28. Stachys L. (hedge nettle)
(Mulligan and Munro, 1989)
Plants perennial
herbs (annual elsewhere), often with rhizomes, sometimes also with tubers.
Stems erect or ascending, bluntly to sharply 4-angled, unbranched or branched,
glabrous or hairy, the hairs not felted or woolly. Leaves sessile or short- to
long-petiolate, the petiole unwinged. Leaf blades variously linear to narrowly
oblong or narrowly lanceolate to broadly ovate, angled to rounded or
occasionally shallowly cordate at the base, angled or tapered to a usually
sharply pointed tip, the margins with relatively closely spaced, fine, sharp
teeth, the surfaces glabrous, roughened, or sparsely to moderately short-hairy,
also with inconspicuous, sessile glands. Inflorescences terminal, spikes,
composed of distinct clusters, these widely or relatively densely spaced along
the axis, but noticeably discrete and with the flowers not overlapping those of
adjacent nodes, or less commonly dense, more or less continuous, the flowers in
small clusters of 4 or 6(8) per node (flowers 2 or 3[4] in the axil of each
bract), the clusters not headlike. Bracts similar to the foliage leaves but
much smaller. Bractlets absent or very short, linear, and inconspicuous.
Calyces actinomorphic or nearly so, lacking a lateral projection, more or less
symmetric at the base, narrowly bell-shaped, the tube 5- or 10-nerved, 5-lobed,
the lobes somewhat shorter than to about as long as the tube, similar in size
and shape, triangular to narrowly triangular, not spinescent, not becoming
enlarged or papery at fruiting. Corollas zygomorphic, white, light pink, or
pale purple, the lower lip usually with reddish purple to dark purple or
whitish (in darker corollas) spots or mottling, the outer surface sparsely to
moderately pubescent with short, gland-tipped hairs, especially on the lobes,
the tube funnelform, relatively deeply 2-lipped, the lobes slightly shorter
than the tube, the upper lip usually slightly shorter than the lower lip,
entire or shallowly notched, slightly concave to more or less hooded, the lower
lip spreading to arched, 3-lobed with a large central lobe and 2 small lateral
lobes. Stamens 4, not exserted, the lower pair with slightly longer filaments
than the upper pair, all ascending under the upper corolla lip, the anthers
small, the connective very short, the pollen sacs 2, spreading, usually dark
purple. Ovary deeply lobed, the style appearing nearly basal from a deep apical
notch. Style exserted, more or less equally 2-branched at the tip. Fruits dry
schizocarps, separating into usually 4 nutlets, these 1.5–2.5 mm long,
oblong-obovoid to broadly obovoid, rounded at the tip, somewhat 3-angled, the
surface dark brown to nearly black, glabrous, finely pebbled or faintly
irregular. About 300 species, nearly worldwide (but absent from southeastern
Asia to Austalia), most diverse in temperate or mountainous regions of the
northern hemisphere.
Some species of Stachys
are cultivated as ornamentals for their foliage or flowers, including the
Mediterranean S. byzantina C. Koch (lamb’s ears), which has densely
white-woolly leaves and dense spikes of pink flowers, and the bright
red-flowered S. coccinea Ortega (Texas betony, scarlet hedge nettle), which
is native to the southwestern United States and Mexico.
The Missouri
species of Stachys are morphologically variable and difficult to
distinguish. The present treatment has benefited greatly from an unpublished
review of the genus prepared by Stacy Oglesbee, an undergraduate intern in 1991
at the Missouri Botanical Garden.