1. Plants perennial shrubs [20c. Atriplex subg. Pterochiton, in part] | Key 4 |
1. Plants annual or perennial herbs | → 2 |
2. Leaves usually green on both surfaces, glabrous or sparingly powdery or finely scurfy | Key 1 |
2. Leaves white to gray, densely and finely scurfy, especially adaxially | → 3 |
| Key 2 |
| Key 3 |
1. Pistillate flowers of 2 kinds: some with calyx 3-5-lobed and seed horizontal, others lacking perianth, enclosed in pair of bracteoles, seed vertical; fruiting bracteoles samaralike, strongly compressed, oval to orbicular or ovate; plants widespread in North America [20a.1. Atriplex sect. Atriplex] | A. hortensis |
1. Pistillate flowers all alike or, if dimorphic, both kinds lacking perianth, enclosed within bracteoles, and seed vertical; fruiting bracteoles variously compressed (orbicular in A. heterosperma) | → 2 |
2. Bracteoles ± thickened with spongy tissue, especially toward base [20a.2. Atriplex sect. Teutliopsis] | → 3 |
2. Bracteoles not thickened (except A. joaquiniana) | → 7 |
3. Lower leaves linear or ovate-lanceolate, sometimes toothed and/or with proximalmost lobe largest, but then not triangular, or if so leaves thick textured | → 4 |
3. Lower leaves (sometimes all or most) triangular and thin textured | → 5 |
4. Leaves linear to lanceolate or oblong, thin, green or slightly scurfy when young; seeds ovoid, not wider than long; coastal e Canada and ne United States, w disjunctly to Pennsylvania, Ohio, and Indiana | A. littoralis |
4. Leaves ovate-lanceolate or linear, or triangular or triangular-hastate, typically thickened and ± scurfy, even in age; seeds ellipsoid, wider than long; broad distribution from coastal e Canada and United States, and c and w United States | A. dioica |
5. Bracteoles, some or all, short stipitate, margin irregularly denticulate to laciniate, lateral angles of faces usually developed into 1-3 teeth; Cape Breton coast, Newfoundland, Nova Scotia, and New Brunswick | A. glabriuscula |
5. Bracteoles all sessile, margin entire or slightly toothed, lateral angles shortly pointed but not definitely toothed; geography below | → 6 |
6. Inflorescence with leafy bracts to the tip, glomerules loose, irregularly spaced; bracteoles thick spongy, margin united to middle; seeds 2.5+ mm wide, usually not distinctly dimorphic, dark brown to black, irregularly biconvex; radicle median, ± antrorse; coastal e United States, from New Jersey n to Maine and Nova Scotia and n to Newfoundland and Labrador, and w disjunctly to Hudson Bay and n Alberta | A. glabriuscula |
6. Inflorescence with leafy bracts only at base, glomerules tight, contiguous or irregularly spaced; bracteoles thin to slightly thickened and spongy, margin united only at base; seeds mostly less than 2.5 mm wide, usually distinctly dimorphic, mostly small and glossy black, but also some larger, and dull brown, flattened and disc-shaped; radicle subbasal, obliquely antrorse to spreading; plant a weedy introduction of broad distribution in United States and s Canada | A. prostrata |
7. Plants mostly less than 1.2 dm; proximal leaves lanceolate to rhombic-ovate, bases cuneate to attenuate; bracteoles rhombic-ovate, thin herbaceous or membranaceous, entire, free to base; seeds black, lustrous, biconvex, 1.2-2.5 mm wide, with subbasal, spreading radicle; plants in the sublittoral zone on coasts of Newfoundland | A. nudicaulis |
7. Plants mostly more than 1.2 dm; proximal leaves, bracteoles, and seeds not simultaneously as above; distribution various | → 8 |
8. Fruiting bracteoles ovate to elliptic or orbiculate-cordate | → 9 |
8. Fruiting bracteoles never orbiculate-cordate, frequently toothed, usually with lateral angles | → 11 |
