26. Ranunculus flabcllaris Raf. Yellow water crowfoot. 



Glabrous or rarely hirsute perennial; roots filiform; stems floating or reclining, 

 rooting at the lower nodes. 3-7 dm. long, branching; petioles 3-8 mm. long, 

 composed wholly of the stipular leaf bases; leaves all cauline, alternate, the 

 blades finely triternately dissected, semicircular to reniform in outline, 1.5-10 

 cm. long, 2-12 cm. broad, the numerous divisions ribbonlike and 1-2 mm. broad, 

 not dissected in palustrine specimens in which the leaves are merely parted or 

 divided and with the divisions again lobed or parted; pedicels 1-5 cm. long in 

 flower, 2-6 cm. long in fruit, glabrous or hairy; sepals greenish-yellow, spread- 

 ing, ovate, 5-8 mm. long, 4-6 mm. broad, usually glabrous, early deciduous; 

 petals 5 to 8, yellow, obovate, 7-15 mm. long, 4-12 mm. broad; nectary scale 

 glabrous, free laterally, the gland in a pocket on the ventral surface of the scale; 

 stamens 50 to 80, the anthers 1-1.5 mm. long, oblong; achenes 50 to 75 in an 

 ovoid head 7-10 mm. long and 5-8 mm. in diameter, obovate, 2 mm. long, 

 smooth, glabrous, the margin conspicuously thickened into a corky keel, the 

 broad achene beak flat and 1.5 mm. long (straight); receptacle ovoid cylindroid, 

 2-3 mm. long in flower, 5-7 mm. long in fruit, hairy. 



In mud and water of shallow ponds, bayous and mud flats, in marshes and 

 swamps, Okla. {Waterfall), Apr.-Aug.; Me. to B.C., s. to N.C., La., Okla., Ut. 

 and Calif. 



27. Ranunculus Cymbalaria Pursh. Fig. 464. 



Glabrous or sparingly hirsute palustrine perennial; scapes erect, to 3 dm. high, 

 branched or unbranched, with filiform stolons several dm. long, not fistulous; 

 basal leaves with petioles 2-5 cm. long, simple, ovate or reniform to trapezoidal 

 or rectangular, to 35 mm. long and 2 cm. broad, crenate to dentate or sometimes 

 merely, 3-toothed or -lobed at the rounded to truncate apices, cordate to rounded 

 or truncate at base, the stipular leaf bases 2-9 mm. long; pedicels 1-3 cm. long 

 in flower and 2-6 cm. long in fruit, usually pubescent; sepals 5, greenish-yellow, 

 spreading, elliptic, 2-5 mm. long, 1.5-3 mm. broad, glabrous, thick, promptly 

 deciduous; petals 5 or up to 12, bright-yellow, narrowly obovate, 2-8 mm. long, 

 2-3 mm. broad; nectary scale over-arching the nectary, truncate, the margins 

 free from the blade of the petal; stamens 10 to 30; achenes as many as 300 

 (usually much fewer) in a cylindroid head 3-13 mm. long and 3-6 mm. in 

 diameter, cuneate-oblong, thin-walled, 1.5-2.3 mm. long, each face with about 

 4 longitudinal striations or branched nerves, glabrous, the margins noticeable, the 

 triangular beak about 0.3 mm. long and not curved; receptacle cylindroid, 2-3 

 mm. long in flower, 4-7 mm. long in fruit, hairy. 



In mud, especially of brackish streams and marshes, wet meadows, marshes, 

 and in shallow water about pools and along streams, in Okla. (Harper, Beaver, 

 Ellis, Texas and Cimarron cos.), N. M. (widespread), and Ariz. (Coconino, 

 Yavapai, Navajo, Apache, Mohave and Yuma cos.), May-Sept.; across Can. 

 to Alas, and Sib., s. to the Andes of S.A. 



The following two variants are found in our area. 



Var. Cymbalaria. Stems and petioles mostly 0.5 mm. thick; scapes 2.5-11 cm. 

 high, usually branched; basal leaves cordate to ovate or reniform, 5-22 mm. 

 long, 4-20 mm. broad, crenate or sometimes merely 3-lobed at the apices in 

 some of the leaves, thin; sepals and petals 3-5 mm. long; stamens usually 15 

 to 25; achenes 40 to 150 in a cylindroid head 3-8 or 13 mm. long and 3-4 or 

 6 mm. in diameter. 



Var. saximontanus Fern. Stems and petioles mostly 1 mm. thick; scapes 5-30 

 cm. high, usually branched; basal leaves cordate to ovate or rarely reniform, 

 12-40 mm. long, 10-33 mm. broad, mostly crenate, thick; sepals and petal 4-8 



953 



