ï~~2004
THE MICHIGAN BOTANIST
21
TETRADIUM DANIELLIIH (KOREAN EVODIA; RUTACEAE)
AS AN ESCAPE IN NORTH AMERICA
Michael A. Vincent
W.S. Turrell Herbarium, Department of Botany,
Miami University, Oxford, OH 45056 USA,
513. 529. 2755,
[email protected]
Tetradium daniellii (Benn.) T. G. Hartley (Korean evodia, Rutaceae) is native to
Tibet and the Yunnan Province, China, northeast through China to North and
South Korea (Hartley 1981). The species first came to the attention of western
botanists in the mid-1800's, and was first described as a species of the genus Zanthoxylum by Bennett (in W.F. Daniell 1862). It was introduced into North America
about 1905 (Rehder 1947). In the horticultural trade, the tree has been known as
Evodia daniellii (Benn.) Hemsl. (Dirr 1997; Nelson 1997), though that generic
name is apparently most correctly spelled "Euodia", since Evodia is considered an
orthographic variant of the original spelling Euodia (Bean 1978; Mabberley 1997).
The genus Tetradium, containing 9 species (Flanagan 1988), is probably most
closely related to Phellodendron Rupr. and Zanthoxylum L. (Hartley 1981).
The genus Tetradium (as Evodia), especially fruit of T ruticarpum (A.Juss.)
T.G. Hartley (Evodiae Fructus), has been used medicinally in China to treat gastric and intestinal ailments for about 2000 years (Anonymous 2002a). It has also
been used to treat headaches, to decrease blood clotting, and to reduce arthritis
pain (Anonymous 2002b), and as a stimulant and antihelmintic (Mabberley
1997). Several bioactive alkaloids have recently been characterized from E. ruticarpa, and these may have use in treatment of obesity or ulcers (Ko et al. 2002).
Fruits of other species have been used in chutney (Mabberley 1997) and other
condiments (Daniell 1862). Several species are grown as ornamental trees (Rehder 1947).
Korean evodia (bebe tree, bee-bee tree, bee tree; Fig. 1) is a moderate-sized
tree or large shrub, reaching 8-12(-20) m tall, with a similar spread of the
crown. Its bark is smooth and gray to black. The young branches are pubescent,
becoming glabrous as the growing season progresses; winter buds are naked.
Leaves are 22-40 cm long, opposite to subopposite, odd-pinnately compound,
with 5-11 leaflets; leaves are deciduous, dropping when green, or turning yellowish in autumn. The leaflets are 5-13 cm long, ovate to oblong, acumimate at
the apex and acute to rounded at the base, short-petiolulate, with crenate margins; the upper leaf surface is glabrous, while the lower is somewhat pubescent,
at least when young; there are prominent to inconspicuous oil dots on the lower
surface. The small white to cream-colored unisexual flowers appear in June to
August, and are borne on the current years' growth on 10-17 cm broad, somewhat flattened terminal corymbs. Flowers are usually 5-merous, though occasionally 4-merous; sepals are slightly pubescent, 0.5-1.5 mm long; petals are
white to cream colored, glabrous adaxially and somewhat pubescent abaxially,