9. Bracteoles ovate to widely triangular, surfaces often 2-tuberculate, margin toothed; leaves usually thickened, ± scurfy, even at maturity | A. dioica |
9. Bracteoles orbiculate-ovate, surfaces smooth, margin entire; leaves usually thin, green on both sides, not or scarcely scurfy | → 10 |
10. Leaves broadly triangular-hastate; widely distributed from Quebec, w to Brit- ish Columbia and s to California, Nevada, Utah, and Colorado | A. heterosperma |
10. Leaves mostly lanceolate to narrowly hastate; s British Columbia, adjacent Alberta, and South Dakota | A. oblongifolia |
11. Bracteoles (2-)2.5-3(-4.5) mm; leaf blades deltoid to rhombic-ovate or oblong-ovate, coarsely toothed; saline soils in Sacramento Valley and east San Francisco Bay vicinity and San Joaquin Valley, California | A. joaquiniana |
11. Bracteoles mainly 4-10+ mm; leaf blades hastate or entire, lanceolate to oblong; coastal salt marshes or ruderal weedy species of broad distribution | → 12 |
12. Largest bracteoles strap-shaped or ovate-lanceolate; halophytes of w and nw coastal areas of North America | A. gmelinii |
12. Largest bracteoles ovate, ovate-triangular, or rhombic; e coastal North America (disjunctly westward) or widespread ruderal weeds | → 13 |
13. Radicle of brown seeds basal and spreading; e coastal salt marshes and disjunctly w to Hudson Bay and n Alberta | A. glabriuscula |
13. Radicle of brown seeds subbasal to median and antrorse; widespread ruderal weeds | → 14 |
14. Bracteoles rhombic, margin united almost to middle, lateral angles definite; terminal inflorescence with densely compressed, ± uniform- sized bracteoles; distal leaves green on both sides | A. patula |
14. Bracteoles ovate or triangular-ovate, margin free to base, lateral angles lacking; terminal inflorescence with loosely spaced, larger and smaller bracteoles; distal leaves whitish abaxially | A. oblongifolia |
1. Plants dioecious; leaves sessile, mostly opposite [20b.3i. Atriplex subg. Obione subsect. Californicae, for the most part] | → 2 |
1. Plants monoecious; leaves various, but if sessile and mostly opposite, of different distribution | → 3 |
2. Leaves 2-5 mm, subequal to internodes; fruiting bracteoles 2-3 mm; coastal or near coastal s Texas and adjacent Mexico | A. matamorensis |
2. Leaves 8-25 mm, often surpassing internodes; fruiting bracteoles 4-8 mm; coastal Santa Barbara County, California, Baja California, Mexico | A. watsonii |
3. Leaves sessile, blade 5-20 × 1.5-5 mm; fruiting bracteoles 3 mm, rhombic-ovate, acute, sessile, scarcely united, entire; coastal and insular Marin County, California s to Baja California, Mexico [20b.3i. Atriplex subg. Obione subsect. Californicae, in part] | A. californica |
3. Leaves subsessile to long petiolate, blade and fruiting bracteoles mostly more than 3 mm, but if shorter, not from coastal California | → 4 |
4. Fruiting bracteoles (5-)6-12 mm, fibrous and spongy or merely spongy-thickened | → 5 |
4. Fruiting bracteoles mainly 3-6 mm, not fibrous or spongy thickened | → 7 |
5. Fruiting bracteoles obovoid-globular, summit closed by 2 erect, appressed, entire or 3-toothed valves; plants known from cultivation in Wyoming and Texas [20a.4. Atriplex sect. Spongiocarpus, in part] | A. holocarpa |
5. Fruiting bracteoles variously shaped, bearing 1 or 2 appendages; different distributions | → 6 |
6. Fruiting bracteoles 5-7 mm, broadly ovate in profile, entire or dentate, usually with wartlike projections on faces; sea beaches and coastal strand, occasionally inland, from Humboldt County, California, south to Baja Cali- fornia, Mexico [20b.3h. Atriplex sect. Obione subsect. Leucophyllae] | A. leucophylla |
