AMMIACEAE. 



273 



1. Hydrocotyle verticillata 

 Thunb. Whorled Marsh-pexxy- 

 WORT. (Fig. 293.) Inflores- 

 cence proliferous, ^\'-2' long; ver- 

 ticils 2-6-flowered; pedicels usu- 

 ally less than J" long; fruit about 

 1" long, l^"-2" broad, rounded 

 or truncate at each end; inter- 

 mediate ribs not corky-thickened, 

 the dorsal one acute. 



Frequent in fresh-water marshes, 

 and occasional near shaded borders 

 of salt water lagoons. Native. I']ast- 

 ern United States and West Indies. 

 Flowers from spring to fall. 



Hydrocotyle umbellata L., 

 which differs in having a single 

 umbel with slender pedicels 2"- 

 6" long, is recorded as Bermudian 

 by Rein, Reade, Lefroy, H. B. 

 Small and Hemsley, but careful 

 search of the marshes has failed 

 to reveal its existence in Bermuda; 

 its leaves are scarcely distinguish- 

 able from those of H. verticillata, 

 for which it may have been mis- 

 taken. 



2. CKNTELLA L. 

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

 rooting 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 flat- 

 tened laterally, rather prominently ribbed, the ribs mostly anastomosing; oil- 

 tubes none. [Latin, diminutive of 

 centrum, a prickle.] About 20 spe- 

 cies, most abundant in South Africa. 

 Type species: Centclla villosa L. 



1. Centella asiatica (L.) Urban. 

 Ovate-leaved Marsh-pexxywort. 

 (Fig. 294.) Stem l'-6' long. Petioles 

 2'-10' long, sometimes pubescent; 

 blades ovate, rather thick, rounded at 

 the apex, broadly cordate at the base, 

 not peltate, A'-2' long, repand-dentate; 

 pedicels much shorter than the leaves, 

 V-.2' long; umbellets capitate, 2-4- 

 flowered, subtended by 2 ovate bracts ; 

 flowers nearly sessile; fruit 2"-2i" 

 broad, about IV' high, prominently 

 ribbed and reticulated. [Hi/drocotyle 

 asiatica L. ; II. repanda Pers. ; Cen- 

 tella rcpanda J. K. Small:] 



Common in marshes and locally on 

 hillsides. Native. Southeastern United 

 States. West Indies. Old World tropics. 

 Flowers from spring to autumn. 



