32(31). Petals narrow; sepals glabrous or thinly appressed-pubescent, some of 

 the basal leaves proxinially attenuate, acute to obtuse, at least some 

 basal leaves on each plant crenate, occasional leaves 3-lobed or 

 -divided 15. R. inamoenus. 



32. Petals broadly cuneate-obovate; sepals pilose-tomentose; basal leaves proxi- 

 mally cordate 17. R. pedatiftdus. 



1. Ranunculus repens L. Creeping buttercup. Fig. 455. 



Hirsute terrestrial or palustrine perennial; stems prostrate to suberect, rooting 

 at least at the lower nodes, commonly but not always with some stoloniferous, to 

 9 dm. long, branching, not fistulous, hirsute to glabrous or nearly so; leaves com- 

 pound, deltoid-cordate in outline, to 11 cm. long and 13 cm. broad, usually much 

 smaller, pinnate with 3 sessile or petiolulate leaflets that are cuneate to subtruncate 

 or sometimes rounded or subcordate at the base and lobed and toothed (but acute 

 in outline) at apex, sometimes the leaflets tending to be rounded, the middle 

 petiolule to 4 cm. long, the lateral petiolule to 2 cm. long, the petioles 4-25 cm. 

 long, hirsute to subglabrous, the stipular leaf bases 6-20 mm. long; cauline leaves 

 alternate. like the basal; pedicels 2-10 cm. long in flower, 4-15 cm. long in fruit; 

 pubescent; sepals 5, greenish, spreading, 5-7 mm. long, 3-4 mm. broad, pilose, 

 promptly deciduous; petals 5 or rarely the staminodia forming a "double" flower, 

 cuneate-obovate, 7-13 mm. long, 5-10 mm. broad, the glabrous truncate nectary 

 scale free laterally for two thirds of its length and 1-1.3 mm. long; stamens 50 

 to 80, the number reduced in "double" flowers, achenes 20 to 25 in a subglobose 

 head 6-7 mm. in diameter, obovoid-discoid, 2.5 mm. long, smooth, glabrous, the 

 margin prominent, the recurved beak stout and 1 mm. long; receptacle subglobose- 

 ovoid, 1-2 mm. long in flower, 3 mm. long in fruit, pubescent or rarely glabrous. 



This Old World species sometimes occurs as an escape, especially the garden 

 form, var. pleniflorus Fern. It becomes established along stream courses, wet. 

 meadows, marshes and in wet springy places. 



2. Ranunculus acris L. Fig. 455A. 



Hirsute terrestrial perennials, the pubescence spreading or rarely appressed; 

 roots stout but not tuberous, 0.5-1 mm. thick; stems several, erect, not rooting, 

 5-10 dm. long, freely branching above, glabrous or sparsely hirsute; petioles 5-17 

 cm. long, hirsute, the stipular leaf bases 3-5 cm. long; basal leaf blades simple, 

 pentagonal in outline, 4-8 cm. long, 5-10 cm. wide, deeply 3-parted and again 

 lobed, appearing 5-parted by forking of the lateral primary parts, proximally 

 deeply cordate, distally rounded in outline, densely appressed-hirsute beneath, 

 more sparsely so above; cauline leaves alternate, petioled, the bracts of 3 linear 

 divisions sessile; pedicels 1-5 cm. long in flower, 4-12 cm. long in fruit, densely 

 pubescent; sepals 5. greenish, spreading, ovate, 4-7 mm. long, about 3 mm. wide, 

 densely pubescent dorsally, promptly deciduous; petals 5, obovate-cuneate, 8-14 

 mm. long, 6-10 mm. wide; nectary scale glabrous, free laterally for two-thirds of 

 its length, 1.2 mm. long, truncate; stamens 40 to 80; achenes 25 to 40 in a globose 

 head about 6 mm. in diameter, obovoid-discoid, 2-2.5 mm. long, 1.8 mm. dorso- 

 ventrally, 0.5 mm. laterally, smooth, glabrous, the margin conspicuous, keeled, 

 the recurved beak deltoid at base and 0.3-0.6 mm. long; receptacle pyriform, 1-2 

 mm. long in flower, 2.5 mm. long in fruit, glabrous. 



In water on edge of streams and ponds, in N. M. (Catron Co.) May-July; 

 an Old World species now widespread through much of N.A., especially in the 

 north. 



3. Ranunculus uncinatus D. Don. 



Hirsute or hispid to glabrous terrestrial annual or perennial; roots 0.5-1 mm. 

 thick; stems erect, not rooting, 3-10 dm. long, freely branching above, glabrous 



933 