6. Fruiting bracteoles 6-12 mm, broadly turbinate or hemispheric, flattened at summit, bordered by a narrow horizontal wing or acutely angled; plants escaped from cultivation in San Joaquin Valley and San Diego County, California [20a.4. Atriplex sect. Spongiocarpus, in part] | A. lindleyi |
7. Seeds dimorphic: black, 1.5-1.7 mm, or brown, 2 mm; bracteoles fleshy; plants low growing, many stemmed; leaf margin irregularly dentate; introduced, sw British Columbia and Washington, to s California, s Arizona, s Nevada, sw Utah, s Arizona, s New Mexico, and Texas [20a.5. Atriplex sect. Semibaccata, in part] | A. semibaccata |
7. Seeds monomorphic, either black or brown; bracts not fleshy; plants not low growing; leaf margin entire to dentate; various or other distribution | → 8 |
8. Petioles to 1/2 as long as blades, or some blades typically more than 2.5 cm | → 9 |
8. Petioles short (much less than 1/2 as long as blades) or lacking, blades of various lengths | → 10 |
9. Fruiting bracteoles 3 mm and as wide at apex, bluntly deltoid to circular, swollen, hard, smooth, denticulate at apex, faces unappendaged; Australian species [20a.5. Atriplex sect. Semibaccata, in part, Atriplex muelleri Bentham, see 17 Atriplex semibaccata] | A. semibaccata |
9. Fruiting bracteoles (3-)5-7 mm, 2-4 mm broad, cuneate-orbicular, margin sharply dentate, faces with appendages or unappendaged; indigenous plants from nc to s California, w and s Nevada, Arizona, New Mexico, w and n Texas, w Oklahoma | A. argentea |
10. Leaves sinuate-dentate; fruiting bracteoles rhombic, widest and 2- to 4-toothed beyond middle; plants known from s California, e to s Utah [20a.5. Atriplex sect. Semibaccata, in part] | A. suberecta |
10. Leaves variously toothed or entire; fruiting bracteoles variously shaped and toothed; various or other distribution | → 11 |
11. Fruiting bracteoles 2-4 mm wide, orbicular, subsessile to short stipitate, strongly compressed, united except at thin margin, margin dentate, terminal teeth often prominent, faces smooth; Mojave and Colorado deserts, California and adjacent s Arizona | A. elegans |
11. Fruiting bracteoles, at least some, more than 4 mm, rhombic or obovate to cuneate-orbiculate, orbiculate, or obovate, margin deeply and acutely dentate, faces variously toothed or appendaged, the terminal teeth not conspicuous; various or other distribution | → 12 |
12. Faces of cuneate-orbiculate fruiting bracteoles with 2 dentate crests or covered with irregular, conic-acute, corky tubercles; sandy seashores, s Carolina to s Florida and w to coastal w Texas | A. pentandra |
12. Faces of obovate or orbiculate fruiting bracteoles without dentate crests or corky tubercles, usually smooth; saline or alkaline substrates in California, Nevada, Arizona, and Utah | → 13 |
13. Fruiting bracteoles 2-3 mm, obovate, united 1/2 of length, free margin deeply and sharply dentate, faces smooth or sometimes tuberculate; Santa Barbara and Los Angeles to w San Bernardino Counties, California | A. coulteri |
13. Fruiting bracteoles often larger, suborbiculate, or orbiculate, united except at thin margin, margin dentate, terminal teeth often prominent, faces often smooth; interior California, Nevada, Arizona, and Utah | → 14 |
14. Staminate flowers in terminal spikes, pistillate ones in axillary clusters; Sacramento and San Joaquin valleys, California | A. fruticulosa |
14. Staminate flowers in axillary clusters, or staminate and pistillate mixed, usually in axillary clusters; e of Sierra Nevada, in s California, e to Rio Grande Valley of s Texas, and s to Mexico | A. elegans |
1. Leaf blades all or most of them dentate or sinuate-dentate, leaves all alternate, or opposite only at proximalmost 1-3 nodes | → 2 |
