- Name also: Grass-leaved Orache, Shore Orache, Tropical Saltbush
- Family: Amaranth family – Amaranthaceae
(formerly Goosefoot Family – Chenopodiaceae)
- Growing form: Annual, unisexual, dioecious herb.
- Height: 40–100 cm (16–40 in.). Stem erect, bristly, green–reddish, abundantly branching.
- Flower: Flowers modest, unisexual. Staminate flowers with 5-lobed perianth. Stamens 5. Pistillate flowers lacking perianth, enclosed by 2 erect, mealy bracts, stalkless in the clustered flowers, stalked in singly-borne flowers. Bracts almost stalkless, 2–7 mm (0.08– 0.28 in.) long, many-veined, toothed from edge and back or glossy (entire). Styles 2. Inflorescence narrow, spike-like, upper part leafless.
- Leaves: Opposite, short-stalked, linear, 5–10 cm (2– 4 in.) long, usually juicy, greyish green, sparse-toothed–entire margins.
- Fruit: Achene enclosed by fruit calyx. Fruit calyx with 2 fused sepals (bracteoles). Sepals triangular, with toothed margins, 2–8 mm (0.08– 0.32 in.) long, surface with sharp-tipped, thick-based teeth. Seed black, shiny, 1.5–3 mm (0.06 –0.12 in.).
- Habitat: Sea shores, especially sandy areas and seaweed piles, harbours.
- Flowering time: July–September.
Genus Atriplex is a difficult group from the point of view of identifying the species. The genus is easily confused with genus Chenopodium, but they can be told apart by the fact that Atriplex species are unisexual (in the case of grassleaf orache dioecious) but Chenopodium species are bisexual and the former’s fruits typically have 2 partly joined bracteoles (Chenopodium species do not). The characteristics of these bracteoles are important for identifying the species within genus Atriplex.
Grassleaf orache is a coastal plant which can be found in Finland a far north as Vaasa. Other coastal members of the genus include spear-leaved orache (A. prostrata), long-stalked orache (A. longipes), hastate orache (A. hastata) and glabrous orache (A. glabriuscula). Of these, grassleaf orache is perhaps the easiest to identify as it’s relations don’t have such narrow leaves. Grassleaf orache can be confused with the rare desert goosefoot (Chenopodium pratericola), although the latter’s leaves are more mealy, relatively wider and it doesn’t grow in coastal areas at all.