1. Tetradium daniellii (Benn.) T.G. Hartley (Korean evodia)

Euodia daniellii (Benn.) Hemsl. (often spelled Evodia)

Map 2565

Plants small trees, dioecious, 5–12 m tall. Stems with ascending branches, the bark relatively smooth, gray to dark gray with scattered, lighter gray and brownish blotches, becoming somewhat roughened on old trunks, unarmed, the twigs olive brown, densely short-hairy when young, becoming gray and glabrous with age. Winter buds, naked, partially sunken into the petiole base (but mostly exposed). Leaves opposite or occasionally a few subopposite, mostly short-petiolate, the petiole not jointed at the tip, unwinged. Leaf blades 15–38 cm long, pinnately compound with 5–11 leaflets, these 5–13 cm long (progressively longer from the basal pair), oblong-elliptic to elliptic or ovate, the lateral pairs usually somewhat oblique, rounded to short-tapered to a sessile or short-stalked base, short-tapered or tapered to a sharply pointed tip, the margins minutely scalloped, the upper surface green, glabrous or sparsely and inconspicuously hairy toward the base of the midvein, the undersurface pale green to light green, sparsely and inconspicuously hairy when young, generally appearing glabrous at maturity. Inflorescences terminal, much-branched, dome-shaped panicles, the individual flowers short-stalked. Flowers imperfect. Sepals (4)5, 0.5–1.5 mm long, broadly triangular, fused toward the base, the margins hairy, usually persistent at fruiting. Petals (4)5, 3–5 mm long, narrowly oblong-ovate to narrowly oblong-elliptic, overlapping in bud, white to cream-colored, mostly with thin, minutely uneven margins, sparsely hairy on the upper surface. Stamens in staminate flowers (4)5 (reduced to short, strap-shaped staminodes in pistillate flowers), alternating with the petals, the filaments free, slender, sparsely hairy toward the base, attached to a more or less cup-shaped to short-cylindric nectar disc around the ovary base. Ovary (4)5-locular, deeply (4)5-lobed from the tip (reduced to a more or less lobed rudiment in staminate flowers), sparsely hairy toward the tip, each locule with 2 ovules, the short, stout style attached at the concave ovary tip, the stigma more or less disc-shaped. Fruits (4)5 follicles per flower, these fused at the base or nearly separate, 6–11 mm long, asymmetrically obovoid to ellipsoid, tapered or narrowed to the fused basal portion, abruptly tapered to a minute, oblique beak at the tip, the outer surface leathery, smooth to finely pitted, red to dark red or nearly black, sometimes brownish yellow with a pinkish tinge, glabrous or nearly so. Seeds 1 or 2 per fruit, 2.5–4.0 mm long, usually only 1 of the pair fertile, oblong-ellipsoid, the outer surface smooth, black, shiny. 2n=78. June–August.

Introduced, uncommon, known thus far only from Greene County (native of Asia; introduced uncommonly thus far in Missouri, Ohio, and Pennsylvania). Disturbed mesic upland forests.

This species was first reported for Missouri by Bowe and Redfearn (2002, as Evodia). Vincent (2004b) discussed its recent spread in the United States. Likely, this species will become more widely naturalized in the future. Vincent (2004b) also noted that in its native range, the species has a long history of medicinal use for intestinal ailments, arthritis, and other problems. He further noted that the species is highly prized as a bee plant, especially as the trees flower heavily at a time of year when relatively few other resources are available for honeybees.

Another Asian taxon in the Rutaceae that likely will become a member of the Missouri flora in the near future is Phellodendron amurense Rupr. (Amur corkbark tree). In 2008, Glenn Beffa of the staff of the Shaw Nature Reserve (Franklin County) reported a large individual persisting from an old planting at a presently undeveloped site at the property. He noted further that seedlings were present under and around the mature tree. Shortly thereafter, Steve Buback of Forest Park (St. Louis City) reported a similar situation at that property. There has been an effort to eradicate individuals at Shaw Nature Reserve, which is managed as a natural landscape, and as of this writing Forest Park is considering a similar course of action. Amur corkbark tree is cultivated as a shade tree in temperate North America and has escaped in scattered eastern and Midwestern states, as well as in eastern Canada. In some eastern states, it is considered an invasive exotic. Like Tetradium, P. amurense is a small to medium-sized, dioecious tree with large, opposite, pinnately compound leaves and large panicles of numerous small flowers terminal on the branches. It differs from Tetradium in its relatively thick, corky bark, fruits that are fleshy, drupelike berries, leaves with 7–13 leaflets, and in having axillary buds that are concealed in the hollow, expanded bases of the petioles.