1. Leaf blades not all dentate, some, or all, of them entire, leaves commonly opposite or subopposite at proximalmost nodes | → 6 |
2. Fruiting bracteoles widest at middle, entire below middle, 2-4-toothed beyond middle; s California [20a.5. Atriplex sect. Semibaccata, in part] | A. suberecta |
2. Fruiting bracteoles mostly widest below middle, variously toothed, tuberculate, or entire; various or other distribution | → 3 |
3. Leaf blades orbiculate or suborbiculate, flabellate to broadly obtuse at base; fruit flask-shaped in outline; Milk River Valley, Upper Missouri, south to Colorado [an Atriplex look-alike, Suckleya suckleyana (Torrey ex A. Gray) Rydberg] | → 3 |
3. Leaves mainly ovate to lanceolate, acute to obtuse basally; various distribution [20a.3. Atriplex sect. Sclerocalymma] | → 4 |
4. Plants erect; leaves with Kranz anatomy; seeds 2-2.5 mm wide; common, widespread weedy species mainly in saline substrates, widely distributed in United States and less so in s Canada | A. rosea |
4. Plants decumbent; leaves with or without Kranz anatomy; seeds 3.5-4 mm wide (1.5-2 mm in A. tatarica); rare coastal halophytes of sandy beaches bordering Gulf of St. Lawrence, Canada, and along Atlantic coast to Alabama | → 5 |
5. Seeds 1.5-2 mm; leaves without Kranz anatomy; staminate glomerules arranged in terminal panicles or spikes to several cm; plants robust, stems usually 2-15 dm, leaves often more than 5 cm; rare ballast waifs, introduced from Europe, from Massachusetts to Pennsylvania, and disjunctly in coastal Alabama | A. tatarica |
5. Seeds 3.5-4 mm; leaves with Kranz anatomy; staminate glomerules in distal axils and in short dense terminal spikes to 1 cm; plants small, stems less than 3 dm; Gulf of St. Lawrence, Canada | A. laciniata |
6. Perianth of staminate flowers cup-shaped, lobes fleshy-crested on back, pink; bracteole margin united to apex; high plains and steppes, se Alberta and s Saskatchewan, e Montana, w North Dakota, South Dakota, Wyoming, and nw Colorado [20b.2. Atriplex subg. Obione sect. Endolepis] | A. suckleyi |
6. Perianth of staminate flowers not cup-shaped, lobes ovate, rounded on back, green in center, becoming membranous near margins; bracteole margin united at base or to middle; various or other distribution | → 7 |
7. Fruiting bracteoles 3-7 mm wide, enclosing 2-5 flowers, these with perianth of 5 hyaline scales 1-1.2 mm; leaves without Kranz anatomy; mainly on Mancos Shale and Morrison formations, Four Corners vicinity, Colorado, Utah, New Mexico [20b.1. Atriplex subg. Obione sect. Pleianthae] | A. pleiantha |
7. Fruiting bracteoles of various sizes, not enclosing more than 1 flower; leaves mainly with Kranz anatomy (except A. covillei); of various or other distribution | → 8 |
8. Bracteoles on stipes 2-6 mm, body 5-6 mm thick, globose, with hornlike ap- pendages on both faces; se Utah | A. saccaria |
8. Bracteoles variously sessile or, if stipitate, not otherwise as above | → 9 |
9. Bracteoles samaralike, orbicular, often over 10 mm, margin 2-4 times as wide as body; staminate flowers in deciduous terminal panicles; local in e Utah, and wc Colorado | A. graciliflora |
9. Bracteoles commonly less than 10 mm (mostly much less; 5-20 mm in A. phyllostegia), margin usually little if at all wider than body; staminate flowers in panicles or some or all in axillary glomerules; various or other distribution | → 10 |
10. Fruiting bracteoles orbicular, finely and regularly radiately dentate to base, strongly compressed; deserts in se California and e to sw Utah, s Nevada, s Arizona, s New Mexico, w Texas, and in Sonora and Chihuahua [20b.3g. Atriplex subg. Obione subsect. Arenariae, in part] | A. elegans |
