6j2 FLORA. 



4. Hydrocotyle Americana L. American Marsh-pl... ./wort. (I. F. f. 

 2706.) Stems creeping, often bearing small tubers; leaves reniform, 2-5 cm. wide, 

 with shallow lobes; umbels sessile or very nearly so, 1-5-flowered; pedicels less 

 than 2 mm. long; fruit slightly more than 1 mm. broad and nearly as high, the 

 ribs all filiform. In wet places, N. S. to Minn., Penn. and N. Car. June-Sept. 



5. Hydrocotyle ranunculoides L. f. Floating Marsh-pennywort. 

 (I. F. f. 2707.) Stem usually floating, rooting from the nodes, 1.5-6 dm. long. 

 Petioles elongated, weak; leaves reniform, 2-5 cm. wide, 3-7-cleft, the lobes cre- 

 nate; peduncles much shorter than the petioles, recurved in fruit; umbels 5-10- 

 flowered; fruit nearly orbicular, about 3 mm. broad, the ribs obscure and filiform. 

 In ponds and swamps, Penn. to Fla., near the coast, west to Tex.; Ore. to L. Cal. 

 Also in Cent, and S. Am., Abyssinia and Italy. June-Sept. 



2. CENTELLA L. 



Perennial herbs (some African species shrubby), ours with prostrate stems root- 

 ing and sending up tufts of long-petioled leaves at the nodes, together with 1-3 

 long-rayed umbellets of small white flowers, the true umbel sessile. Petiole-bases 

 sheathing. Bracts of the involucels 2-4, mostly prominent. Calyx-teeth none. 

 Disk flat, or slightly concave. Styles filiform. Fruit somewhat flattened laterally, 

 rather prominently ribbed, the ribs mostly anastomosing; oil-tubes none. [Latin, 

 diminutive of centrum, a prickle.] About 20 species, of wide distribution, most 

 abundant in S. Africa. 



1. Centella repanda (Pers.) Small. Ovate-leaved Marsh-pennywort. 

 (I. F. f. 2708.) Stem 2-15 cm. long. Petioles 0.5-3 dm. long, sometimes pubes- 

 cent; blades ovate, rather thick, rounded at the apex, broadly cordate at the base, 

 not peltate, 2-4 cm. long, repand-dentate; pedicels much shorter than the leaves, 

 1-5 cm. long; umbellets capitate, 2-4- flowered, subtended by 2 ovate bracts; flow- 

 ers nearly sessile; fruit 4-5 mm. broad, about 3 mm. high, prominently ribbed and 

 reticulated. In wet grounds, Md. to Fla., west to Tex. Also in tropical Am., 

 Asia, Africa and Australia. June-Sept. {Hydrocotyle repanda Pers.] 



3. SANICULA L. (See Appendix.) 

 Perennial or biennial mostly glabrous herbs, with palmately 3-7-foliolate or 

 pinnatifid leaves and small flowers in compound generally few-rayed umbels. Um- 

 bellets globose. Involucre foliaceous; involucels small. Calyx-lobes mostly per- 

 sistent. Petals obovate, or narrower, emarginate. Disk flat. Fruit somewhat 

 flattened laterally, subglobose, covered with hooked bristles in our species. Car- 

 pels not ribbed; oil-tubes usually 5. [From the Latin, to heal.] About 20 

 species, natives of the north temperate zone, S. Am. and S. Africa. Besides the 

 following, about 10 others occur in the southern and western U. S. 



* Perennial: some staminate flowers in separate heads; styles longer than the bristles. 

 Petals and anthers greenish white; calyx-segments lanceolate, cuspidate; fruit 6 mm. 



lon s I. S. Marylandica. 



Petalsand anthers yellow ; calyx-lobes ovate, obtuse ; fruit 3 mm. long, or less. 



J 2. S. gregaria. 



* * Biennial; staminate flowers never in separate heads; styles shorter than the 



bristles. 



Leaves t-s-divided; pedicels of staminate flowers 2 mm. long; fruit less than 4 mm. 



, J 3 3. S. Canadensis. 



Leaves vfoliolate: pedicels of staminate flowers 4 mm. long; fruit 6 mm. long or more. 

 * w 4. S. trifoliata. 



1. Sanicula Marylandica L. Sanicle. Black Snake-root (L F. f. 

 2664.) Rather stout. 4-12 dm. high, topped by a 2-4-rayed umbel. Leaves 

 firm blui I he basal long-petioled, the upper sessile, 5-7-parted; segments 



4 k cm long obovate to oblanceolate, serrate or dentate, often incised; involucral 

 leaves much smaller, j-cleft; involucel-bracts rarely 2 mm. long; pedicels of 

 staminate Bowers 4 nun. long; calyx 2 mm. long, parted into subulate segments; 

 petals little exceeding the calyx; fruil sessile, ovoid, the slender recurved styles 

 n the stout bristles; oil-tubes 5, large; seed furrowed dorsally. In rich 

 , New£ to Alberta, Ga. and Colo. May-July. 



