A bog herb with slender acrid rootstocks, broadly ovate or nearly orbicular cordate leaves, and a large white persistent spathe. Spathe ovate-lanceolate or elliptic, acuminate, open. Spadix cylindric, much shorter than the spathe, densely covered with flowers. Flowers perfect or the very uppermost staminate; perianth none. Stamens about 6; filaments linear, longer than the anthers; anther-sacs divaricate, opening by slits. Ovary ovoid, i-celled; style very short; stigma small, flat, circular. Ovules 6-9, anatropous. Berries obconic, depressed. Seeds hard, smooth, oblong, striate toward the micropyle and pitted at the other end. Endosperm copious. [An ancient name, taken from Pliny.]

A monotypic genus of the cooler portions of the north temperate zone.

1. Calla Palustris L. Water Arum. Wild Calla

Fig. 1116

Calla palustris L. Sp. PI. 968. 1753.

Petioles 4'-8' long, spreading or ascending. Blades thick, entire, 1 1/2'-4' wide, cuspidate or abruptly acute at the apex, deeply cordate at the base; scapes as long as the petioles, sheathed at the base; rootstocks covered with sheathing scales and with fibrous roots at the nodes; spathe 1'-2 1/2' long and about 1' wide, with an abruptly acuminate involute apex; spadix about 1' long; berries red, distinct, few-seeded, forming a large head when mature.

In bogs, Nova Scotia to Hudson Bay, Minnesota, New Jersey, Pennsylvania, Wisconsin and Iowa. Reported from Virginia. Also in Europe and Asia. Female or water-dragon. Water-lily. Swamp-robin. May-June. Fruit ripe July-Aug.