Bog Arum

Calla palustris (KAL-lah pal-OOS-triss)

Family: Araceae Non-native Herbaceous (1-3 ft)

Wild Calla is a small, rhizomatous, aquatic perennial with heart-shaped leaves and bears showy flowers and fruits during the summer. Colonies are frequently found in shallow waters of bogs, rivers, lakes, ponds, or swamps of the temperate and subarctic regions. They are members of the Araceae or Arum family. Other common names include Water Arum, Wild Dragon, Bog Arum, and Swamp Lily. The plant is native to Alaska, Canada, the northern United States, northern Europe, and northern Asia. The genus name, Calla , is Greek in origin for Kallos and means "beauty." The species name, palustris , means "marsh-loving." Wild Calla prefers partial shade as well as acidic, humus-rich, and moist to wet soils. They may grow in shallow water. The plant is propagated by seeds or rhizome division. The plant grows about 6 to 12 inches tall. The leaves are medium to dark green, heart-shaped, waxy, smooth, and have pointed tips and curling leaf margins. The leaf petioles are 10 inches long and rise from the rhizomes. A single flower appears on a stout stem which is about 4-12 inches tall. Each flower has an oval white spathe that partially surrounds an upright cylinder-like spike or spadix. The spadix is yellowish-green in color and is covered with small petalless yellow flowers. Blooms appear from May to June. Clusters of tiny pear-shaped fruits develop on the spadix after flowering. The fruits ripen from green to bright red in late summer. The roots are long and fibrous. The foliage of this plant contains calcium oxalate that is toxic to animals and humans. The substance irritates the gastrointestinal tract. However, black bears may use the foliage as a food source in the early spring when food sources are limited. In temperate regions, the plant may be used in ponds, streams, Rain Gardens, and Water Gardens. The flowers of the spadix are short-lived, but the white spathe is retained for a longer time. The medium-dark green foliage and bright red berries are showy and add interest to wetlands. Insects, Diseases, and Other Plant Problems: There are no serious diseases or pest problems.

Source: NC State Extension Gardener Plant Toolbox ↗ NC State Extension Gardener Plant Toolbox, 67 attributes.