Atriplex argentea |
Atriplex dioica |
|||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
maidenhair spleenwort, silver orach, silver orache, silver saltbush, silverscale, silverscale orache, silverscale saltbush, silvery orache |
rillscale, saline orache, saline saltbush, spike saltbush, thick-leaf orache, thickleaf orach, thinleaf orache |
|||||||||||||||||
Habit | Herbs, simple or freely branched, 0.5–6 dm; branches rather stout, angled, scurfy when young. | Herbs, monoecious, typically erect and often branching, 3–15 dm; stems green or striped, angular. | ||||||||||||||||
Leaves | often opposite proximally, petiolate or distal bracteate ones subsessile, blade lance-ovate, lanceolate, deltoid, or cordate, 5–75 × 4–50(–75) mm, base subhastate or obtuse to acute, margin entire or essentially so, sometimes closely repand-dentate, apex obtuse to acute or rounded, scurfy (glabrous). |
opposite or subopposite at least proximally; petiole 1–3 cm; blade strongly 3-veined from near base, lanceolate to linear-lanceolate or often triangular-ovate or lance-ovate, 30–125 × 25–60(–80) mm, thickened, basal or subbasal lobes spreading to mainly antrorse, obtuse, blade otherwise entire to sparingly dentate, typically scurfy. |
||||||||||||||||
Flowers | in axillary glomerules and terminal, interrupted spikes. |
in terminal or terminal on lateral branches, in spiciform spikes, 2–9 cm, naked except at base. |
||||||||||||||||
Staminate flowers | borne in distal axils, or in short dense spikes or panicles, or intermixed with pistillate, with 4–5-parted calyx. |
|||||||||||||||||
Seeds | brown, 1.5–2 mm wide; radicle superior or lateral. |
ellipsoid, wider than long, dimorphic: brown, 1.5–3 mm wide, flattened at base, or black, 1–2 mm wide, shiny; radicle inferior. |
||||||||||||||||
Fruiting | bracteoles sessile, subsessile, or stipitate (stipe 0.5–5 mm), cuneate-orbicular, (2.5–)4–11.2 × 2–8.8(–14) mm, margin foliaceous below apex, subentire or dentate to laciniate, face smooth, tuberculate, or crested, processes sometimes again toothed, teeth then aligned with axis of process. |
bracteoles green, blackening in age, sessile, veined or veins obscure, broadly triangular to ovate, 3–10 mm, thick, usually longer than wide, base truncate to obtuse, margin united at base, apex acute lateral angles entire or with short, sharp teeth, faces smooth or with 2 tubercles, with an inflated inner spongy layer. |
||||||||||||||||
2n | = 18, 36, 54. |
= 36, 54. |
||||||||||||||||
Atriplex argentea |
Atriplex dioica |
|||||||||||||||||
Phenology | Flowering summer–fall. | |||||||||||||||||
Habitat | Sea beaches, other saline habitats | |||||||||||||||||
Elevation | 0-1500 m (0-4900 ft) | |||||||||||||||||
Distribution |
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; BC; MB; SK; Mexico
|
AZ; CA; CO; IA; ID; KS; MA; ME; MN; MT; ND; NE; NH; NJ; NM; NV; OK; OR; RI; SD; UT; WA; WY; AB; BC; MB; NF; NS; NU; ON; QC; SK; YT
|
||||||||||||||||
Discussion | Varieties 5 (5 in the flora). Herbarium materials have tended to represent a catchall for annual specimens not readily assignable to other taxa. Indeed, the distinguishing features of the Atriplex argentea complex are shared singly and often in combination with other taxa. Only by use of combinations of features can this taxon be defined. Those features, with much variation, center around the broad, typically ovate to deltoid leaf blades (often definitely 3-veined) and more-or-less compressed, sessile to subsessile (or short stipitate), fruiting bracteoles on which the marginal processes, or teeth, are mainly aligned with the plane compression, and with the faces quite smooth to variously appendaged. Still some specimens are apparently intermediate with other species, especially with the closely allied A. saccaria, with which it is at least partially sympatric. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The distribution of the species is evidently bipartite, with an eastern coastal series extending northward mainly from New Jersey to Newfoundland and along the St. Lawrence seaway, and perhaps extending to James Bay of Hudson Bay. The western grouping lies mainly west of the 95th meridian of longitude, where it has been collected since early historical times to the present in saline marshes or other saline sites from the Yukon Territory and Northwest Territories, southward to southern California, northern Arizona, northern New Mexico, and Oklahoma. Rafinesque gave the following information: “Stem upright angular branched, leaves petiolate, deltoid, acute, thick, scaly, the proximal opposite toothed, the distal alternate, hastated, entire: flowers dioical glomerate, male spiked naked, female unequal, sepals deltoid, warty-crested.” The name Atriplex dioica Rafinesque antedates Chenopodium subspicatum Nuttall by half a year, being published in December 1817. Hence, it is the correct name for the widely ranging species, which has passed most recently under the name A. subspicata. Nuttall’s description of the habitat of Chenopodium subspicatum is: “In saline soils around Mandan Village, Missouri,” a designation of habitat that applies to this day. The species forms a mirror-image set of specimens with the remarkably similar Atriplex prostrata, from which it may be distinguished in most cases by the thickened, merely ovate to lanceolate leaf blades, and less commonly but in some localities exclusively triangular-hastate to lanceolate, mostly scurfy and prominently 3-veined leaf blades. In some specimens, including the types of both Chenopodium subspicatum and Atriplex carnosa, the blades bear a hastate lobe at or above the base and sometimes match triangular-hastate profile of A. prostrata. The leaves of A. prostrata are typically thin-textured, green, not scurfy, and the veins of the blade are obscure. I. J. Bassett et al. (1983) disallowed within A. dioica (as A. subspicata) any but those with lanceolate blades, including those with the proximalmost leaves with a pair of subbasal hastate lobes. However, there are numerous specimens in which the blades are thickened and transitional in that regard to the triangular-hastate profile as in A. prostrata. Certainly those specimens with triangular or triangular-hastate leaves taken prior to the introduction of A. prostrata sometime late in the nineteenth or early twentieth century, clearly belong to the indigenous A. dioica. Whether there are intermediates between diploid (2n = 18) A. prostrata and tetraploid or hexaploid (2n = 36, 54) A. dioica is not known. There does not seem to be any consistent feature or combination of features by which all specimens can be assigned to one or the other of the two taxa. It seems probable, however, that A. prostrata is a late introduction from Europe, and that it, along with the related A. heterosperma, is now invading habitats previously occupied exclusively by the indigenous A. dioica. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||
Key |
|
|||||||||||||||||
Source | FNA vol. 4. | FNA vol. 4. | ||||||||||||||||
Parent taxa | Chenopodiaceae > Atriplex > subg. Obione > sect. Obione > subsect. Argenteae | Chenopodiaceae > Atriplex > subg. Atriplex > sect. Teutliopsis | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Obione argentea | A. patula var. subspicata, A. subspicata | ||||||||||||||||
Name authority | Nuttall: Gen. N. Amer. Pl. 1: 198. (1818) | Rafinesque: Amer. Monthly Mag. & Crit. Rev. 2(2): 119. (1817) | ||||||||||||||||
Web links |
|