tuberous Indian plantain

not listed

S2 - Imperiled

Threatened

FAC - Facultative

FAC - Facultative

FAC - Facultative

Tuberous Indian plantain is an erect, perennial forb that rises on a rosette of basal leaves and a single stem from a horizontal underground stem (rhizome) and fleshy roots. In Minnesota it is usually 20″ to 40″ tall, though in other parts of its range it can reach 70″ in height. It occurs from Ontario to Texas and Georgia. It is most common in the Midwest from Iowa and Illinois to Texas and Louisiana. It is rare in Minnesota, where it is listed as a threatened species.

The stem is erect, stout, angled, grooved, hairless, and unbranched below the inflorescence. It is green and has a fine, reddish-purple, longitudinal line on each angle, at least near the base of the plant. It is not covered with a whitish waxy bloom (glaucous).

Basal leaves are thick, firm, leathery, 3″ to 8″ long, and 1″ to 3″ wide. They are on stout, greenish-white to reddish-green, up to 4″ long leaf stalks (petioles). The leaf blades are elliptic to egg-shaped, unlobed, rounded or bluntly pointed at the tip, and tapered at the base. The margins are greenish-white to reddish-green, usually untoothed, sometimes wavy, sometimes coarsely toothed. The upper and lower surfaces are hairless but not glaucous. There are 7 to 10 conspicuous, more or less parallel veins diverging from the base and converging at the tip.

Stem leaves are alternate and get progressively smaller and shorter stalked as they ascend the stem. Lower stem leaves are similar in size and appearance to basal leaves. Upper stem leaves are short stalked, egg-shaped to narrowly inversely egg-shaped, and tapered at the base. They are usually untoothed, sometimes coarsely toothed. Uppermost leaves are often stalkless.

The inflorescence is a flat-topped, branched, loose, 3″ to 8″ in diameter cluster (cyme) at the end of the stem. The flowers in the center on the cyme open first, the outermost flowers open last. The branches of the cyme are greenish-white and hairless.

Each flower head is 5 ⁄16″ to ⅜″ long and ⅛″ to 3 ⁄16″ wide. The whorl of bracts at the base of the flower head (involucre) has sharp, wing-like keels. The bracts are green with white keels and white tips. Each flower head has five disk florets. The corollas are 5 ⁄16″ to 7 ⁄16″ long, and white or cream-colored. They have 5 lobes that strongly bend backward. They extend only slightly beyond the involucre. The style is branched and has a stigmatic band along the inner surface of each branch.

The fruit is a dry, ⅛″ to 3 ⁄16″ long capsule (achene) with a tuft of ¼″ to ⅜″ long hairs attached at the end. The achene is dark brown and narrowly oval, and has 5 to 12 longitudinal ribs.

20″ to 40″

Greenish-white to white or cream-colored

Usually wet to moderate moisture,rarely dry. Wet prairies, pastures, and bogs. Full to partial sun.

June through August

Sources

2, 3, 4, 5, 7, 28, 29, 30.

Native

Rare in Minnesota

Plant

Inflorescence

Flowers

Basal Leaves

Stem Leaves

Stem