CROWFOOT FAMILY 287 



styles 4-6 mm. long; leaves 3^ times temate: segments narrowly linear. 



6. A. Drummondii. 

 Styles subulate, persistent: heads of fruit from rounded oblong to cylindric; 

 involucral leaves long-petioled. 

 Heads elongate, cylindric; styles about 1 mm. long; flowers usually subumbel- 



late. 7. A. cylindrica. 



Heads of fruit rounded-oblong ; styles about 2 mm. long ; flowers truly cymose. 

 Petals greenish white, 1 cm. long or less; styles in fruit divergent. 



8. A. virginiana. 

 Petals white, 1.5 cm. long; styles suberect. 9. A. riparia. 



Achenes not villous. 



Achenes wing-margined: plant stout. 



Sepals yellow; styles very long, reflexed. 10. A. Richardsoni. 



Sepals white or pink; styles not refle.xed. 



Flowers cymose: achenes sparsely hirsute when young, sessile: styles long, 



straight. 11. A. canadensis. 



Flowers subumbellate: achenes glabrous, stipitate: styles short, curved. 



12. A. zephyra. 

 Achenes not wing-margined, pilose; style minute; plant slender; flowers solitary. 



13. A. Piperi. 



1. A. tuberosa Rydb. Stem 1-3 dm. high; basal leaves twice temate; 

 divisions rhombic-cuneate in outline, ternately cleft and toothed; involucral 

 leaves similar, but short-petioled ; peduncle sohtary or a second one with a smaller 

 involucre; sepals white or purplish, oblong-linear, 1-2 cm. long; head of fruit 

 eUipsoid; achenes densely woolly; style filiform, about 1.5 mm. long. A. spheno- 

 phylla Britton, not Poepp. Dry plains and hills: N.M. — -Utah — Calif. L. 

 Son. F-Ap. 



2. A. parviflora Michx. Stem 5-20 cm. high; leaves ternate, thick, and 

 firm, glabrous above, silky-strigose beneath; divisions cuneate, 1-2 cm. long; 

 sepals white or tinged with bluish or rose, oval, 8-18 mm. long; head of fruit 

 spherical. In arctic-alpine situations: Lab. — Ont. — JMont. — Colo. — Alaska; Asia. 

 Mont. — Suhalp. My-Au. 



3. A. tetonensis Porter. Stem silky, 1-3 dm. high, 1-3-flowered, the 

 secondary peduncles with smaller involucres; leaf-blades twice ternate, 2-5 cm. 

 broad; involucral leaves similar, but sessile; sepals oval, 6-10 mm. long, often 

 dark purple, more rarely white, and tinged with blue on the outside; head of 

 fruit hemispherical, 10-15 mm. in diameter. A. stylosa A. Xels. Mountains: 

 Alta. — Wyo. — -Utah — Wash. — B.C. Submont. — Subalp. Jl-Au. 



4. A. lithophila Rydb. Stem 1-2 dm. high, sparingly pubescent with long 

 silky hairs; basal leaves thickish, shining, somewhat glaucous; divisions 

 about 3 cm. long, deeply 3-cleft, again cleft and toothed; sepals silky, ochroleu- 

 cous, tinged with blue, 12-15 mm. long, broadly obovate or oval; head of fruit 

 globose. Rocky mountain tops : Mont. — Wyo. — Utah. Submojit.— Subalp. Jl- 

 Au. 



5. A. globosa Nutt. Stem 2-5 dm. high, silky- villous, 1-3-flowered; leaf- 

 blades 5-12 cm. broad, thrice cleft; sepals oval, 6-12 mm. long, pink or purplish 

 or ochroleucous, tinged with bluish on the outside; heads of fruit globose or ovoid, 

 10-12 mm. in diameter. A. multifida Hook., in part, not Poir. Meadows and 

 hillsides: Alaska— Calif.— Colo.— S.D.—Sask.— Mack. Plain—Suhalp. My-S. 



6. A. Drummondii S. Wats. Stem 1-2 dm. high, usually 1-fiowered, silky- 

 hirsute; leaf -blades 2-6 cm. broad, silky-hirsute; sepals oval, 8-10 mm. long, 

 tinged with blue; heads of fruit spherical, about 1 cm. thick; achenes densely 

 woolly. High mountains: B.C. — -Alta. — -Ida. — Calif. Mont. — -Subalp. Jl-Au. 



7. A. cylindrica A. Gray. Stem 3-6 dm. high, 1-10-flowered; leaf-blades 

 strigose-pubescent, 3-8 cm. wide, ternate or quinnate; divisions rhombic-ctmeate, 

 3-cleft and again cleft or toothed, with ovate or lanceolate teeth or lobes; invo- 

 lucral ones similar, clustered together with those of the secondary peduncles, 

 the lowest node of which usually is xery short or obsolete, the inflorescence there- 

 fore becoming umbelliform; sepals greenish white, oblong, 8-10 mm. long; heads 

 in fruit 2—4 cm. long, about 1 cm. thick. Meadows, hillsides, and river banks: 

 N.B. — ^X.J. — Ariz. — -B.C. Plain — Submont. Je-Au. 



8. A. virginiana L. Stem 6-10 dm. high, hirsute, 1-7-flowered; leaf-blades 

 10-15 cm. broad, ternate or quinate, more or less silky-hirsute; divisions rhom- 



