lomatium Grayi C. & R. On dry plains and hills from Wyo. and 
Wash, to Colo, and Ore.—Alt. up to 7000 ft.—Mancos; Durango; Los Pinos; 
Glenwood Springs. 
5. Lomatium platycarpum (Torr.) C. & R. ( Peucedanum simplex Nutt.) 
On hillsides from Alb. and Wash, to Colo, and Ore.—Alt. 6000-8000 ft.— 
Above Mancos; Mancos; Cerro Summit; Glenwood Springs; Fort Lewis. 
25. PSEUDOCYMOPTERUS C. & R. 
Plant more or less caulescent; leaves thin. 
Petals yellow. 
Ultimate divisions or teeth of the leaves short, ovate to lanceolate; leaves 
ovate in outline. 1. P. montanus. 
Ultimate divisions of the leaves linear, elongated. 
Leaves ovate in outline, at least the basal ones. 2. P. sylvaticus. 
Leaves, at least the basal ones, broadly rhombic in outline. 
Plant slender; leaves mostly twice compound with very long and few 
divisions. 3. P. tenuifolius. 
Plant low; leaves thrice pinnate with shorter, crowded numerous 
divisions. 4. P. multiddus. 
Petals purple. 5. P. purpureus. 
Plants acaulescent with thick or firm leaves. 
Primary divisions of the leaves once or twice dissected with narrowly linear 
divisions. 6. P. anisatus. 
Primary divisions broad, cuneate-flabellate, cleft and toothed with short ovate 
or lanceolate teeth. 7. P. aletifolius. 
1. Pseudocymopterus montanus (A. Gray) C. & R. ( Ligusticum mon- 
tanum B. & H.) In mountain woods from Wyo. to N. M. and Ariz.—Alt. 
8000-12,500 ft.—Headwaters of Clear Creek; Clear Creek Canon; Cumbres; 
Cumberland Basin, La Plata Mountains; Los Pinos; hills above Mancos; 
West Indian Creek; Sangre de Cristo Canon; Cameron Pass; Alpine Tunnel; 
