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seas hore orach

Watson's orach, Watson's saltbush

Habit Herbs, annual or perennial, sprawling to erect, often suffrutescent at the base, much branched and clump-forming, 3–10 dm. Herbs, dioecious, prostrate or decumbent, 2–10 dm.
Stems

obtusely angled, finely scurfy when young.

forming tangled mats 1–3 m across, woody at base, white scurfy.

Leaves

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.

numerous, mostly opposite;

blade broadly elliptic to ovate, 8–25 mm, often surpassing internodes, thick and fleshy (when fresh), margin entire, apex acutish, white scurfy.

Staminate flowers

in short, dense, naked terminal spikes or panicles;

calyx 5-cleft, lobes green keeled.

in large glomerules in naked, interrupted terminal spikes;

calyx 5-cleft.

Pistillate flowers

fascicled in axils.

in small, axillary clusters.

Seeds

brown, 1–1.5 mm.

light brown, 1–1.5 mm.

Fruiting

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.

bracteoles sessile or short stipitate, ovate to rhombic, united to beyond middle, 4–8 mm, margin entire to erose, faces plane.

Atriplex pentandra

Atriplex watsonii

Phenology Flowering summer–fall. Flowering spring–fall.
Habitat Sandy seashores, coastal salt marshes Coastal and insular bluffs, beaches, strands, salt marshes, sage scrub, with saltgrass and other salt-tolerant species
Elevation 0-50 m (0-200 ft) 0-100 m (0-300 ft)
Distribution
from FNA
AL; CT; FL; GA; LA; MA; MS; NC; SC; TX; West Indies; South America (Venezuela and Colombia to Peru)
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Atriplex watsonii is a sprawling plant that exhibits much variation in leaf size, as attested in the clearly staminate type collection, Palmer 334, wherein the range in size is from 5–25 × 2.5–11 mm wide. Although typically placed adjacent to A. matamorensis, the other dioecious perennial, the two taxa are probably not closely allied. The broader-leaved phases simulate closely A. leucophylla, with which it is sometimes confused, and perhaps the relationship lies in that direction, but it closely simulates A. californica, with which it is probably most closely allied.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 4, p. 362. FNA vol. 4, p. 367.
Parent taxa Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Arenariae Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Californicae
Sibling taxa
A. acanthocarpa, A. amnicola, A. argentea, A. californica, A. canescens, A. confertifolia, A. cordulata, A. coronata, A. corrugata, A. coulteri, A. covillei, A. dioica, A. elegans, A. fruticulosa, A. gardneri, A. garrettii, A. glabriuscula, A. gmelinii, A. graciliflora, A. heterosperma, A. holocarpa, A. hortensis, A. hymenelytra, A. joaquiniana, A. klebergorum, A. laciniata, A. lentiformis, A. leucophylla, A. lindleyi, A. linearis, A. littoralis, A. matamorensis, A. mucronata, A. nudicaulis, A. nummularia, A. oblongifolia, A. obovata, A. pacifica, A. parishii, A. parryi, A. patula, A. phyllostegia, A. pleiantha, A. polycarpa, A. powellii, A. prostrata, A. pusilla, A. rosea, A. saccaria, A. semibaccata, A. serenana, A. spinifera, A. suberecta, A. suckleyi, A. tatarica, A. torreyi, A. truncata, A. tularensis, A. watsonii, A. wolfii, A. wrightii
A. acanthocarpa, A. amnicola, A. argentea, A. californica, A. canescens, A. confertifolia, A. cordulata, A. coronata, A. corrugata, A. coulteri, A. covillei, A. dioica, A. elegans, A. fruticulosa, A. gardneri, A. garrettii, A. glabriuscula, A. gmelinii, A. graciliflora, A. heterosperma, A. holocarpa, A. hortensis, A. hymenelytra, A. joaquiniana, A. klebergorum, A. laciniata, A. lentiformis, A. leucophylla, A. lindleyi, A. linearis, A. littoralis, A. matamorensis, A. mucronata, A. nudicaulis, A. nummularia, A. oblongifolia, A. obovata, A. pacifica, A. parishii, A. parryi, A. patula, A. pentandra, A. phyllostegia, A. pleiantha, A. polycarpa, A. powellii, A. prostrata, A. pusilla, A. rosea, A. saccaria, A. semibaccata, A. serenana, A. spinifera, A. suberecta, A. suckleyi, A. tatarica, A. torreyi, A. truncata, A. tularensis, A. wolfii, A. wrightii
Synonyms Axyris pentandra, A. texana, A. wardii A. decumbens
Name authority (Jacquin) Standley: in N. L. Britton et al., N. Amer. Fl. 21: 54. (1916) A. Nelson ex Abrams: Fl. Los Angeles, 128. (1904)
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