(Apache, Navajo. Coconino, Greenlee, Cochise and Santa Cruz cos.), Apr.-July; 

 also Calif, and s. into Mex. 



22. Ranunculus laxicaulis (T. & G.) Darby. Fig. 462. 



Glabrous palustrine annual with filiform roots; stems erect or reclining, root- 

 ing adventitiously at only the lowest nodes, 1-5 dm. long, freely branching, fistu- 

 lous; stem and axis of panicle often proliferating late in season by flabelliform 

 leafy offshoots; basal leaves with petioles 1-7 cm. long or longer when in water, 

 simply ovate to oblong, to 45 mm. long. 6-18 mm. broad, dentate to serrulate or 

 entire, truncate or rounded at base, truncate or obtuse at apex; the stipular leaf 

 bases about 1 cm. long; upper cauline leaves alternate, sessile, linear or lanceolate 

 to oblanceolate or very narrowly elliptic, acute, 15-35 mm. long, 2-6 mm. broad, 

 dentate; pedicels to 2 cm. long in flower and 6 cm. long in fruit; sepals 5, 

 greenish-yellow, spreading, ovate, 1.5-3 mm. long, about 1.5 mm. broad, glabrous 

 or sparsely hairy, promptly deciduous; petals 5 or rarely as many as 10, yellow, 

 3-9 mm. long, 1.5-2.5 mm. broad; nectary scale glabrous, forming a pocket 

 0.3-0.5 mm. long, truncate or prolonged a little on the margins; stamens 10 to 

 30; achenes 15 to 50 in a hemispheroidal head 2 mm. in radius or an ovoid head 

 2-4 mm. long and 2-2.5 mm. in diameter, obovate to subglobose, 0.6-0.7 mm. 

 long, smooth and glabrous, the margin inconspicuous, the style about 0.5 mm. 

 long; receptacle pyriform or spheroid, 1.5-2 mm. long in flower, 1.5-3 mm. 

 long in fruit, glabrous. R. texensis Engelm., R. pusillus of auth., not Poir. 



Boggy shores of lakes, in depressions, ditches, cypress ponds and marshes in 

 e. Okla. {Waterfall) and s.e. Tex., Mar.-June; from Fla. to Tex., n. to Conn., 

 Ind., 111., Mo. and Kan. 



23. Ranunculus pusillus Poir. Fig. 456. 



Glabrous palustrine annual with filiform roots; stems reclining, usually rooting 

 at the lowest nodes, 1-5 dm. long, freely branching, fistulous; basal and lower 

 cauline leaves with petioles 1-6 cm. long, simple, oblong to ovate or rarely 

 cordate, to 5 cm. long. 5-15 mm. broad, entire or a little irregular, truncate or 

 rounded at base, truncate to rounded or acute at apex, the stipular leaf bases 

 to 1 cm. long; upper cauline leaves alternate, sessile, linear or lanceolate to ob- 

 lanceolate or very narrowly elliptic, 1-5 cm. long, 2-5 mm. broad, entire or 

 sometimes dentate; pedicels to 15 mm. long in flower and 6 cm. long in fruit, 

 glabrous; sepals 5, greenish-yellow, spreading, ovate, 1-2 mm. long, 0.8-1 mm. 

 broad, glabrous or sparsely hairy, promptly deciduous; petals 1 to 3 or rarely 5, 

 yellow, obovate, 1.5-2.5 mm. long, 1 mm. broad; nectary scale glabrous, forming 

 a pocket 0.2 mm. deep, truncate; stamens 5 to 10; achenes as many as 125 in 

 a hemispheroid head about 4 mm. in diameter or an ovoid head 2-4 mm. long 

 and 2-2.5 mm. in diameter or a cylindroid head 5-8 mm. long and 2-3 mm. 

 in diameter, oblong-obovate, about 1 mm. long, smooth (with fine reticulations) or 

 slightly or markedly papillate, glabrous, the margin inconspicuous, the style in 

 anthesis 0.1-0.2 mm. long, the achene beak 0.1-0.2 mm. long; receptacle pyri- 

 form or spheroid, 1.5-2 mm. long in flower, 1.5-3 mm. long in fruit, glabrous. 

 Incl. var. angustifoHus (Engelm.) L. Benson, R. tener Mohr. 



In shallow water and mud of ditches, marshes, bogs, seepage areas and ponds 

 in prairies, open woods and thickets in Okla. (McCurtain, Marshall and John- 

 ston cos.) and the e. fourth of Tex., w. to Burnet Co., Mar.-May; from Calif, 

 to Mo. and N. Y. s. to Tex. and Fla. 



24. Ranunculus sceleratus L. Cursed buttercup. Fig. 463. 



Glabrous or rarely hirsute palustrine or rarely aquatic annual or short-lived 

 perennial; stems erect, rarely rooting, to 1 m. long, profusely branching, fistulous, 



949 



