Coulter’s orach

Obione coulteri Moquin-Tandon in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 113. 1849

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.

Flowering spring-fall. Somewhat alkaline or clay low places, valley grasslands, coastal sage scrub, coastal slopes; of conservation concern; 0-500 m; Calif.

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.