BUTTERCUP FAMILY 533 



Leaves (or some of them) toothed, lobed or divided. 



Herbage glabrous or nearly so; aehenes thick or plump. 

 Perennials; low plants; alpine or northern. 



Basal leaves nearly or quite as broad as long, rounded or truncate at base, 



3-lobed at apex or entire 7. E. glaberrimus. 



Basal leaves broader than long, subcordate, 3 (or 5) -parted and coarsely 



toothed 8. E. eschsclwltzil. 



Annuals; stems fistulous _ 9. E. soeleratus. 



Herbage pubescent or hirsute; leaves lobed or divided, mostly compound; perennials. 

 Beak of the aehenes commonly curved, much shorter than the body, rarely as long. 

 Stems commonly rather coarse, mostly erect and rather tall; aehenes strongly 

 flattened. 



Corolla pale or whitish, very small; beak of achene like a grab-hook 



10. E. bongardii. 

 Corolla golden, showy; sepals reflexed, 



Beak deltoid, slightly curved at the acute tip ; petals 5 to 10 



11. E. canus. 

 Beak narrowly or broadly subulate, not deltoid. 



Petals 9 to 16; beak very short, stoutish, rather closely recurved. 



12. E. oalifornicus. 

 Petals 5 or 6; beak rather slender, falcate-curved but more or less 



erect 13. E. ocoidentalis. 



Stems creeping or reclining; aehenes roundish or turgid, the beak curved or, 



if straight, at least hooked at tip; sepals not reflexed. 

 Corolla showy; aehene margined; beak somewhat recurved ..14. E. repens. 

 Corolla small; aehene not margined; beak nearly straight ..15. E. macounii. 

 Beak of the aehenes straight, as long as the body; sepals reflexed; stems spread- 

 ing or ascending. 

 Leaflets toothed or laeiniate. 



Petals 5, emarginate ; leaflets crenate, mostly not lobed ....16. E. bloomeri. 



Petals 5 to 8, rounded at apex; leaflets deeply 3-cleft or laeiniate 



17. E. orthorhynchits. 



Leaflets or their divisions with entire margins, not serrate or laeiniate 



18. E. marmorarius. 

 Aehenes prickly or with stiffish hooked hairs; annuals. 



Flowers minute; aehenes with hooked hairs; delicate plant 19. E. hebecarpus. 



Flowers medium; aehenes spiny -muricate, with raised border. 



Leaves cleft into 3 to 5 lobes, the lobes toothed; border of achene beveled, not 



spiny 20. E. muricatus. 



Leaves deeply 2 or 3 times divided; border of achene spiny 21. E. arvensis. 



2. Aehenes utricular or with a thin coat; perennials. 



Leaves much . dissected ; flowers pink ; aehenes strongly inflated. Subgenus CRYMODES 



22. E. andersonii. 



Leaves cordate, lightly crenate; flowers yellow; aehenes thin-walled, striate; receptacle elon- 

 gated-oblong; stems creeping. Subgenus HALODES _ 23. E. cymbalaria. 



B. Nectar-bearing pit on petal claws naked; leaves or some of them filiform-dissected; 

 flowers white; aquatic. Subgenus BATBACHIUM. 



Leaves immersed, all filiform-dissected, or rarely some floating leaves 3-parted into broad 

 rounded lobes '. 24. E. aqvatilis. 



Leaves floating, with 3 broad divergent narrowly ovate lobes, or some submersed leaves capil- 

 lary-dissected 25. E. lobbii. 



1. R. delphinifolius Torr. YELLOW WATER CROWFOOT. Aquatic perennial; 

 stems fistulous, 1 to 2 feet long; leaves three or four times ternately dissected 

 into linear-filiform acuminate segments; flowers golden-yellow, showy (8 to 13 

 lines broad), on naked fistulous peduncles % to 2*4 inches long; petals 5 or 6, 

 broadly obovate ; scale of the nectary pit prolonged upwards into narrow or broad 

 wings attached by one edge to the petal and often with free tips, the whole 

 structure conspicuous, 14 to % as long as the petal, but apparently variable in 

 form and size; aehenes turgid, callous-margined at base and ventrally with a 

 tumid ridge, % line long, the subulate beak over half as long. 



