442 KANUNCULACEAE 



** Plants not stoloniferous : foliage copiously pubes- 

 cent, except sometimes in age. 

 Stems with silky or appressed pubescence. 

 Achenes flattened, with persistent subulate 



styles. 16. R. fascicularis. 



Achenes tumid, with deciduous filiform styles. 17. R. apricus. 

 Stems with spreading pubescence. 



Achenes narrowly margined : style subulate, 



about as long as the achene-toody. 18. JR. hispidus. 



Achenes broadly margined : style triangular, 



about y z as long as the achene-body. 19. R. cuneiformis* 



b. Corollas 3 cm. broad or larger : petals 7-16 : head of 



fruit oblong or cylindric. 20. R. macranthus. 



B. Achenes variously roughened. 



Achenes more or less papillose ; beak minute. 



Corollas 2-3 cm. broad : achenes sparingly papillose near the edges. 21. -R. parvnlus. 

 Corollas 2-5 mm. broad : achenes papillose all over. 22. R. parviflorus. 



Achenes muricate or spiny ; beak about > as long as the body. 23. R. muricatus. 



1. Ranunculus delphinifolius Torr. Aquatic or partly emersed. Foliage glabrous 

 or pubescent : stems branching, sometimes several dm. long : submersed leaf-blades short- 

 petioled, 2.5-7.5 cm. long, repeatedly divided into capillary segments ; emersed leaf- 

 blades 1.5-5 cm. broad, petioled or the upper nearly sessile, 3-5-divided, the divisions 

 cleft into linear or cuneate segments : corolla yellow, 18-36 mm. broad : petals 5-8, much 

 longer than the sepals : head of fruit globose or oblong, 6-10 mm. long : achenes less than 

 2 mm. long, callous-margined, each tipped with a straight persistent beak % its length or 

 more. [Ranunculus multifidus Pursh, not Forsk. ] 



In ponds, Massachusetts and Ontario to Michigan, North Carolina and Missouri. Summer. 



2. Ranunculus t6ner Mohr. Foliage glabrous. Stems ascending or erect, 0.5-6 dm. 

 tall, more or less branched, often tufted, rarely rooting : basal leaves few ; blades ovate to 

 ovate-lanceolate, 1-2 cm. long, entire or undulate, slender-petioled ; stem-leaves conspicu- 

 ously different from the basal, the blades oblong, lanceolate or linear, undulate, repand or 

 denticulate : flowers inconspicuous, slender-pedicelled : petals 1-3 or rarely 5, yellow, 

 1-1.5 mm. long: stamens 5-10 : head of fruit oblong-cylindric, 3-4 mm. long: achenes 

 suborbicular, lenticular but swollen, 0.6-0.8 mm. long, slightly margined, the faces mi- 

 nutely tuberculate. 



In low grounds, Alabama to Louisiana and Texas. Spring. 



3. Ranunculus pusillus Poir. Foliage glabrous. Stems slender, weak, branching, 

 1.5-3 dm. high : leaf-blades entire or denticulate, the lower oblong or ovate, on long 

 petioles, the upper narrower, lanceolate or linear, short-petioled or sessile : corolla yellow, 

 4-6 mm. broad : petals few, often barely exceeding the sepals in length : stamens 1-10 : 

 head of fruit, globose, 4 mm. broad : achenes fully 1 mm. long, beakless, each merely 

 tipped with the persistent style-base. 



In marshes, southern New York and Pennsylvania, mostly near the coast, to Florida and through 

 the Gulf States to Texas and Missouri. Spring and early summer. The small form of the southern 

 border of the United States with more prominently papillose achenes, is -R. pusillus Lindheimeri 

 (Engelm.) A. Gray. 



4. Ranunculus oblongif olius Ell. Foliage glabrous or pubescent. Stems branched 

 above, erect or ascending, 2-5 dm. high : leaf-blades entire or denticulate, mainly oblong 

 or oblong-lanceolate, 2-7.5 cm. long, the lower on long petioles, the upper narrower, lanceo- 

 late or linear: corolla yellow, 10-12 mm. broad : petals 5, much exceeding the sepals: 

 stamens numerous : head of fruit 4 mm. broad : achenes beakless, each merely tipped with 

 the style-base. 



In swamps, Virginia to southern Illinois and Missouri, Florida and Texas. Spring and summer. 



5. Ranunculus obtusiusculus Kaf. Foliage glabrous. Stems stout, hollow, 3-9 

 dm. long, ascending, rooting from the lower nodes, sometimes nearly 2.5 cm. thick at the 

 base : leaf -blades linear or lanceolate, 8-15 cm. long, denticulate or entire, all but the 

 uppermost on broad petioles, each clasping the stem by a broad base : corolla yellow, 12- 

 16 mm. broad, or smaller : petals 5-7, much exceeding the sepals : head of fruit globose or 

 slightly elongated, 10-12 mm. in diameter : achenes compressed, 1 mm. long, subulate- 

 beaked, but the beak early deciduous. [Ranunculus ambigens S. Wats.] 



In marshes, Maine and Ontario to Minnesota, Georgia and Missouri. Summer. 



6. Ranunculus Harveyi (A. Gray) Britton. Foliage glabrous. Stems erect, 

 slender, branched, 1.5-5 dm. tall : leaf-blades thin, those of basal and lower stem-leaves, 

 lonsr-petioled, reniform or suborbicular, obtusely crenate or somewhat lobed, 1-2 cm. wide, 

 cordate, or some of them truncate at the base, those of the upper stem-leaves sessile or 

 nearly so, deeply 3-cleft or 3-parted into linear or narrowly oblong entire or few-toothed 

 obtuse segments : corolla bright yellow, 12-18 mm. broad : petals 4-8, oblong, 4-5 times a& 