10. Fruiting bracteoles not orbicular, or if so, never radiately dentate to base and not at once strongly compressed; other distribution | → 11 |
11. Leaf blades oval to ovate or ovate-lanceolate, hastate or not; w Nevada and Great Valley of California | → 12 |
11. Leaf blades variously shaped, if as above, mainly of other distribution | → 13 |
12. Leaves oval to ovate, seldom if ever with long-attenuate, hastate lobes; plants with Kranz anatomy; w Nevada [20b.4. Atriplex subg. Obione sect. Phyllostegiae] | A. phyllostegia |
12. Leaves ovate-lanceolate, mainly with acute to long-attenuate hastate lobes; plants without Kranz anatomy; w Nevada and c and s California [20b.5. Atriplex subg. Obione sect. Covilleiae] | A. covillei |
13. Bracteoles 4-7 mm wide, variably and irregularly 3-7-cleft, typically constricted near middle and with terminal lobes 1.5-2.8 mm, doubly cristate on faces or smooth; Kleberg, LaSalle, Starr, and Webb counties, s coastal Texas [20b.3c. Atriplex subg. Obione subsect. Argenteae, in part] | A. klebergorum |
13. Bracteoles less than 4-6 mm wide, or if that wide, then differing otherwise or of other distribution | → 14 |
14. Bracteoles deltoid to ovate or hastate-ovate to ovate-oblong, broadest at or near base, often about twice as long as broad, small, sparingly dentate or tuberculate, or entire or smooth, acute; leaves small, sessile, blade typically entire, ovate to linear | → 15 |
14. Bracteoles broadest near or above middle, usually rounded or truncate at apex, or if not so, leaves dentate; leaves usually large and often some petiolate (but see also A. coronata) | → 24 |
15. Leaves and/or branches opposite, at least proximalmost [20b.3f. Atriplex subg. Obione subsect. Pusillae, in part] | → 16 |
15. Leaves and branches all alternate | → 18 |
16. Plants tending to sprawl, with leaves and foliose bracts tending to recurve | A. parishii |
16. Plants erect or ascending, with leaves and foliose bracts straight or nearly so | → 17 |
17. Proximal leaves with rounded base, with both leaves and foliose bracts somewhat thickened and stiffly ascending; fruiting bracteoles 2.5-3.5 mm, ovate to rhombic; Kern Lake, s San Joaquin Valley, California | A. tularensis |
17. Proximal leaves acute to obtuse at base, with both leaves and foliose bracteoles rather thin and merely ascending; fruiting bracteoles 2.5-4 mm, broadly deltate to suborbiculate in profile; San Joaquin Valley, Kern and Fresno counties, California | A. coronata |
18. Fruiting bracteoles 1.5-2 × 1-1.5 mm, ovate-oblong, fused to near summit, tridentate apically, occasionally with marginal or less commonly with facial appendages; se Utah [20b.3c. Atriplex subg. Obione subsect. Argenteae, in part] | A. powellii |
18. Fruiting bracteoles not at once as above; various or other distribution [20b.3f. Atriplex subg. Obione subsect. Pusillae, for the most part] | → 19 |
19. Leaf blades of at least some proximalmost leaves cordate at base; nc and c California | A. cordulata |
19. Leaf blades rounded to acute or at most subcordate at base; various distribution | → 20 |
20. Branches copiously villous, at least around inflorescence | A. parishii |
20. Branches merely scurfy | → 21 |
21. Faces of bracteoles tuberculate | → 22 |
21. Faces of bracteoles smooth | → 23 |
22. Leaf blades mainly 0.4-2.5 × 0.1-0.3 cm, linear to narrowly lanceolate; fruiting bracteoles ovate to cuneate; Utah, Wyoming, and Colorado [20b.3e. Atriplex subg. Obione subsect. Wolfianae] | A. wolfii |
22. Leaf blades 0.2-0.4 × 0.1-0.3 cm, ovate to ovate-lanceolate; fruiting bracteoles ovate-oblong; Glenn, Merced, and Tulare counties, California | A. parishii |
