5. Ipomoea pandurata (L.) G. Mey. (wild potato vine, man-of-the-earth, bigroot morning glory)

I. pandurata f. leviuscula Fernald

Pl. 367 e–g; Map 1600

Plants perennial, with a somewhat woody rootstock and a large, deep-set tuberous portion of the main root. Stems 40–500 cm long, glabrous or sparsely and inconspicuously hairy. Leaves long-petiolate. Leaf blades 2–12 cm long, unlobed, broadly ovate or sometimes pear-shaped in outline, tapered to a sharply pointed tip, shallowly to more commonly deeply cordate at the base, glabrous or the undersurface sparsely to moderately short-hairy, some of the hairs sometimes glandular, the margins entire. Flowers solitary or more commonly in loose clusters of 2–7(–13), the stalks glabrous. Sepals not similar in size and shape, the outer sepals noticeably shorter and slightly narrower than the inner ones, 13–20 mm long, oblong-elliptic to less commonly oblong-ovate, rounded or very bluntly pointed at the tip, occasionally tapered abruptly to a short, sharp point or shallowly notched, glabrous or less commonly minutely hairy toward the margins. Corollas 5–8 cm long, funnelform to slightly bell-shaped, the tube widened gradually toward the tip, white with a reddish purple center. Stamens not exserted. Ovary 2- or 4-locular, the stigma 2-lobed. Fruits ovoid, the main body 10–16 mm long, the persistent style 0.5–35.0 mm long and frequently becoming irregularly curled, glabrous. Seeds 7–9 mm long, the surface densely pubescent with minute, matted hairs, the angles with a crest of dense, long hairs. 2n=30. May–September.

Scattered to common nearly throughout the state (eastern U.S. west to Nebraska and Texas; Canada). Banks of streams and rivers, margins of ponds and lakes, and less commonly glades; also crop fields, fallow fields, old fields, ditches, railroads, roadsides, and open, disturbed areas.

The large, vertical, fleshy, tuberous root of this species, which can reach lengths of 0.6 m or more and can weigh more than 10 kg (Steyermark, 1963), is deep-set and difficult to excavate, but it is edible. Native Americans cooked and ate it as a starchy vegetable. However, the rootstock also has been said to have mild purgative properties.