Stachys annua L. - Annual Woundwort
Systematic position.Family Lamiaceae, genus Stachys L.
Synonyms.Stachys neglecta Klok. ex Kossko.
Biological group.It is an annual spring or winter weed.
Morphology and biology.Plant is 15-35 cm tall; stems are simple or ramified, often hairless at base, with soft, short, downwardly directed hairs at top, with denser hairs under inflorescences. Lower leaves are wedge-shaped at base, oblong-ovate, crenate; upper leaves are lanceolate, sharp, serrated; top leaves are reduced, sessile. Bracts are filiform or linear, long-ciliated. Inflorescence is long, spike-shaped; two or three lower whorls are sparse; upper whorls are connivent. Calyx is somewhat hairy; its teeth are triangular-lanceolate, becoming spiniform upward, arcuate, as long as tube. Corolla is whitish-yellowish, two times longer than calyx; upper labia rounded; lower labia has emarginated middle lobe and rounded-ovate lateral lobes. Seeds are widely-ovate, obtuse-trihedral, fine-meshed. The mass of 1000 seeds is 0.75-1.25 g. The maximal fecundity of one plant is 26,400 seeds. Seeds germinate from depths of not more than 6 cm. The flowering period occurs in June-August.
Distribution.Western Europe, Asia Minor, North America, European part of the former USSR, the Caucasus, Western Siberia, Eastern Siberia.
Ecology.It prefers clay and lime soils. Shoots emerge at the minimum temperature of +6-8°C and at the optimum of +22-24°C.
Economic significance.Weed of grain and tilled crops, occurs in fallow lands, kitchen gardens, waste lands, along roads. Control measures include the plowing-in of stubble, harrowing of winter crops, inter-row cultivation of tilled crops and chemical weeding.
Reference citations:Mal.tsev A.I. 1939. Atlas of major species of weed plants of the USSR. V.2. Moscow-Leningrad: Selkhozgiz. 88 p. (In Russian)
Shishkin, B.K., ed. 1954. Flora of the USSR. V. 21. Moscow-Leningrad: AN SSSR. 704 p. (In Russian)
Veselovs.kii I.V., Lisenko A.K., Man.ko Yu.P. 1988. Atlas-synopsis of weeds. Kyiv: Urozhai. 72 p. (in Ukrainian).
Volkov A.N., ed. 1935. Areas of distribution of the major weed plants in the USSR. Moscow-Leningrad: State Publishing House of Kolkhoz and Sovkhoz Literature. 152 p. (In Russian)