1. Styrax americanus Lam. (snowbell, American snowbell, mock
orange)
S. americanus var. pulverulentus (Michx.)
Rehder
Pl. 568 g, h;
Map 2653
Plants shrubs to
4 m tall. Petioles 3–5 mm long. Leaf blades 1.5–10.0 cm long, mostly elliptic
to oblong or ovate, rarely broadly elliptic to obovate, the margins entire or
with small teeth scattered on each side, the upper surface glabrous, dark green
to green, the undersurface glabrous or sparsely and minutely stellate-hairy at
maturity (more densely hairy elsewhere), pale green. Inflorescences axillary,
sometimes appearing terminal at the ends of short branches, clusters or less commonly
short racemes of 2–5 flowers, sometimes of solitary flowers. Calyces (including
the hypanthium) 2.5–4.0 mm long, the tube (hypanthium) obconic at flowering,
sparsely stellate-hairy to nearly glabrous, shallowly 5-lobed, the lobes
0.5–1.0 mm long, triangular, sharply pointed. Corollas 10–16 mm long. Fruits
(5–)8–10 mm long, 6–8 mm wide, subglobose to somewhat obovoid. 2n=16.
April–May.
Uncommon in the
Mississippi Lowlands Division (southeastern U.S. west to Missouri and Texas).
Swamps and bottomland forests; also levees, ditches, and wet roadsides.
Steyermark
(1963) noted that S. americanus is a very showy shrub when in flower and
has been underutilized in Missouri landscaping, perhaps in part because the
species requires a moist environment to reach its potential.
Gonsoulin (1974)
separated plants with more persistently hairy foliage and slightly broader
leaves as var. pulverulentus and cited a specimen collected by Julian
Steyermark in Butler County as this variety. However, Steyermark (1963) himself
had studied the situation earlier and concluded that the hairier variety did
not occur in Missouri. Part of the disagreement stems from the fact that the
differences between the varieties are not sufficient to permit formal taxonomic
recognition and numerous intermediates with varying degrees of leaf pubescence
exist.