Oxybasis glauca (L.) S. Fuentes, Uotila & Borsch

In Great Britain and/or Ireland:
Foodplant / parasite
sporangium of Peronospora farinosa parasitises live Chenopodium glaucum
Other: unusual host/prey

Annual up to 70 cm, branched from the base, sometimes forming cushion-like habit at high elevations; stem often prostrate to ascending, rarely straight. Leaves up to 6 × 2 cm, petiolate, cuneate at base, oblong or lanceolate, dentate or lobate with 2–5 lobes, rarely entire, green adaxially, grey or whitish below. Inflorescence leafy, loose. Perianth segments 3 to 5, almost free with hyaline margins, keeled along midrib, opened at fruiting stage. Fruit 0.65–0.8 mm in diameter, pericarp smooth, whitish, often ruptured. Seed reddish, without keel; embryo in both vertical and horizontal positions (spatial heterospermy), structural (latent) heterospermy expressed in different thickness of seed-coat testa.

Annual up to 70 cm, basally branched with ascending stems. Leaves triangular, oblong or rhombic-triangular, entire or dentate, sometimes with two marginal lobes; upper leaves lanceolate. Inflorescence leafy in lower part. Female flowers in axillary clusters and intermixed with male flowers forming terminal inflorescences. Bract-like cover enclosing the female flowers sessile or shortly pedunculate (peduncles up to 3.0 mm), ovate, rhombic or triangular, 1.2–5.0(7.0) mm long, sclerified but not or slightly inflated, entire or dentate, usually without outgrowths on the back. Seeds heteromorphic: red seeds convex, 0.7–1.2 mm in diameter, brown seeds 1.2–1.8 mm, flattened.

See Fig. 15.

See Fig. 16.

Oxybasis glauca (syn. Chenopodium glaucum), common name oak-leaved goosefoot, is a species of goosefoot plant native to Europe. It has been introduced and become an invasive weed in North America. This invader of European origin also appears in trampled communities in North Korea.