Atriplex coulteri |
Atriplex pentandra |
|
---|---|---|
Coulter's orach, Coulter's orache, Coulter's saltbush |
seas hore orach |
|
Habit | Herbs, perennial, sometimes flowering as an annual, spreading 0.7–10 dm, slightly woody at base. | Herbs, annual or perennial, sprawling to erect, often suffrutescent at the base, much branched and clump-forming, 3–10 dm. |
Stems | frequently tinged with red, much branched, sparsely scurfy. |
obtusely angled, finely scurfy when young. |
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. |
sessile or short petiolate; blade paler abaxially, oblong or rhombic-ovate to broadly obovate or narrowly oblong or narrowly elliptic, 10–30 × (1–)3–15 mm, thin, base rounded to cuneate, margin repand-dentate or sinuate-dentate to undulate or distal ones or all of them entire, apex rounded to acute, mucronate, densely white scurfy abaxially, grayish green and usually glabrate adaxially. |
Staminate flowers | in glomerules in distal axils and short terminal spikes. |
in short, dense, naked terminal spikes or panicles; calyx 5-cleft, lobes green keeled. |
Pistillate flowers | in small axillary clusters. |
fascicled in axils. |
Seeds | brown, 1.3–1.5 mm. |
brown, 1–1.5 mm. |
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. |
bracteoles sessile or with stipes to 0.5 mm, broadly cuneate-orbiculate, compressed, (2–) 2.5–4.5 × (1.5–)2.6–5 mm, usually as broad as or broader than long, much thickened at maturity, united only at truncate or broadly cuneate base, margin deeply and acutely dentate, faces with 2, sometimes swollen, dentate crests or covered with irregular, conic-acute, corky tubercles, seldom smooth. |
Atriplex coulteri |
Atriplex pentandra |
|
Phenology | Flowering spring–fall. | Flowering summer–fall. |
Habitat | Somewhat alkaline or clay low places, valley grasslands, coastal sage scrub, coastal slopes | Sandy seashores, coastal salt marshes |
Elevation | 0-500 m (0-1600 ft) | 0-50 m (0-200 ft) |
Distribution |
CA
|
AL; CT; FL; GA; LA; MA; MS; NC; SC; TX; West Indies; South America (Venezuela and Colombia to Peru) |
Discussion | 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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
D. S. Correll and M. C. Johnston (1970), treated both Atriplex texana and A. wardii at the specific level. The diagnostic features used to distinguish them, dentate versus entire leaf blades and smooth versus tuberculate faces of fruiting bracteoles, fail singly and in combination. Both taxa were regarded by H. M. Hall and F. E. Clements (1923) as variants of typical A. pentandra, and this worker tentatively agrees with those authors’ conclusions. Specimens from Galveston, Texas—the type locality of A. wardii—are apparently intermediate with A. mucronata (see below) and form the basis on which A. wardii was founded. Some of those specimens have been annotated by me and others as A. mucronata. The plants have entire leaves more closely matching those of A. mucronata, but the small fruiting bracteoles, though usually lacking tubercles on the faces, are of similar proportions to those of typical A. pentandra. Atriplex pentandra and A. mucronata are certainly very closely allied. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 363. | FNA vol. 4, p. 362. |
Parent taxa | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Arenariae | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Arenariae |
Sibling taxa | ||
Synonyms | Obione coulteri | Axyris pentandra, A. texana, A. wardii |
Name authority | (Moquin-Tandon) D. Dietrich: Syn. Pl. 5: 537. (1852) | (Jacquin) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 54. (1916) |
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