398 BANUNCULACEAE (CROWFOOT FAMILY) 



flowers 1-1.8 cm. in diameter; sepals refiexed in anthesis ; head of fruit ovoid; 

 achenes small, flat, strongly margined, the faces sometimes a little warty ; style 

 short, erect. — Waste places, ballast, etc., Philadelphia and southw. (Adv. 

 from Eu.) 



25. R. pennsylvanicus L. f. (Bristly C.) Stout and erect from a usually 

 annual root, hirsute with widely spreading bristly hairs, leafy to the top, 4-6 dm. 

 hi,2:h ; leaves all ternately divided or compound, the stalked leaflets unequally 

 •J-cleft, sharply cut and toothed, acute ; flowers inconspicuous ; sepals reflexed ; 

 carpels obscurely margined, in Si short-cylind7ic head ; receptacle cylindro-conical. 

 — Wet places. June-Aug. (Asia.) 



26. R. Macounii Britton. Kesembling the last, but the ascending or reclin- 

 ing stems few-leaved, rarely if ever rooting, not always hirsute ; petals (about 



6 mm. long) surpassing the hardly reflexed and soon decidu- 

 ous calyx ; achenes with a stout straight beak, in a globose 

 or ovoid head ; receptacle thick, ohovoid. (i?. hispidns Man. 

 ed. 6.) — Que. to L. Superior, "la.," and westw. Fig. 730. 

 27. R. BULBosus L. (Bulbous C. or B.) Hairy ; stem 

 78(1. II. Macounii. (3 dm. high) erect from a hiilh-like haye ; radical leaves 

 Flower xVt- 3-divided ; the lateral divisions sessile, the terminal stalked 



Carpel x 4i^. and 3-parted, all wedge-shaped, cleft and toothed; ptduncles 



furrowed ; petals round, wedge-shaped at base ; calyx re- 

 flexed ; carpels tipped with a very short beak. — Fields ; very abundant only in 

 e. X. E. ; rare westw. May-July. — Leaves appearing as if pinnate. Petals 

 often 6 or 7, deep glossy yellow, the corolla more than 2.5 cm. broad. (Nat. 

 from Eu.) 



28. R. ACRis L. (Tall C. or B.) Hairy ; stem erect (6-9 dm. high) ; leaves 

 o-divided ; the divisions all sessile and 3-cleft or parted, their segments cut into 

 lanceolate or linear crowded lobes ; peduncles not furrowed ; petals obovate, 

 much longer than the spreading calyx. — Fields; common, especially eastw. 

 June-Aug. — Flowers nearly as large as the last, but not so deep yellow. 

 (Nat. from Eu.) Var. Steveni (Andrz.) Lange. Leaf-segments broadly ob- 

 lanceolate or even obovate-cuneate. — Moist meadows, N. E. and northeastw. ; 

 not rare. (Nat. from Eu.) 



* * Achenes beset vnth rough points or small prickles ; annuals. 



20. R. muricItus L. Nearly glabrous ; lower leaves roundish or ren if orm, 

 3-lobed, coarsely crenate ; the upper 3-cleft, wedge-form at the base ; petals 

 longer than the calyx; carpels fl.at, spiny -tuberculate on the sides, stroni;ly 

 beaked, surrounded with a wide and sharp smooth unarmed margin. — Wet 

 places, e. Va. and southw. (Nat. from Eurasia.) 



30. R. ARVENSis L. Similar to the preceding, but segments of the cauline 

 leaves more narrow and acute ; carpds armed on the thick border as well as the 

 surfaces. — Waste places, N. J. to O. (Sparingly adv. from Eu.) 



31. R. parvifl6rtis L. Hairy, slender and diffuse ; lower leaves roundish- 

 cordate, 3-cleft, coarsely toothed or cnt ; the upper 3-5-parted ; petals not longer 

 than the calyx; carpels minutely hispid and rough, beaked, narrowly margined. 

 — Waste places, etc., Md. and Va. to Fla. and Tex. (Nat. from Eu.) 



2. MYOSURUS [Dill.] L. Mouse-tail 



Sepals 5, spurred at the base. Petals 5, small and narrow, raised on a slen- 

 der claw, at the summit of which is a nectariferous hollow. Stamens 5-20. 

 Achenes numerous, somewhat 3-sided, crowded on a very long and slender spike- 

 like receptacle (wlience the name, from yuOs, a mouse, and ovpd, a tail), the seed 

 suspended. — Little annuals, with tufted narrowly linear-spatulate root-leaves, 

 and naked 1 -flowered .sca])es. Flowers small, greeni.sh. 



1. M. minimus I.. Fruiting spike 2-5 cm. long; achenes quadrate, blunt. — 

 Alluvial ground, etc.. 111. to Assina., N, Mex., and Fla.; also at Belleville, Ont. 

 (Maronn) ; and re[)orted from e. Va. (Eu.) 



