402 RANUNCULACEAE (CROWFOOT FAMILY) 



white ; head of fruit cylindrical (2-3.5 cm. long). Rocky woods and dry bar- 

 rens, w. Me. to Sask., s. to N. J., Pa., 111., Mo., Kan., N. Mex., and Ariz. 

 May-July. 



6. A. riparia Fernald. Less conspicuously pubescent ; leaflets thinner, 

 greener, less strongly veined ; those of the involucre lanceolate, cuneate at the 

 base; sepals 5, large (1.6 cm. long)", obtuse, white or rarely reddish, mostly 

 petaloid ; head of fruit subcylindric, the styles suberect. Calcareous river- 

 banks, etc., Gasp6 Co., Que., to Alberta, s. to Me., w. Ct., e. Pa., and w. N. Y. 

 May, June. 



7. A. virginiana L. Loosely pubescent or glabrate ; involucral leaves 3, 3- 

 parted ; their divisions ovate-lanceolate, pointed, cut-serrate, the lateral 2-parted, 

 the middle 3-cleft ; peduncles elongated, the earliest naked, the others with a 2- 

 leaved involucel at the middle, repeatedly proliferous ; sepals 5, acute, greenish 

 (in one variety white and obtuse) ; head of fruit ovoid or thick-cylindric, the 

 styles divergent. Woods and meadows, centr. Me. to Minn. , and south w. 

 June-Aug. Plant 0.6-1 m. high ; the upright peduncles 1.5-3 dm. long. 



* * Achenes naked, orbicular, compressed, wing-margined ; sepals 5, obovate ; 



involucre sessile. 



8. A. canad6nsis L. Hairy, rather low ; primary involucre 3-leaved, bear- 

 ing a naked peduncle, and soon a pair of branches or peduncles with a 2-leaved 

 involucre at the middle, which branch similarly in turn ; their leaves broadly 

 wedge-shaped, 3-cleft, cut and toothed ; radical leaves 5-7-parted or cleft ; se- 

 pals white (1.2-1.8 cm. long); head of fruit spherical. (A. pennsylvanica L.) 

 River-banks and prairies, e. Que. to Assina., s. to N. S., centr. Me., w. N. E., 

 N. J., Pa., Great Lake region, Mo., Kan., and Col.; escaped from cultivation 

 elsewhere. 



* * * Achenes rather few, nearly naked, ovate-oblong ; stems slender, \-flowered; 



leaves radical. 



9. A. quinquef61ia L. (WOOD A.) Low, smoothish ; stem perfectly simple, 

 from a thick-filiform whitish or brown rootstock ; involucre of 3 long-petioled 

 trifoliolate leaves, their leaflets wedge-shaped or oblong, and laciniately toothed 

 or the lateral ones 2-parted ; a similar radical leaf in sterile plants solitary from 

 the rootstock ; peduncle not longer than the involucre ; sepals 4-7, oval, white, 

 or tinged with purple outside ; carpels only 15-20, oblong, with a hooked beak. 

 (A. nemorosa of Man. ed. 6, not L.) Margin of woods. Apr., May. A 

 delicate vernal species ; the flower 2 cm. broad. 



The European A. NEMOR6SA L., with thicker blackish rootstock, has been 

 found as an escape from cultivation in e. Mass. (Sears}. 



10. A. trifblia L. Similar in habit, somewhat stouter ; the leaflets of the 

 involucre lanceolate to ovate, 2-3 cm. broad, rather regularly serrate, not in- 

 cised ; flower 2.8-3.5 cm. in diameter ; sepals oval, white. Woods, mts. of s. 

 Pa. to Ga. (Eu.) 



9. CLEMATIS L. VIRGIN'S BOWER 



Perennial herbs or vines, mostly a little woody, and climbing by the bending 

 or clasping of the leafstalks, rarely low and erect. (KX^aT/s, a name of Dios- 

 corides for a climbing plant with long and lithe branches.) 



1. FLAMMULA DC. Flowers cymose-paniculate, rather small, in our spe- 

 cies dioecious or the pistillate with some sterile stamens. Sepals petaloid, 

 whitish, spreading, thin. Petals none. Anthers short, blunt. 



1. C. virginiana L. Leaves normally 3-foliolate ; leaflets ovate, acute, thin, 

 dark green above, when young silky-villous beneath, in age more or less com- 

 pletely glabrate, heart-shaped at the base, variously few-toothed. River-banks, 

 etc., common; climbing over shrubs. July, Aug. A variation, found in the 

 lower Missouri Valley and having more persistent pubescence and " marginless " 

 achenes, has been described as C. missouriensis Rydb. 



