Atriplex coulteri

(Moquin-Tandon) D. Dietrich

Syn. Pl. 5: 537. 1852.

Common names: Coulter’s orach
EndemicConservation concern
Basionym: Obione coulteri Moquin-Tand on in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 113. 1849
Treatment appears in FNA Volume 4. Treatment on page 363. Mentioned on page 325, 364.

Herbs, perennial, sometimes flowering as an annual, spreading 0.7–10 dm, slightly woody at base. Stems frequently tinged with red, much branched, sparsely scurfy. Leaves many, sessile or short petiolate; blade obovate, oblong, oblanceolate, or elliptic, (5–)7–20 × 1–3(–5) mm, base cuneate, margin entire, apex acute. Staminate flowers in glomerules in distal axils and short terminal spikes. Pistillate flowers in small axillary clusters. Fruiting bracteoles sessile or subsessile, broadly obovate, 2–3 mm and as broad or about as broad, united 1/2 of length, margin free, deeply and sharply dentate, narrowed at summit, faces smooth or sometimes tuberculate. Seeds brown, 1.3–1.5 mm.

Phenology: Flowering spring–fall.
Habitat: Somewhat alkaline or clay low places, valley grasslands, coastal sage scrub, coastal slopes
Elevation: 0-500 m


Of conservation concern.

Atriplex coulteri is closely allied to the geographically disjunct A. fruticulosa, from which it is said to differ in the compressed, small (2.5–3 mm) versus thickened and larger (3–5 mm) bracts. Specimens of A. fruticulosa, including the type, examined by me have bracteoles compressed-thickened, but hardly “globoid” as stated in the key to the species by H. M. Hall and F. E. Clements (1923). Additional specimens borrowed from California might clarify the situation; otherwise the two species are sufficiently close as to be treated as a single entity.

Selected References


Lower Taxa

... more about "Atriplex coulteri"
Stanley L. Welsh +
(Moquin-Tandon) D. Dietrich +
Obione coulteri +
Coulter’s orach +
0-500 m +
Somewhat alkaline or clay low places, valley grasslands, coastal sage scrub, coastal slopes +
Flowering spring–fall. +
Endemic +  and Conservation concern +
Atriplex sect. Obione +
Atriplex coulteri +
Atriplex subsect. Arenariae +
species +