2. Styrax L. (styrax, storax)
Plants shrubs
(small trees elsewhere). Bark gray, roughened. Twigs green to gray or reddish
brown, with lighter lenticels, shiny, pubescent with small stellate hairs when
very young, becoming glabrous with age, the winter buds ovoid to ellipsoid,
lacking scales, the pith solid. Petioles 3–10 mm long. Leaf blades narrowly to
broadly ovate or obovate, rarely oblanceolate, rounded to broadly angled at the
base, bluntly and broadly pointed to noticeably but abruptly tapered at the
tip, the margins minutely toothed to entire or nearly so, the upper surface
pale to dark green, glabrous or nearly so at maturity (sometimes minutely
stellate-hairy along the main veins when young), the undersurface pale green or
sometimes appearing grayish green to somewhat silvery, glabrous or sparsely and
minutely stellate-hairy at maturity. Inflorescences terminal and/or axillary,
clusters or short racemes of 2–20 flowers, sometimes of solitary flowers.
Flowers perigynous, the calyces fused to the ovary for about half of their
length, the stalk not jointed at the calyx base. Corollas deeply 5-lobed,
bell-shaped to broadly bell-shaped or more or less saucer-shaped, the lobes
often curled outward at full flowering. Stamens 10. Fruits drupelike, 5–11 mm
long, gray to grayish green, subglobose to somewhat obovoid, not or only
minutely beaked at the tip, not flattened, lacking wings, the surface densely
pubescent with a covering of minute stellate hairs, the middle layer waxy or
mealy, solid, indehiscent. Seeds with a relatively thick, hard coat, subglobose
to ovoid or ellipsoid, rounded or blunt at each end. About 130 species, North
America to South America, Caribbean Islands, Asia south to Indonesia.
Some species of Styrax
are cultivated as ornamentals. A resin collected from the injured trunks of
some of the Old World species is known as benzoin and gum benjamin. It has been
used in incense, perfumes, and flavored cigarettes. It also was used medicinally
in mixtures as a disinfectant and for the treatment of bronchitis and asthma.
It should be
noted that there has been considerable controversy over the gender of the
generic name Styrax (Wood and Channell, 1960; Howard, 1974). Current
practice favors neuter terminations (with epithets mostly ending in -us),
as Linnaeus (1753) intended in his original description of the genus.