Stachys aspera Michx. - Rough Hedge Woundwort
Systematic position.Family Lamiaceae, genus Stachys L.
Synonyms.Stachys baicalensis Fisch. ex Benth., Stachys chinensis Bunge ex Benth., Stachys japonica Miq., Stachys palustris subsp. aspera (Michx.) Derviz-Sokolova, Stachys riederi Cham.
Biological group.Perennial rhizome weed.
Morphology and biology.Entire plant is covered with sparse, bristly hairs. Rhizome is thin. Stems are erect, single or ramified, covered with long, bristly, downward-pointing hairs, tetrahedral, 40-80 cm tall. Upper leaves are sessile; lower leaves are short petiolate, narrow-lanceolate, rounded or slightly cordate at the base, 3-8 cm in length and 1 cm in width, serrate-crenate, with sparse or plentiful pressed, bristly hairs on both sides. Bracts are narrow-lanceolate, almost full. Calyx is wide-belled or tubular-belled, covered with bristly hairs; its teeth are equal to the tube in length or shorter, triangular, with long, subulate points 1-1.5 mm in length. Corolla is pinkish violet, 10-12 mm in length; its upper labia is shorter than lower one, rounded, fluffy-haired; the lower labia has wide-rounded middle lobe and short, oblong, rounded lateral lobes; flowers are located in whorls. Whorls are gathered in sparse spike-shaped inflorescences. Nutlets are 2.0-2.5 mm in length, 1.2-1.5 mm in width, rounded-trihedral, spotted. Nutlets range from brown to black in color, with lighter spots. The mass of 1000 nutlets is 1.5 g. Flowering period occurs in June-August.
Distribution.Weed occurs throughout Mongolia, China, Eastern Siberia, and the Far East.
Ecology.Prefers rather moist locations. Grows well in clay loams. Shoots emerge at a minimum temperature of +8-10°C.
Economic significance.Weed of grain, tilled crops, and soy. Occurs in wastelands and along roads. Control measures include multi-field crop rotations, plowing of stubble, harrowing of winter crops, inter-row cultivation of tilled crops, and chemical weeding.
Related references:Buch, T.G., Kachura, N.N., Shvydkaya, V.D., & Andreeva, E.R. 1981. Weed plants of the Primorskii Territory and their control. Vladivostok: Dal'nevostochnoe Publishing House, 243 p. (in Russian).
Nikitin, V.V. 1983. Weed plants of the USSR flora. Leningrad: Nauka, 454 p. (in Russian).
Shishkin, B.K., ed. 1954. Flora of the USSR. V.21. Moscow-Leningrad: AN SSSR, 704 p. (in Russian).
Ulyanova, T.N. 1998. Weed plants in the flora of Russia and other CIS states. St. Petersburg: VIR, 344 p. (in Russian).