1. Hibiscus laevis All. (rose mallow, halberd-leaved rose
mallow)
H. militaris Cav.
Pl. 452 a–d; Map
2051
Plants perennial
herbs, sometimes slightly woody at the base. Stems 80–200 cm long, erect or
ascending, glabrous, often somewhat glaucous. Leaf blades 4–20 cm long, ovate
or less commonly elliptic-lanceolate in outline, shallowly to deeply 3-lobed
(hastate) at the base, less commonly unlobed, the margins relatively finely and
sharply toothed, the upper surface glabrous, the undersurface glabrous or
sparsely pubescent with stellate hairs along main veins. Stipules shed during
leaf development. Bractlets subtending the calyx 8–12(–15), 12–25 mm long,
glabrous or pubescent with unbranched or fasciculate hairs along the margins.
Calyces 25–35 mm long at flowering, becoming slightly enlarged to 40 mm and
slightly inflated at fruiting, glabrous or sparsely and finely pubescent with
stellate hairs along the veins. Petals 6–8 cm long, white or more commonly
pink, usually with dark reddish purple bases. Fruits 2.2–3.2 cm long, ovoid to
ovoid-cylindric, glabrous except for dense simple and fasciculate hairs along
the inner side of the margins of the valves (visible after dehiscence). Seeds
12–18 per locule, 3.2–3.8 mm long, broadly kidney-shaped to nearly globose, the
surface densely covered with short stiff orangish brown hairs, dark brown. 2n=38.
July–October.
Scattered,
mostly outside the Ozark Division (eastern U.S. west to Nebraska and Texas).
Openings of bottomland forests, swamps, banks of streams and rivers, and
margins of ponds, lakes, sinkhole ponds, and sloughs, sometimes in shallow
water; also ditches and wet roadsides.
Hibiscus
laevis frequently forms
large colonies. Its seeds are eaten by wildlife, particularly birds. Although
this species and H. lasiocarpos are sometimes found growing together,
especially in disturbed habitats like roadside ditches, hybridization between
them is rare and the hybrids (of intermediate general morphology) produce
shrunken abortive seeds. O. J. Blanchard (1976), who examined more than 3,000
herbarium specimens from throughout the provenance of these species and
conducted extensive field work, located only 8 specimens rangewide representing
putative hybrid plants. From Missouri, he located only a single historical
collection from waste ground along a railroad in Jasper County.