1. Teucrium canadense L. (wood sage, American germander)
Pl. 444 a, b;
Map 2004
Plants perennial
herbs, with rhizomes, sometimes also producing tubers, often colonial. Stems
35–120 cm long, bluntly to strongly 4-angled, erect or strongly ascending,
unbranched or few-branched, moderately to densely pubescent with short,
downward-angled hairs and sometimes also with longer, spreading hairs. Leaves
opposite, sessile or short-petiolate, the petiole narrowly unwinged. Leaf
blades 3–12(–16) cm long, 1–5 cm wide, lanceolate to ovate or oblong-lanceolate,
angled at the base, angled or short-tapered to a sharply pointed tip, the
margins finely to coarsely toothed, the upper surface glabrous or sparsely to
moderately pubescent with short, loosely appressed hairs, the undersurface
sparsely to densely pubescent with short, curved, loosely appressed hairs or
relatively long, straight to woolly hairs, these tending to obscure the
inconspicuous sessile glands. Inflorescences terminal, dense spikelike racemes,
the flowers 2–6 per node and mostly overlapping those of adjacent nodes, the
stalks 1–4 mm long. Bracts progressively shorter from the inflorescence base to
tip, 4–25 mm long, leaflike, lanceolate to narrowly lanceolate or occasionally
linear, usually longer than the calyces. Bractlets absent. Calyces 5–9 mm long
at flowering, zygomorphic, lacking a lateral projection, more or less symmetric
at the base, bell-shaped, the tube finely 10-nerved, with scattered longer,
nonglandular hairs and sometimes also moderate, shorter, gland-tipped hairs in the
mouth, the outer surface usually densely hairy, 2-lipped, the lobes shorter
than the tube, the upper lip with 3 ovate to triangular lobes, straight or
slightly arched upward, the lower lip with 2 narrowly triangular lobes,
slightly arched upward, the lobes not spinescent, not becoming enlarged at
fruiting, but becoming somewhat leathery. Corollas 10–18 mm long, strongly
zygomorphic, corollas pinkish purple to pale lavender or rarely white, usually
with darker purple spots or mottling on the lower lip, the surfaces usually
moderately pubescent with short, gland-tipped hairs, sometimes also
gland-dotted, the tube funnelform, divided to below the midpoint, the upper lip
appearing absent, the lower lip prominent, 5-lobed, the 2 pairs of smaller
lateral lobes ascending to arched upward, the longer central lobe obovate to
somewhat rhombic, abruptly bent downward. Stamens 4, strongly exserted, the
filaments somewhat arched downward, the anthers small, the connective not
visible, the pollen sacs 2, parallel (back-to-back and dehiscing along opposite
sides, reddish brown to orangish brown. Ovary shallowly lobed, the style
appearing terminal or somewhat lateral from a shallow apical notch. Style
strongly exserted, with 2 slender branches at the tip. Fruits dry schizocarps,
consisting of usually 4 nutlets, these 1.5–2.5 mm long, broadly ovoid, the
surface light brown to reddish brown, glabrous, with a network of shallow
ridges or wrinkles. 2n=32. June–September.
Scattered to
common throughout the state (nearly throughout the U.S.; Canada, Mexico,
Caribbean Islands). Bottomland forests, bottomland prairies, upland prairies,
loess hill prairies, banks of streams and rivers, margins of sinkhole ponds,
fens, and marshes; also pastures, old fields, margins of crop fields, fencerows,
levees, railroads, and roadsides.
Teucrium
canadense is sometimes
cultivated as an ornamental, although it can spread aggressively in some garden
situations. According to Steyermark (1963), plants were once used medicinally
as a stimulant. The species is among several members of the Lamiaceae that have
been investigated as sources of natural rubbers (Buchanan et al., 1978).
McClintock and
Epling (1946), in their taxonomic revision of New World Teucrium,
recognized three varieties of T. canadense based primarily upon
differences in pubescence patterns, two of which occur in Missouri. Shinners
(1963) combined two of these three varieties, but named a third, var. nashii
(Kearney) Shinners, for plants of the southeastern United States similar to
var. canadense, but with the leaves silvery-hairy on the undersurface.