AMMIACEAE 859 



i 



leaves or longer : umbels proliferous, and forming an interrupted raceme, the whorls few- 

 flowered : pedicels usually 1-3 mm. long : fruit depressed, 2 mm. high, 3-4 mm. broad, 

 rounded or truncate at the base and apex, the ribs prominent, the dorsal acute, none of 

 them corky, [i?. inteirupta Muhl.] 



In low grounds or swamps, Massachusetts to Arkansas, Florida and Texas. Spring to fall. 



6. Hydrocotyle australis Coult. & Rose. Similar to H. Canbyi in habit. Umbels 

 proliferous, the 3-6 whorls few-flowered : pedicels 2-4 mm. long : fruit 2 mm. long and 

 slightly broader, rounded at tlie base. 



In low grounds, Virginia to Florida and Texas. Spring to fall. 



7. Hydrocotyle cuneata Coult. & Kose. Resembling H. australis in habit. Umbels 

 proliferous, the few whorls few-flowered : pedicels very short : fruit 2 mm. long, 3-4 mm. 

 broad, tapering to the pedicels by a cuneate base. 



In damp places, Texas to California. Spring to fall. 



8. Hydrocotyle ranunculoides L. f. Rootstocks extensively creeping, or often 



floating : leaf-blades rather fleshy, not peltate, reniform or orbicular-reniform, 2-5 cm. 



broad, 3-7-lobed, cordate, tlie lobes crenate : peduncles 1-8 cm. long, shorter than the 



leaves : umbels capitate, 5-10-flowered : pedicels often 1-2 mm. long at maturity : fruit 



2-3 mm. broad, obscurely ribbed, oblong in cross-section. 



In ditches, swamps and shallow ponds, Pennsylvania to Florida and Texas. Also on the Pacifle 

 Coast from Oregon to Lower California. Spring to fall. 



9. Hydrocotyle Americana L. Rootstocks creeping, often producing elongated 

 tubers : leaf-blades thin, not peltate, reniform, 2-5 cm. broad, crenate and crenate-lobed, 

 cordate : peduncles very short : umbels axillary, few-flowered : nearly sessile : pedicels 

 commonly less than 1 mm. long : fruit 1-1.5 mm. broad, slightly ribbed, oval in cross-sec- 

 tion, the oil-bearing layer obsolete. 



In damp soil, Nova Scotia to Ontario and Minnesota, south to Pennsylvania and in the mountains 

 to North Carolina. Spring to fall. 



2. CENTELLA L. 



Perennial herbs, with creeping or horizontal rootstocks. Leaves clustered at the nodes, 

 with long erect petioles : blades entire or toothed, palmately nerved. Bracts of the invo- 

 lucre 2-4, small. Flowers in capitate long-peduncled umbels. Hypanthiura truncate. 

 Sepals obsolete. Petals white, obtuse, imbricated. Disk flat or concave. Fruit lenticular, 

 laterally flattened, suborbicvdar, cordate or reniform, smooth : carpels without large oil- 

 tubes, the prominent ribs anastomosing. Seeds lenticular. 



1. Centella repinda ( Pers. ) Small. Foliage glabrate or slightly pubescent. Root- 

 stocks elongated : leaves clustered ; petioles erect, 10-30 cm. long ; blades thickish, ovate, 

 2-6 cm. long, obtuse, repand, cordate or nearly truncate at the base : peduncles usually 

 several together, villous, 1-6 cm. long, mostly shorter than the petioles : umbels 2— 4 flow- 

 ered, chiefly capitate : fruit depressed, 4-5 mm. broad, prominently ribbed and reticulated. 

 l_Hydrocotyle repanda Pers.] 



In sand or moist pine lands, Maryland to Florida and Texas.— A form from eastern Florida, with 

 petioles about 2.5 era. long and larger fruit, is C. repanda Floriddna (Coult. & Rose) Small. [^Hydrocotyle 

 Asiatica var. Floridana Coult. & Rose.] 



3. BOWLESIA R. & P. 



Annual caulescent herbs, with stellate pubescence. Leaves opposite : blades merely 

 lobed. Flowers in simple, few-flowered umbels which terminate axillary peduncles. Sepals 

 5, prominent. Corolla white. Disk rather flat. Fruit turgid, smooth : carpels ribless, 

 becoming depressed on tlie back, nearly distinct : oil-tubes wanting or obsolete. Seed dor- 

 sally flattened, the face essentially flat. 



1. Bowlesia septentrionalis Coult. & Rose. Stems weak, 0.5-6 dm. long, dichoto- 

 mously branched : leaf-blades reniform to ovate-cordate, 1.5-3 cm. broad, thin, 3-5-lobed, 

 slender-petioled : umbels short-peduncled, 1-4-flowered : fruit about 2 mm. long, sessile or 

 nearly so. 



In rich or shaded ground, Texas to California. Spring. 



4. SANICULA L.i 



Biennial or jjerennial caulescent herbs. Leaves alternate : blades pinnatifid or pal- 

 mately 3-7-foliolate : leaflets toothed or incised. Flowers usually unisexual, in irregular 



1 Contributed by Mr. E. P. Bicknell. 



