Perennial herbs, prostrate and commonly rooting at the joints, with palmately lobed or veined, often peltate leaves, the bases of the petioles with 2 scale-like stipules, and small white flowers in peduncled or sessile simple or proliferous umbels or heads. Bracts of the involucre few and small, or none. Calyx-teeth minute. Petals entire. Disk flat. Fruit laterally compressed, orbicular or broader than high. Carpels with 5 primary ribs, the lateral ones usually curved; no large oil-tubes, but an oil-bearing layer of tissue beneath the epidermis. [Greek, water-cup.]

About 75 species of wide distribution. Besides the following another occurs in the Southwest and on the Pacific Coast. Type species: Hydrocotyle vulgaris L. The species are known as Marsh-, or Water-pennywort, or Water-cup.

Leaves nearly orbicular, peltate.

Umbels simple, rarely slightly proliferous; pedicels slender.

1.

H. umbellata.

Umbels, at least some of them, proliferous; pedicels, or some of them, short

Fruit notched at each end.

2.

H. Canbyi.

Fruit not notched at either end.

3.

H. verticillata.

Leaves nearly orbicular, cordate, or reniform, not peltate.

Flowers umbellate.

Leaves 5-9-lobed; umbels nearly sessile.

4.

H. americana.

Leaves 3-7-cleft; umbels long-peduncled.

5.

H. ranunculoides.

Umbels capitate, the beads peduncled.

6.

H. rotundifolia..

1. Hydrocotyle Umbellàta L. Umbellate Or Many-Flowered Marsh-Pennywort

Fig. 3154

Hydrocotyle umbellata L. Sp. Pl. 234. 1753.

Glabrous, stem creeping, several inches long, the subterranean branches tuberiferous. Petioles slender, erect, or ascending, 1'-6' long; leaves peltate, orbicular, or broader than long, sometimes cordate at the base, 1/2'-2' wide, crenately 7-11-lobed, the lobes broad, not deep, mostly crenulate; peduncles elongated; umbels simple or rarely with a proliferous extension; pedicels slender, 2"-6" long; mature fruit notched at both ends, 1"-1 1/2" broad, not quite as long; intermediate ribs corky-thickened; dorsal rib obtuse.

In swamps and low grounds, eastern Massachusetts to Florida and the West Indies, Minnesota, Texas and Mexico. Also in South America and South Africa. June-Sept. Water-navelwort. Water-grass.

1 Hydrocotyle Umbell Ta L Umbellate Or Many Flower 14961 Hydrocotyle Umbell Ta L Umbellate Or Many Flower 1497