STANDLEY FLORA OF, GLACIER PARK. 417 



Flowers lilue; loaves without spiny teeth, often lobed. 

 Achenes with a slender beak; leaves pale green; heads 1.5 to 2 cm. high. 



2. L. pulchella. 

 Achenes not l)eaked; leaves bright green on the upper surface; heads 1 cm. high. 



3. L. spicata. 



1. Lactuca virosa T>. Prickly lettuce. A few plants in dry soil at Belton. 

 Native of Eur.; introduced as a weed in N. Amer. — Biennial, 0.5 to 1.5 meters high, 

 hairy below; leaves oblong or obovate, 10 to 30 cm. long, clasping; heads 10 to 12 

 mm. high; flowers pale yellow. 



In many parts of the West this is a troublesome weed. 



2. Lactuca pulchella (Pursh) DC. Prairie lettuce. Rare on dry banks at east 

 entrance; perhaps introduced. B. C. to Calif., N. Mex., and Sask. — Glabrous 

 perennial, with rootstocks, 30 to 60 cm. high; leaves entire, toothed, or loljed; heads 

 in a narrow panicle. 



3. Lactuca spicata (Lam.) Hitchc. Tall lettuce. Frequent on the west slope 

 at low and middle altitudes, in thin woods or on open or brushy hillsides. Idaho to 

 Colo., N. C, and Newf. — Glabrous annual or biennial, 0.5 to 2 meters high, the 

 stem unbranched except at the top; leaves deeply lobed, the lobes usually toothed, 

 pale beneath; heads in a large panicle. 



4. SONCHUS L. 



1. Sonchus asper (L.) Hill. Sow thistle. Collected along railroad at Belton by 

 Umbach. Native of Eur.; naturalized as a weed in N. Amer. — Glabrous annual, 30 

 to 60 cm. high; leaves clasping, deeply lobed, with spinelike teeth; heads about 12 

 mm. high; flowers yellow; achenes flat, ribbed, the pappus of soft white bristles. 



5. PTILOCALAIS Greene. 



1. Ptilocalais nutans (Geyer) Greene. Collected on bluffs at east entrance by 



Umbach; also at Columbia Falls by Williams, and probably to be found at Belton. 



B. C. to Calif., Colo., and Mont. (Microseris nutans A. Gray.) — Perennial, 20 to 50 



cm. high, nearly glabrous; stems with few branches, sparsely leafy; leaves linear, 



entire, toothed, or with slender lobes; heads 10 to 15 mm. high, on long slender 



stalks; flowers yellow; pappus white, of hairy bristles, these dilated and scalelike 



at the base. 



6. CREPIS L. Hawksbeard. 



Low or tall perennials, usually with leafy stems; leaves entire, toothed, or lobed; 

 heads small or large, few or numerous; flowers yellow; achenes with short or no beak; 

 pappus of soft white bristles. 

 Leaves glabrous. 



Plants 10 to 20 cm. high; achenes with a conspicuous beak 1. C. elegans. 



Plants 3 to 8 cm. high, in small rounded tufts; achenes scarcely at all beaked. 



2. C. nana. 

 Leaves hairy. 



Bracts aliout 12, with gland-tipped hairs; leaves toothed or shallowly lobed. 



3. C. runcinata. 

 Bracts about 7, woolly, without gland-tipped hairs; leaves deeply lobed. 



4. C. intermedia. 

 1. Crepis elegans Hook. Occasional at low altitudes, on dry brushy slopes or dry 

 flats or along stream beds; abundant at St. Mary. Yukon to Wyo. ( Youngia 

 elegans Rydb.) — Plants much branched, forming rounded clumps; lowest leaves oval 

 to oblanceolate, 2 to 5 cm. long, entire, toothed, or lobed; heads about 8 mm. high; 

 bracts about 8. 



