Weeds

Corispermum declinatum Steph. ex Iljin - Bugseed

Systematic position.

Family Chenopodiaceae Vent., genus Corispermum L.

Biological group.

Annual spring weed.

Morphology and biology.

Plant is 15-50 cm in height, green or more often reddish, glabrous or with scattered thin hairs mainly on the young plant parts, divaricate and branched from the very base, forming a type of "tumbleweed". Leaves are long, narrow, linear, flat or slightly concave from above, pointed, gradually transforming to lanceolate on the long narrow spiciform inflorescence, widely white-filmy along the edges, green in the middle bracts. They exceed the size of fruits by several times; remain at the fruits, covering them totally. Perianth is filmy, consisting of usually one leaflet, serrated or incised along the edges. Utricles are oblong or ovate, twice as long as wide, glabrous, olive-colored, lustreless, with narrow entire or slightly flexuous non-transparent wings differing in color from the utricle. Red forms of the plant have almost purple wings. The plant flowers and bears fruits from June until September. C. declinatum propagates by seeds.

Distribution.

Mongolia, North China. Within the Former Soviet Union the plant occurs in the European part (Volga left-bank), in southern parts of Western and Eastern Siberia, in northern Kazakhstan.

Ecology.

C.declinatum prefers sandy-loam soils of forest-steppe and steppe zones. It grows in clusters.

Economic significance.

C.declinatum mainly infests spring grain crops, for the most part developing in the third layer and abundantly infesting soil with its seeds. This plant grows in masses in fallows of steppe zone. It also occurs in sandy steppes, dry exhausted pastures, lea lands and waste places. Control measure: soil cultivation.

Reference citations:

Anonym. 2004. Corispermum declinatum. Flora of China: http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200006832
Fedchenko, B.A., ed. 1930. Flora of South-East of the European part of the USSR. Issue 4. Leningrad: Main Botanical Garden. 360 p. (in Russian).
Golubintseva, V.P. 1936. The specific weeds of Siberia. In: Reverdatto, V.V., ed. Transactions of Biological Institute of Tomsk State University. V.2. Tomsk: Tomsk State University. p.170-227. (in Russian).
Keller, B.A., ed. 1934. Weed plants of the USSR. V.2. Leningrad: AN SSSR. 244 p. (in Russian).
Komarov, V.L. & Shishkin, B.K., eds. 1936. Flora of the USSR. V.6. Moscow-Leningrad: AN SSSR. 954 p. (in Russian).
Nikitin, V.V. 1983. Weed plants of the USSR flora. Leningrad: Nauka. 454 p. (in Russian).
Volkov, A.N., ed. 1935. Areas of distribution of the major weed plants in the USSR. Moscow-Leningrad: Publishing House of Kolchoz & Sovchoz Literature. 153 p. (in Russian).

© S.Yu.Larina

The image of Corispermum declinatum is taken from Fedchenko, B.A., ed. (1930) "Flora of Southeast of the European part of the USSR", issue 4 (Leningrad: Main Botanical Garden, 360 p.).