CROWFOOT FAMILY 297 



Leaves truncate or slightly cordate at the base, their primary lobes entire or merely 

 crenate; styles minute. 

 Floating water plants; at least some of the leaves cordate at the base. 



50. R. interlexlus. 

 Rooting mud plants; none of the leaves cordate at the base. 51. R. hyperboreus. 



XIV. MURICATI. 



One species. 52. R. arvensis. 



1. R. reptans L. Stem filiform, 1-3 dm. long; leaves 1-5 cm. long, linear- 

 filiform and glabrous to oblanceolate and strigose (var. slrigulosus Freyn); 

 peduncles 1-3 cm. long, filiform; petals obovate, 2-4 mm. long; head of fruit 

 spherical; achencs glabrous, with a minute beak. R. flammula reptans E. Meyer. 

 Shores: Lab.— N. J.— N.M.— Ore.— Alaska. Plain— Mont. My-S. 



2. R. unalaschensis Bess. Stem 3-6 dm. long, at first ascending, later 

 decumbent and rooting at the nodes; leaves 4-10 cm. long, petioled, sparingly 

 strigose or glabrous; blade lanceolate or oblanceolate, sometimes more than 1 

 cm. wide; petals obovate, 5-7 mm. long; head of fruit globose; achenes glabrous, 

 with a minute beak. R. Flammula intermedins Hook. Shores and wet pastures: 

 Alaska— Ida.— Calif.— Ont.—(? Newf.) Submont. My-Jl. 



3. R. microlonchus Greene. Stem 7-15 cm. high; basal leaves slender- 

 petioled; blades narrowly lanceolate, entire, 3-5 cm. long; cauUne leaves few, 

 relatively broader; flowers about S mm. broad; petals 5-8, obovate; achenes few 

 in a depressed globose head, obliquely obovoid, tipped with a stout style, gla- 

 brous. Wet places: n Ida. Au. 



4. R. alismaefolius Geyer. Stem glabrous or slightly hairy on the peduncles, 

 1-2 dm. (seldom 3 dm.) high, with rather spreading branches; basal leaves 1 dm. 

 or less long, glabrous, petioled, oval to lanceolate, entire or denticulate; cauline 

 leaves subsessile or short-petioled, lanceolate; petals obovate-oblong, 6-8 mm. 

 long; head of achenes depressed-globose; achenes glabrous; beak subulate, curved. 

 R. calthaefolius Greene. R. unguiculatus Greene, a form with somewhat clawed 

 petals. Wet cold soil, below the snow or in open woods: Wyo. — Colo. — Nev. — 

 Wash. Mont. — Subalp. Je-Au. 



5. R. Bolanderi Greene. Stem stout, 3-10 dm. high, glabrous, or the 

 peduncles strigose; basal leaves 1-2 dm. long, petioled, glabrous, lanceolate, 

 thick, callous-denticulate or entire; stem-leaves similar, subsessile; petals 5, 

 broadly obovate, 7-10 mm. long; achenes in a globose head, numerous, nearly 

 3 mm. long, with a subulate slightly curved beak. Wet places and shallow 

 water: B.C. — -Ida. — -Calif. Submont. Ap-Je. 



6. R. alismellus (A. Gray) Greene. Stem 1-2 dm. high, slender; basal 

 leaves 1 dm. long or less, glabrous, long-petioled, oval to eUiptic, acute at both 

 ends; stem-leaves similar; petals obovate, 5-6 mm. long; head of fruit globose, 

 4-5 mm. broad, glabrous, with a subulate beak. R. alismaefolius alismellus A. 

 Gray. Wet meadows and along streams: Wash.^Mont. — Wyo.— Calif. Sub- 

 mont. — Mont. Je-Au. 



7. R. Populago Greene. Stem 1.5-2 dm. high, glabrous, slender; basal 

 leaves long-petioled, glabrous; blades about 2 cm. wide, oval, to nearly round, 

 cordate or rounded at the base, 2-3 cm. long, subentire, thin; stem-leaves short- 

 petioled or subsessile, ovate, obtuse; petals 5-6, oblong-obovate; achenes gla- 

 brous, in a globose head. R. Cusickii M. E. Jones. Mountains: Ore. — Ida. — 

 Wash. Submoid. Jl-Au. 



8. R. Macauleyi A. Gray. Stem 1-1.5 dm. high, glabrous or sparingly 

 hairy above, the base surrounded by the remnants of old leaves; basal leaves 

 thick, 0.5-2 cm. wide, petioled, glabrous; blades oblong or elliptic or spatulate, 

 few-toothed at the apex; stem-leaves oblong-cuneate, sessile; petals broadly 

 obovate, deep yellow; heads of achenes ovoid, about 5 mm. broad; achenes 

 glabrous; beak 0.5 mm. long, subulate, nearly straight. Alpine peaks among 

 rocks: s Colo.^n N. M. Mont. — Subalp. Je-Jl. 



9. R. nivalis L. Stem more or less black-hairy, at least above; basal leaf- 

 blades 0.5-2 cm. wide, reniform or flabelliform, usually 3-cleft; middle lobe entire 

 or 3-toothed and the lateral ones 2-4-toothed; petals about 1 cm. long, broadly 



