1. Nyssa aquatica L. (swamp tupelo, water tupelo, cotton gum, tupelo, tupelo gum)

N. uniflora Wangenh.

Map 1611, Pl. 369 m, n

Plants large trees to 35 m tall, the trunk usually tapered from a swollen and/or buttressed basal portion, the bark relatively thin, finely fissured, the ridges sometimes broken into small, scaly plates, dark brown or gray. Twigs reddish brown to brown, relatively stout. Leaves with petioles 3–6 cm long, these usually densely pubescent with spreading, sometimes tangled, mostly 2-branched hairs. Leaf blades 10–30 cm long, 5–12 cm wide, ovate, elliptic, or obovate, the margins entire or with 1 to few, coarse, broadly triangular, spreading teeth and usually also hairy, tapered, angled, or occasionally shallowly cordate at the base, tapered to a sharply pointed tip, the upper surface glabrous, not shiny, the undersurface glabrous or sparsely hairy along the main veins, pale green and glaucous. Staminate flowers in dense, headlike clusters 1.0–1.5 cm in diameter, the inflorescence stalk 1.0–1.5 cm long. Pistillate flower 1 per inflorescence, the inflorescence stalk 2–5 cm long. Petals 2–3 mm long, oblong, usually rounded at the tip. Fruits 2–3 cm long, oblong-ellipsoid, dull yellow to olive green, turning purplish black, with scattered minute, white spots, glaucous, bitter, the stone with 8–10 sharply angled longitudinal ridges. April–May.

Uncommon in the Mississippi Lowlands Division and adjacent southeastern portion of the Ozarks (southeastern U.S. west to Missouri and Texas). Swamps, bottomland forests, sloughs, banks of streams and rivers, and sinkhole ponds, often emergent aquatics.

Tupelo gum is common in the southeastern states in areas that are periodically flooded, in habitats where many other species cannot survive. In Missouri it was a dominant species in the swampy forests of the Mississippi Lowlands Division before the nearly complete clearing and draining of that portion of the state for agriculture. Its disjunct presence in a couple of upland sinkhole ponds in the Ozarks is remarkable.