1. Cunila origanoides (L.) Britton
(dittany)
Pl. 433 c, d;
Map 1944
Plants perennial
herbs, with an often somewhat woody rootstock and short, slender rhizomes.
Stems 20–40(–60) cm long, erect or strongly ascending, bluntly (toward the stem
base) to relatively sharply 4-angled, several- to numerous-branched, glabrous
or sparsely pubescent with short, spreading and/or, crinkly hairs, sometimes
mostly along the angles or along 2 opposing, slightly concave sides. Leaves
opposite, sessile or nearly so. Leaf blades 1.5–4.0 cm long, 0.7–2.0 cm wide,
narrowly to broadly ovate, rounded or occasionally shallowly cordate at the
base, angled or tapered to a sharply pointed tip, the margins finely toothed or
rarely entire, the surfaces glabrous or sparsely to moderately pubescent along
the midvein or main veins with stiff, spreading, multicellular hairs (also
sometimes with a few such hairs in the axils of the marginal teeth), also with relatively
conspicuous sessile glands. Inflorescences terminal and axillary, dense
clusters of 6 to numerous flowers, these short-stalked to nearly sessile
(0.5–2.0 mm). Bracts inconspicuous (to 1 mm long), linear to narrowly
lanceolate, shorter than the flowers. Calyces 1.5–3.0 mm long at flowering,
actinomorphic, lacking a lateral projection, symmetric at the base, funnelform
to narrowly bell-shaped, the tube strongly 10-nerved (-ribbed), with a fringe
of short, bristly hairs in the mouth, the lobes variously shorter than the
tube, narrowly triangular to triangular, not spinescent, glandular on the outer
surface, not becoming enlarged or papery at fruiting. Corollas 6–8 mm long,
weakly zygomorphic, pinkish purple to lavender or sometimes white, not spotted,
the surfaces moderately to densely and minutely hairy, also glandular, the tube
funnelform, slightly 2-lipped, the lips up to half as long as the tube, the
upper lip notched at the broadly rounded tip, straight or slightly arched, the
lower lip 3-lobed, arched to spreading. Stamens 2, strongly exserted, the
anthers small, the connective short, the pollen sacs 2, parallel or nearly so,
yellowish purple to nearly white. Ovary deeply lobed, the style appearing
nearly basal from a deep apical notch. Style not or only slightly exserted,
with 2 slender branches at the tip. Fruits dry schizocarps, separating into 2–4
nutlets (rarely the nutlet solitary), this 0.8–1.0 mm long, ellipsoid to ovoid,
the surface yellowish brown to brown, glabrous, smooth or very finely pebbled.
July–November.
Scattered
throughout the Ozark and Ozark Border Divisions, also in portions of the
Mississippi Lowlands and the southeasternmost part of the Glaciated Plains
(eastern U.S. west to Kansas and Texas). Mesic to dry upland forests, savannas,
upland prairies, sand prairies, ledges and tops of bluffs, and banks of streams
and rivers; also old fields and roadsides; often on acidic substrates.
The crushed
foliage of C. origanoides has a pleasant minty odor and the dried
foliage has been used in teas, sachets, and potpourri. Acording to Moerman
(1998), Native Americans used the plant as an antiseptic, for pain relief, to
lower fevers, and as a tonic. The essential oils sometimes are extracted for
medicinal use or for a flavorant in cooking. However, a number of Old World
species are extracted commercially more commonly to produce the so-called oil
of dittany, including the oregano relative, Origanum dictamnus L., and
some members of the genus Dictamnus L. (Rutaceae).
Steyermark
(1963) stated that C. origanoides is a desirable ornamental in
wildflower gardens and rock gardens. He also noted that the species is noted as
a frequent producer of spectacular frost flowers at the end of the
growing season. These are formed when sudden overnight freezing temperatures
cause the stems to burst, with the resultant release of quantities of sap that
are pumped up from the still metabolically active roots. The exuded liquid
freezes into intricate layered petal-like or ribbony shapes of ice sometimes
more than 5 cm long. This phenomenon was described in fanciful detail by L. F.
Ward (1893), who called the plant by the superfluous name Cunila mariana
L. and referred to the exudate as frost freaks.