Chenopodium missouriense Aellen

Jonsell, B., Karlsson, 2005, Chenopodiaceae - Fumariaceae (Chenopodium), Flora Nordica 2, pp. 4-31 : 23

16. Chenopodium missouriense Aellen

Aellen, Bot. Not. 1928:206 (1928).

- C. album var. missouriense (Aellen) Bassett & Crompton (1982) .

- Type: USA, Missouri, Courtney, 22.X.1922 Bush 7402 (US) lectotype, sei. by Bassett & Crompton, Can. J. Bot. 60: 604 (1982).

F missourinsavikka. N hønsemelde. S hönsmålla.

Literature. Dvorak 1987.

Therophyte (summer-annual). Up to 70(-150) cm, ± farinose. Stem subangular to angular, striped with greyish to bluish green, sometimes with red colour in the leaf axils, hard, erect, richly branched; branches long, ascending. Leaf-blades dark pure green, relatively narrow, rhombic, sometimes slightly 3-lobed, in middle leaves to 8 cm; margin coarsely serrate with acute teeth; apex acute.

Inflorescences largely ebracteate, spike-like; glomerules small, compact. Flowers bisexual or female. Tepals 5, connate halfway, ± farinose, keeled, with narrow membranous margin and acute apex. Stamens 5. Stigmas 2. Nut falling with the perianth; pericarp thin, easily detached. Seed horizontal, almost orbicular in outline, 1-1.2 mm, edge slightly keeled; seed-coat black, glossy, faintly radially striate. - Late autumn.

[2n=54]

Habitat and distribution. Casual: tips, ports, granaries, mills and poultry farms, often brought in with American maize, sunflower or soybean. Collected regularly since the 1950's; the first record is from 1917. - D 0Jy Arhus 1928, 1975, Sjce c. 5 localities in the København area 1917-76, LFM Nykøbing 1961. N scattered records from the coastal provinces north to SF; ST Skaun 1934 (mill). S Sk Teckomatorp 1931-32, Hl Älvsåker 1965, BhG several localities in the Göteborg area 1927-68, Srm Nacka 1929. F at least V Naantali 1975, 1979 (granary, docks), Raisio 1947 (unloading place), Turku 1959 (docks), U Helsinki 1930, 1964 (dump), 1974-76 (oil plant harbour), EP Vaasa 1931, PH Jyväskylä 1956 (warehouse), KP Ylivieska 1953 (granary).

North America; a frequent anthropochore in Europe.

Biology. In Norden flowering late and rarely found with ripe seeds.

Chenopodium album var. album

Chenopodium missouriense

Taxonomy. Chenopodium missouriense is here taken in a wide sense to cover much of the material brought in from North America. With this circumscription it is probably heterogeneous (cf. Dvorak 1987).

Similar taxa. Chenopodium missouriense is similar to C. album (15) and C. virgatum (rare casual); see these taxa. C. berlandieri (19), another taxon from North America, differs from C. missouriense in the honeycomb-pitted seeds; in the vegetative state it can be distinguished by its yellowish stem and the smaller, less toothed, sometimes 3-lobed, apiculate leaves.