1. Rhexia L. (meadow beauty)
(Kral and Bostick, 1969)
Plants perennial
herbs, sometimes slightly woody at the base. Pubescence of relatively long,
spreading, bristly hairs, these all or mostly with dark glandular tips. Stems
solitary or few, erect or ascending, often 4-angled or -winged above the basal
portion. Leaves opposite, sessile or short-petiolate. Stipules absent. Leaf
blades simple, with 3(5) palmate main veins more or less parallel to the
margins, narrowed or tapered to a sharply pointed tip, narrowed or rounded at
the base, the margins sharply and finely toothed, the teeth often hair-tipped.
Inflorescences usually appearing as small panicles, with small loose clusters
subtended by small leaflike bracts at the nodes (these often shed by fruiting).
Flowers with the perianth actinomorphic and the stamens and to some extent the
pistil zygomorphic, perfect, epigynous (but the hypanthium often becoming
somewhat free from the mature fruits and the ovary then appearing superior).
Hypanthium tubular at flowering, persistent and becoming urn-shaped as the fruit
matures, extended past the ovary as a short necklike tube. Calyces of 4 free
lobelike sepals at the hypanthium tip, these 2–4 mm long, triangular, sharply
pointed at the tip, persistent at fruiting. Corollas of 4 free petals, these
spreading, somewhat asymmetrically oblong to broadly obovate, rounded or with
an abrupt small narrow point at the tip, pink to rose-purple (rare white forms
not yet found in Missouri). Stamens 8, strongly exserted at flowering, subequal
in size, the filaments fused to the inner apical portion of the hypanthium,
S-shaped and curved downward, the anthers 5–8 mm long, attached just above
their bases, strongly curved outward, yellow, dehiscing by terminal pores.
Pistil of 4 fused carpels, inferior (but often appearing superior at fruiting).
Ovary 4-locular, the placentation axile. Style 1 per flower, somewhat curved
downward, about as long as the stamens (including the anthers), the stigma
depressed-capitate to somewhat disc-shaped, entire or nearly so. Ovules
numerous. Fruits capsules, dehiscing irregularly and longitudinally between the
sutures. Seeds numerous, 0.4–0.7 mm long, flattened and spiral-shaped
(snail-shell-shaped), the surface brown, with several concentric, spiralled
ridges along the sides and especially along the keel, these varying from smooth
to warty or tubercled. Eleven species, U.S., Canada, Caribbean Islands, most
diverse along the Atlantic and Gulf Coastal Plains.
Meadow beauties
often occur in dense colonies and are very attractive when flowering. They can
be cultivated successfully in the garden if planted in moist sandy or otherwise
acidic soils. The stems of Rhexia species often persist through the
winter, leafless but with noticeable, persistent, urn-shaped hypanthia. These
are sometimes used in dried flower arrangements.