23. Bracteoles 2-3 mm, subhastate, denticulate, or crenulate; stems mainly not suffused with red; c valley of California southward | A. parishii |
23. Bracteoles 1-2 mm, ovate, entire; stems suffused with red; ne California, se Oregon, Nevada | A. pusilla |
24. Leaf blades, most of them, deltoid to deltoid-ovate or broadly ovate, broadest at or near base (lanceolate to elliptic in A. coronata), usually entire | → 25 |
24. Leaf blades neither deltoid nor ovate, usually broadest at or beyond middle, in few species leaves broadest at base and conspicuously dentate | → 31 |
25. Leaf blades often cordate at base; fruiting bracteoles of 2 kinds on each plant; s Wyoming, e Utah, n Arizona, nw New Mexico, and w Texas [20b.3b. Atriplex subg. Obione subsect. Saccariae] | A. saccaria |
25. Leaf blades never cordate at base or, in some, sessile distal ones sometimes cordate-clasping; fruiting bracteoles all similar on same plant | → 26 |
26. Bracteoles panduriform (fiddle-shaped) in outline (with 2 lateral rounded lobes lateral to terminal tooth), faces often obscured by cristate or unaligned appendages; leaf blades conspicuously 3-veined; Alberta, Saskatchewan, se Oregon, sw Idaho, Oregon, Utah, nw New Mexico, Colorado, Wyoming, South Dakota, Montana [20b.3c. Atriplex subg. Obione subsect. Argenteae, in part] | A. powellii |
26. Bracteoles not panduriform; leaf blades not conspicuously 3-veined | → 27 |
27. Bracteoles broadly rhombic, toothed beyond middle; Sacramento and San Joaquin valleys, California [20.b.3f. Atriplex subg. Obione subsect. Pusillae, in part] | A. cordulata |
27. Bracteoles of various shapes and teeth various; various or other distribution | → 28 |
28. Bracteoles dentate only at truncate apex, small; s British Columbia, Alberta, and sw Saskatchewan, s to California, Nevada, Utah, Colo- rado [20b.3d. Atriplex subg. Obione subsect. Truncatae] | A. truncata |
28. Bracteoles dentate well below apex, often to base, large; other distribution | → 29 |
29. Leaf blades closely repand-dentate; nc to s California, w and s Nevada, Arizona, New Mexico, w and n Texas, and w Oklahoma [20b.3c. Atriplex subg. Obione subsect. Argenteae, in part] | A. argentea |
29. Leaf blades entire or remotely and irregularly dentate; other distribution | → 30 |
30. Leaf blades mostly oblong, oblong-ovate, or elliptic to lanceolate, not subhastate or angled at base; Sacramento and San Joaquin valleys, e and s Coast Ranges, California [20b.3f. Atriplex subg. Obione subsect. Pusillae, in part] | A. coronata |
30. Leaf blades variously shaped, at least some typically subhastate or angled at base, or if acute to obtuse at base (as in some A. argentea varieties) of different distribution; s British Columbia e to sw Manitoba, and s to e Washington, e Idaho, Nevada, se California, Utah, ne Arizona, nw New Mexico, n Texas [20b.3c. Atriplex subg. Obione subsect. Argenteae, in part] | A. argentea |
31. Leaf blades linear, concolorous; bracteoles truncate apically; sw Wyoming, ne and c Utah, n, w, and sc Colorado [20b.3e. Atriplex subg. Obione subsect. Wolfianae] | A. wolfii |
31. Leaf blades usually broader than linear, or if linear, abaxial surface much paler than adaxial and bracteoles not truncate; other distribution | → 32 |
| → 33 |
32. Leaf blades dentate, or if entire staminate glomerules mainly in terminal spikes | → 36 |
33. Bracteole faces, at least some, conspicuously tuberculate or cristate [20b.3g. Atriplex subg. Obione subsect. Arenariae] | → 34 |
33. Bracteole faces typically smooth, sometimes inconspicuously tuberculate | → 35 |
34. Fruiting bracteoles (3.5-)4.5-7 × 3.5-5.6 mm, typically longer than broad, faces with or without appendages; plants coastal from New England s along Atlantic, and along Gulf to Texas | A. mucronata |
