198 RANUNCULACEAE 



1-16, 2-35 mm. long, having a usually short claw, provided at the base of the blade with 

 a nectariferous pit usually covered by a scale, the blade rarely reduced. Stamens 10 to 

 many, very rarely fewer. Pistils 5 to many, the single ovule attached near the base of 

 the cell. Achenes capitate or spicate; turgid or flattened; smooth, papillate, or echinate, 

 striate, or with transverse ridges on the faces ; glabrous or hairy ; nearly always tipped 

 with an elongated beak ; coat firm and strong, or sometimes thin and loose, rarely utricular. 

 [Name diminutive of Rana, Latin for frog. Applied by Pliny because the majority of 

 species grow in marshy or wet places where frogs are abundant.] 



Species about 250, in nearly all frigid and temperate regions and in the mountains in the tropics. Type 

 species, Ranunculus acris L. 



Achenes or utricles not transversely ridged (except in typical R. sceleratus of the Section Hecatonia) ; petals 

 usually glossy, yellow or rarely red, white, or greenish; commonly palustrine or terrestrial. 

 Sepals deciduous during or soon after anthesis; fruits not utricular; petals yellow or rarely white or 

 greenish or dorsally red. 

 Pericarp not striate or nerved, thick and firm (Subgenus Euranunculus). 

 Leaves (either the cauline or the basal) lobed, parted, or divided. 

 Achenes smooth, sometimes hairy. 



Styles and achene beaks present, the achene not corky-keeled and not with corky 

 thickening on the margin of the body; nectary scale ventral to the nectary, cover- 

 ing it, apically truncate or rounded. 

 Nectary scale free laterally for at least two-thirds its length, not forming a pocket; 

 dorsoventral measurement of the achene 3— IS times the lateral; receptacle in 

 fruit (in most species) elongated only 1—3 times its length in anthesis; sepals 

 usually not lavender- or purple-tin.eed. I. Chrysanthe. 



Nectary scale attached to the petal laterally and forming a pocket; dorsoventral 

 measurement of the achene 1-2.5 times the lateral; receptacle in fruit 3-15 times 

 its length in anthesis; sepals always tinged dorsally with purple or lavender. 



III. Epirotes. 



Styles and achene beaks practically lacking or otherwise the achene with a corky keel 

 or with corky thickening on the margin of the body; nectary scale with the gland in 

 a pocket on its ventral surface or else the scale forked and prolonged anteriorly on 

 the surface of the petal or surrounding the gland; aquatic or palustrine. 



V. Hecatonia. 



Achenes covered with spines, hooks, or papillae or with papillae produced into hooked hairs; 

 dorsoventral measurement of the achene 3-6 times the lateral ; receptacle in fruit 1—3 

 times its length in anthesis. II. Echinella. 



Leaves (both cauline and basal) entire, dentate, serrulate, or wavy; dorsoventral measurement 

 of the achene not more than twice or thrice the lateral. IV. Flammula. 



Pericarp striate, the nerves 3 or more on each face, these sometimes branched, ovary wall thin and 

 usually fragile (Subgenus Cyrtorhyncha) . 

 Petals larger than the sepals; fruiting receptacle elongated to several times its length in anthesis, 

 cylindrical or long-ovoid ; nectary scale overarching the nectary, truncate, the margins free 

 from the blade of the petal; stolons present. VI. Halodes. 



Petals smaller than the sepals; receptacle but slightly elongated in fruit, not cylindrical; nectary 

 scale forming a pocket, forked, its lateral margins attached to the blade of the petal; 

 stolons never present. 



Sepals yellow; blades of the petals 7-8 mm. long, yellow. VII. Arcteranthis. 



Sepals white; blades of the petals 1-3 mm. long, yellowish or greenish. 



VIII. Pseudaphanostemma. 

 Sepals persistent in fruit; fruit utricular; petals red on both sides (Subgenus Crymodes). 



IX. EUCRYMODES. 



Achenes roughly transversely-ridged; petals not glossy, white, the claws sometimes yellow; aquatic plants 

 (Subgenus Batrachium). X. Eubatrachium. 



I. Chrysanthe. 



Fruiting receptacle not more than twice as long as the flowering. 

 Receptacle glabrous. 

 Sepals spreading. 



Stems not rooting; leaves appearing palmately 5-parted by the forking of the two lateral lobes. 



1. R. acris. 

 Stems rooting at the nodes; leaves obviously 3-lobed, -parted, or -divided. 



2. R. repens. 

 Sepals reflexed. 



Stem base a conspicuous, bulb-like subterranean thickening. 3. R. bjilbosus. 



Stem base not bulbous. 



Petals large and conspicuous, at least twice the length of the sepals. 



Achenes 3.5 or commonly 4—5 mm. long; petal blades 1-2 (or in a variety 2-2.5) 



times as long as broad. 4. R. canus. 



Achenes 1—3 or rarely 3 . 5 mm. long. 



Petals 5-6, rarely 7-9 or 12, the blades 1-2 or rarely 2.5 times as long as broad. 



5. R. occidentalis. 

 Petals 9-16 or 26, rarely fewer, the blades 2-2.5 times as long as broad. 



6. R. californicus. 

 Petals minute, 3 mm. long or less, shorter than the sepals. 7. R. Bongardii. 



Receptacle covered with bristly hairs; achene beaks straight, at least as long as the bodies; sepals reflexed. 

 Herbage glabrous or practically so; petals emarginate. 8. R. Bloomeri. 



Herbage markedly hispid; petals not emarginate. 9. R. orthorhynchus. 



Fruiting receptacle greatly enlarged and elongated. 



Petals slightly longer than the sepals; stems usually rooting at the nodes; head of achenes ovoid, 7-9 mm. 



long. 10. R. Macounii. 



Petals not more than half the length of the sepals; stems never rooting; head of achenes cylindrical, 11-17 

 mm. long. 11. R, pennsylvanicus. 



