Kral’s water-plantain typically occurs on frequently exposed shoals or rooted among loose boulders in quiet pools up to 3.2 feet (1 meter) in depth. Plants are locally distributed where suitable habitat exists, and grow in pure stands or in association with various submergents, meaning below-water plants, and emergents, meaning above-water plants. The immediate banks are often dominated by thickets of shrubs and adjacent sphagnous seeps which are commonly contain sedges. Streams with Kral’s water-plantain occurrences are typically narrow and bounded by steep slopes. 

Kral’s water-plantain occurs in a small number of locations in Alabama and Georgia, with relatively small numbers of plants in each population. Three of the four extant populations occur in streams within federally managed lands (Little River Canyon National Preserve and Bankhead National Forest). Although the Bankhead National Forest and the National Park Service provide for standards and protective measures for the Kral’s water-plantain, siltation from silviculture, land use practices that lead to changes in hydrology and/or degradation of water quality, and recreational use of the river corridor act as threats or stressors to the species. Overall, siltation, eutrophication due to sewage input, and impoundments currently threaten Kral’s water-plantain continued viability. Activities that increase stream turbidity or siltation from erosion pose a threat to this species by reducing the amount of light reaching this submersed plant and burying it under silt. Eutrophication may lead to algal growth on the plant and result in degraded water quality. Unstable dams may break and release high volumes of water and sediment, uprooting plants and burying remaining plants. Kral's water-plantain could become vulnerable to extinction due to its limited range.

Kral’s water-plantain is a member of the water-plantain family (Alismataceae) in the graminea complex of Sagittaria. Distinguishing characteristics include a stout, elongated rhizome, hairy filaments, linear leaves and spreading, or reflexed, sepals. Kral’s water plantain is a submersed to emersed aquatic, perennial herb. It can float above or below the water. The leaf shape depends on the velocity and depth of the water it inhabits. In swift shallows, the leaves are linear, rigid, and sickle shaped, 2 to 3 inches (5 to 8 centimeters) long and 0.08 to 0.20 inches (2 to 5 millimeters) wide. In quiet, deeper waters, the leaves are more quill-like, being longer 4 to 12 inches (10 to 30 centimeters), linear in shape and tapering. The plant produces separate male and female flowers on a 4 to 20 inches (10 to 50 centimeters) stalk. The petals are inconspicuous in the female flowers. Male flowers are white and 0.4 to 0.6 inches (1.0 to 1.5 centimeters). The fruit consists of a cluster of small, dry, single seeded fruits approximately 0.08 inches (2 millimeters) in length. Although infrequent, flowering occurs from May into July, and intermittently into fall, as documented by R. Kral in 1982.