- Name also: Hastate Orache, Triangle Orache (USA)
- Family: Amaranth Family – Amaranthaceae
(formerly Goosefoot Family – Chenopodiaceae)
- Growing form: Annual herb.
- Height: 10–70 cm (4–30 in.).
- Flower: Male flower: perianth yellowish, regular, ca 1 mm (0.04 in.) across, perianth-segments 4 or 5. Stamens 5. Female flower: lacks perianth, enclosed by two erect, mealy bracts which are almost stalkless, 2–7 mm (0.08–0.3 in.) long, and have entire to toothed margins and smooth or toothed dorsal surface. Carpels fused, gynoecium 2-styled.
- Leaves: Lowermost leaves opposite, upper ones alternate. Blade triangular, margins crenate to almost entire. Upper leaves densely covered with glandular hairs, with base of blade almost straight or broadly wedge-shaped, basal teeth lobe-like.
- Fruit: Achene enclosed by and united with 2 erect bracteoles.
- Habitat: On seashores particularly on seaweed heaps. Inland gardens, sugar beet fields, and rubbish tips.
- Flowering time: (July–)August–September.
Different oraches (Atriplex spp.) are difficult to distinguish between. Oraches are very similar to species of genus Chenopodium from which they can, however, be separated by that they have unisexual flowers (they are monoecious or rarely dioecious) and characteristic fruit-enclosing bracteoles. The appearance of these bracteoles is also among the best distinguishing characters within genus Atriplex.
Spear-leaved orache is an annual native to Finland. It is a highly variably seashore species. It can be distinguished from common orache (A. patula) by the preferred habitats and often also the shape of the leaves. The base of the leaves of spear-leaved orache is straight or broadly wedge-shaped, and the basal lobes are incised. The basal leaf-lobes of common orache often point forward. Unlike common orache, the fruit-enclosing bracts of spear-leaved orache are often untoothed.