34. Fruiting bracteoles 2.5-4.5 × 2.6-5 mm, typically as wide or wider than long, and with faces appendaged; plants coastal from North Carolina s along Atlantic and w along Gulf to coastal or near coastal w Texas | A. pentandra |
35. Staminate glomerules all axillary | A. pacifica |
35. Staminate glomerules mainly in terminal spikes | A. pentandra |
36. Staminate glomerules axillary, or in very short, simple, terminal spikes [20b.3g. Atriplex subg. Obione subsect. Arenariae] | → 37 |
36. Staminate glomerules in elongate, usually paniculate spikes | → 38 |
37. Bracteole faces not appendaged; s California | A. serenana |
37. Bracteole faces tuberculate, muricate, or cristate; coastal se and s United States w to Rio Grande, sw Texas | A. pentandra |
38. Bracteoles 4-6 mm; leaf blades sinuate-dentate; Gulf of St. Lawrence, Prince Edward Island, Nova Scotia, and Quebec [20a.3. Atriplex sect. Sclerocalymma] | A. laciniata |
38. Bracteoles 2-3.5 mm; leaf blades various, but if as above, of different distribution [20b.3g. Atriplex subg. Obione subsect. Arenariae] | → 39 |
39. Leaves lanceolate to oblong, elliptic, or oval, subconcolorous; bracteole faces almost always conspicuously tuberculate; California and w Ne- vada | A. serenana |
39. Leaves linear to lanceolate or oblong, white abaxially, green adaxially; bracteole faces usually unappendaged; s Arizona, s New Mexico and along Rio Grande, in Texas and Mexico | A. wrightii |
1. Leaves sinuate-dentate to dentate or laciniate (at least some), or strongly undulate-crisped and appearing lobed; herbage silvery white | → 2 |
1. Leaves entire or merely hastately lobed, or if sinuate-dentate or denticulate, herbage green or gray | → 3 |
2. Leaf blades deeply, sharply dentate or laciniate; fruiting bracteoles orbiculate, entire to crenate, sessile, surfaces lacking processes; sw Utah, s Nevada, s California | A. hymenelytra |
2. Leaf blades sinuate, sinuate-dentate, or hastate; fruiting bracteoles stipitate, 6-15 mm, macelike, surfaces often with elongate, radiating, hornlike, or flattened processes; se Arizona s New Mexico, along Rio Grande and Gulf Coast, w and s Texas | A. acanthocarpa |
3. Bracteoles conspicuously longitudinally 4-winged, or with tubercles aligned in 4 parallel rows | → 4 |
3. Bracteoles lacking lateral wings (tubercles sometimes aligned in 4 rows) | → 7 |
4. Plants low, seldom more than 4 dm; subshrubs of playas in Great Basin and Range, or w Great Plains | A. gardneri |
4. Plants low or tall; broad or various distribution | → 5 |
5. Leaves mainly 2-3 mm wide and often over 2 cm, narrowly linear-elliptic, often rather acute apically; plants with very slender branchlets; s Arizona and s California | A. linearis |
5. Leaves mostly 3-10+ mm wide, or if occasionally less then often less than 2 cm or of different distribution, or leaves spatulate, thickened, and obtuse apically; plants with branchlets not especially slender; various distribution | → 6 |
6. Leaves mainly 0.3-0.8 cm wide; bract tip lacking lateral teeth; shrubs mainly 8-20 dm; widespread in w North America, from s Canada, southward in United States, mainly w of 100th meridian | A. canescens |
6. Leaves often more than 8 mm wide; bract tip with or without lateral teeth; shrubs mainly 2-8 dm; se Utah and n Arizona | A. garrettii |
7. Plants definitely spiny, branches terminating in thorns; bracteoles foliose, entire, united only at base, surfaces lacking appendages | → 8 |
7. Plants not definitely spiny, or if somewhat so bracteoles at least 1/3 united, surfaces appendaged or not | → 12 |
8. Bracteoles (4-)6-15 mm | → 9 |
| → 10 |
