or 7 linear divisions some of which are again lobed, the blade proximally cordate, 

 the lobes distally acute or obtuse, thinly pilose to glabrous; cauline leaves alter- 

 nate, the bracts divided into 3 to 7 linear lobes, sessile; flowers 1 to 5 or some- 

 times 8; pedicels 1.5-7 cm. long in flower, 5-14 cm. long in fruit, pilose; 

 sepals greenish-yellow but ashy with dense pubescence, spreading, obovate, 

 deeply concave, the tips abruptly becoming petaloid, 4—6 mm. long, 3-5 mm. 

 wide, densely pilose dorsally, tardily deciduous after anthesis; petals 5 or rarely 

 none, yellow, broadly cuneate-obovate, 8-10 mm. long, 5-7 mm. wide; nectary 

 scale glabrous, forming a pocket 0.4-1.5 mm. long and 0.4 mm. wide, sometimes 

 deeply parted, truncate; stamens 25 to 60; achenes 25 or usually 40 to 70 in a 

 cylindroid head 8-10 mm. long and 5-6 mm. in diameter, flattened-obovoid, 

 about 2 mm. long, smooth, very finely canescent or glabrate, the slender beak 

 0.6-1 mm. long and recurved; receptacle ovoid to obovoid or cylindroid, 2-3 

 mm. long in flower, 7-9 mm. long in fruit, canescent. Incl. var. affinis (R. Br.) 

 L. Benson. 



On seepage slopes below snow banks and in wet meadows, in Ariz. (Coconino 

 Co.), June-July; circumpolar, Greenl., Nfld. and Lab. to Alas., s. to Ariz. 



18. Ranunculus abortivus L. 



Glabrous terrestrial biennial with filiform roots, sometimes enlarged at the 

 base; stems erect or suberect, not rooting, to about 5 dm. long, branching, fistu- 

 lous, striate; basal leaves with petioles 4-11 cm. long, simple or rarely some 

 trifoliate, reniform to orbicular in outline, to 9 cm. long and 1 dm. broad, usually 

 much smaller, crenulate to crenate or crenately lobed; stipular leaf bases scarious, 

 1-2 cm. long; cauline leaves alternate, sessile, the bracts deeply once- or twice- 

 parted to form 3 or 5 elliptic lobes or rarely cuneate or obovate and apically 

 shallowly lobed or toothed; flowers as many as 50, with pedicels to 15 mm. long in 

 flower and 9 cm. long in fruit, glabrous; sepals 5, yellowish, spreading, elliptic, 

 3-5 mm. long, 1-2 mm. broad, glabrous, deciduous after anthesis; petals 5, elliptic, 

 2.5-3.5 mm. long, 1.3-2 mm. broad, the glabrous nectary scale forming a pocket 

 and emarginate; stamens 15 to 20; achenes 10 to 35 in an ovoid head 3-6 mm. 

 long and 2.5-4 mm. in diameter, discoid-obovate, 1.4-1.6 mm. long, smooth, 

 glabrous, the margin inconspicuous, the beak minute; receptacle fusiform- 

 cylindroid, about 2 mm. long in flower, 2-4 mm. long in fruit, sparsely villous or 

 sometimes glabrous. 



In moist, marshy or swampy ground, in mud on edge of pools and lakes, 

 and in open areas or rich woodland in s.e. Okla. (McCurtain Co.) and e. Tex., 

 Mar.-May; transcontinental from N.S. to Alas., s. to Wash., Colo., Tex. and Fla. 



19. Ranunculus glaberrimus Hook. 



Glabrous perennial; roots large and fleshy, 2-3 mm. thick; stems prostrate or 

 ascending, not rooting, 4-8 cm. long; 1- to 6-flowered; petioles 3-9 cm. long, 

 the stipular leaf bases usually 5 or rarely 20 mm. long; basal leaf blades simple 

 and entire or rarely compound and dissected, orbicular or ovate to elliptic or 

 oblanceolate, or the blade dissected but deltoid to reniform in outline, 2-5 cm. 

 long, 1-1.8 cm. broad, entire or 3- (or 5-) lobed at the apices or rarely dissected 

 triternately into narrow divisions, thick, proximally rounded or tapered and distally 

 rounded to acute; cauline leaves and bracts alternate, 3-parted or -divided or 

 rarely dissected, sessile; pedicels 1-4 cm. long in flower, 5-12 cm. long in fruit; 

 sepals dorsally lavender-tinged, spreading, elliptic, 5-8 mm. long, 3-5 mm. wide, 

 slightly pubescent dorsally, promptly deciduous; petals 5, or rarely more, yellow 

 or with age turning white, obovate, 6-15 mm. long, 5-10 mm. wide; nectary 

 scale nearly always ciliate, forming a cuneate-rectangular pocket 1.5-3 mm. 

 deep, truncate or 2-lobed, the apex sometimes free; stamens 40 to 60; achenes 

 75 to 150 in a large globose head 1-2 cm. in diameter, irregularly obovoid, 2 



945 



