RANUNCULACEAE 519 
17. BATRACHIUM S. F. Gray. Perennial aquatic or ditch herbs. Leaf- 
es yao compressed, trans- 
verse-wrinkled, often nearly or quite besten “Spr — ( WATER-CROWFOOTS. 
ROGWEEDS.)—About 20 species, of wide geographic eee 
Leaf-segments a mm. long, firm: blades scarcely collapsing when withdrawn 
1. B. trichophyllum. 
from the wate 
long, flaccid: blades collapsing 
Leaf-segments 15 -90 mm. 
when 2. B. flaccidum. 
withdrawn from the water. 
1. B. ia pac ig ar i sons osch. Leaves 
firm, 3-5 em. long, t enis d mostly 10— 
15 mm. long; MCN shore and broad, pubes- 
cent: petals 5-8 mm. long: head of achenes 
4—5 mm. in diameter. Ese eta aquatilis 
trichophyllus A. Gra ay|—WnB WATER- 
CROWFOOT.)—Ponds, springs, and spring- 
dec various x ox N. C. to Calif. and 
S Can.—(Mez., O. W.) | 
e 
more slender PUE and very lon m slender 
segments.—Streams, various ne N. C. 
to Calif. Wash., S ‘Can n. and Mass.—(Mez., 
0. W. 
18. RANUNCULUS [Tourn.] L. Annual or perennial herbs. Leaf-blades 
entire, lobed, or divided. Flowers solitary or variously disposed. Sepals mostly 
, deciduous. Petals as many as the sepals or more, or rarely fewer, each with 
api or scale at the base. Carpels several or numerous. Achenes generally 
flattened, smooth, papillose, or echinate b CR da 275 species, most abundant in 
temperate and cold regions.—BUTTERCUPS CROWFOOTS. Gorp-c CUPS. 
Aquatic plants: submerged leaves with dissected blades; SURE leaves with lobed 
blades I. MULTIFIDI. 
Terrestrial or mud-inhabiting plants: leaves with entire, toothed, ` 
lobed, or divided blades i 
Leaf-blades linear to NAT entire, crenate or denticulate. II. FLAMMULAE. 
Leaf- A at least some of them, lobed or divided. 
Achene turgid, marginless. III. ABORTIVI. 
r less flattened, margined or variously 
Rene more o 
u E 
ro 
Achene smoo 
Achene- beak distinctly hooked. . IV. RECURVATI. 
V. REPENTES. 
Achene-beak straight or nearly SO. — 
Achene variously roughened. MEE VI. MURICATI. 
I. 
Lower oe with finely dissected, pia re . &-eleft 
blades 1. R. delphinifolius. 
II. FLAMMULAE 
Annuals : achene beakies a 
Head of fruit cylin drie to ellipsoid. 2. R. tener. 
Hen o fruit A to ovoid. 
hene papil 8. R. Lindheimeri. 
p smoo 
Petals mostly less than 3 mm. long. 4. R. pusillus. 
Petals mostly over 3 mm. long. PT 
Petals less than 6 mm. long, m mostly 5: .5. R. oblongifolius. 
tals over 6 mm. long, mostly more than 5: 6. R. mississippiensis. 
7. R. obtusiusculus. 
Pe 
Perennial : stems creeping: achene with a subulate beak. 