9. Leaves ovate to oval or elliptic, not hastate; body of bracteoles not constricted below free terminal valves; e Montana and sw North Dakota to Oregon, California, Arizona, New Mexico, and Texas | A. confertifolia |
9. Leaves elongate-deltoid and commonly somewhat hastate; body of bracteoles constricted below terminal valves; w San Joaquin Valley and w Mojave Desert, California | A. spinifera |
10. Leaves short petiolate to sessile, cordate basally, blade 0.5-1.5 cm; herbage silvery white; low shrubs | A. parryi |
10. Leaves petiolate, truncate or cuneate basally, typically some subhastate; herbage grayish or greenish; shrubs to 20+ dm | → 11 |
11. Twigs sharply angled, glabrous to sparingly puberulent; sw Utah, Ne- vada, s Arizona, s California | A. torreyi |
11. Twigs terete, commonly puberulent; California, s Nevada, s Utah, and Arizona | A. lentiformis |
12. Leaf blades typically some subhastate (except A. polycarpa, with many, tiny, commonly clustered leaves); shrubs to 30 dm; Utah sw to Mexico | → 13 |
12. Leaf blades attenuate to rounded basally, seldom some subhastate; shrubs mainly less than 20 dm; various distribution | → 15 |
13. Branchlets conspicuously and sharply angled; sw Utah, s Nevada, s Ari- zona, and s California | A. torreyi |
13. Branchlets terete or nearly so; extending to Mexico | → 14 |
14. Leaves 10-50 × 50 mm; sw Utah, Arizona, Nevada, California, Mexico | A. lentiformis |
14. Leaves 3-15 (longer only on juvenile shoots) × 2-4 mm; s Nevada, sw Utah, Arizona, and Mexico from Sonora to Baja California | A. polycarpa |
15. Leaves 2-4+ mm wide; bracteoles with appendages on basal 1/3; staminate flowers in spikes; plants prostrate; w Colorado, ne New Mexico, and e Utah | A. corrugata |
15. Leaves often more than 4 mm wide; bracteoles with appendages various; staminate flowers mainly in panicles; plants not or seldom prostrate; distribution various or other | → 16 |
16. Leaves dentate to denticulate or less commonly some or all entire; bracteoles somewhat rhomboid to orbicular; introduced, native to Australia, known in s California and s Arizona [20a.6 Atriplex sect. Dialysex] | → 17 |
16. Leaves not simultaneously of above size and proportion; fruiting bracteoles various but not as above; w Great Plains and Intermountain region [20c. Atriplex subg. Pterochiton, in part] | → 18 |
17. Leaves elliptic to oblong, often shortly hastate, and sometimes remotely denticulate; bracteoles somewhat rhomboid to semicircular in profile, biconvex, thickened and hard all over or with short papery valves; introduced in coastal s California | A. amnicola |
17. Leaves rhomboid to orbicular, sinuate-dentate; fruiting bracteoles rhomboid to orbicular, papery all over or with thickened base; s California, s Arizona | A. nummularia |
18. Leaves oblong-ovate to orbicular, more than 1 cm wide, proximalmost alternate; stems stiffly erect; staminate glomerules very numerous; se Utah south- ward through e Arizona, New Mexico, w Texas | A. obovata |
18. Leaves linear to oblong, mainly less than 1 cm wide, or if wider, proximalmost opposite; stems prostrate to ascending, or less commonly erect; staminate glomerules numerous; Great Plains w to Great Basin and Colorado River drainage | A. gardneri |
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1. Brown seeds 1.7-3 mm wide; fruiting bracteoles mostly less than 10 mm; leaf blades mainly oblong to lance-oblong or linear, less commonly hastate-lanceolate | var. gmelinii |
1. Brown seeds 2.8-3.5 mm wide; fruiting bracteoles often more than 10 mm; leaf blades oblong to lanceolate or hastate-lanceolate or -ovate | var. alaskensis |
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