Fig. 574A: Hydrocotyle verticillata var. verticillata: a, habit, x i^; b, part of inflores- 

 cence, X 6; c, flower, x 10; d, fruit, x 12. (Courtesy of R. K. Godfrey). 



1. Leaves reniform, not peltate, the petioles attached in a sinus at one edge of 

 the blade 5. H. ranunculoides. 



1. Leaves peltate, the petioles attached to the middle of the blade (2) 



2(1 ). Flowers and fruits in a simple (not proliferous) umbel 1. H. umbellata. 



2. Flowers and fruits in a proliferous umbel or an interrupted spike (3) 



4. H. bonariensis. 



3(2). Inflorescence profusely branched 



3. Inflorescence usually unbranched or only bifurcate (4) 



4(3). Inflorescence often bifurcate; fruits sessile or subsessile 



2. H. verticillata var. verticillata. 



4. Inflorescence rarely bifurcate; fruits pedicellate 



3. H. verticillata var. triradiata. 



1. Hydrocotyle umbellata L. Ombligo de Venus. Fig. 573. 



Plants glabrous; stems slender to somewhat thickened, floating or creeping; 

 leaves orbicular-peltate, to 75 mm. in diameter, crenate or crenately lobed; petioles 

 mostly slender, to 40.5 cm. long, usually much shorter; peduncles usually exceed- 

 ing the leaves, to 35 cm. long; umbels simple, many flowered; rays to 2.5 mm. long, 

 spreading and reflexed; stylopodium depressed; fruit orbicular to ellipsoid, 1-2 mm. 

 long, 2-3 mm. broad, the dorsal surface acute, the dorsal and lateral ribs evident 

 and obtuse; strengthening cells lacking. 



In swampy areas in shallow water, bogs, edge of ponds, ditches, marshy ground 

 in Okla. {Waterfall) and in the e. half of Tex., Apr.-Oct.; from N.S., s. to Fla., 

 w. to Minn, and Tex.; also Ore., Calif., W.I. and from Mex., s. to S.A 



2. Hydrocotyle verticillata TTiunb. var. verticillata. Fig. 574A. 



Plants glabrous; stems filiform, creeping; leaves orbicular-peltate, to 6 cm. in 

 diameter, 7- to 14-veined, shallowly 8- to 13-lobed, the lobes crenate; petioles 

 slender, to 26 cm. long, usually much shorter; inflorescence an axillary simple 

 interrupted once- or twice-bifurcate (rarely tri- or quadrifurcate) spike, to 17 cm. 

 long, with 2 to 7 few-flowered verticils, the interverticillar distance to 6 cm., the 

 flowers sessile or subsessile; involucre of a few inconspicuous lanceolate bracts; 



1216 



