Atriplex gardneri var. aptera

(A. Nelson) S. L. Welsh & Crompton

Great Basin Naturalist 55: 326. 1995.

Common names: Nelson’s saltbush
Endemic
Basionym: Atriplex aptera A. Nelson Bot. Gaz. 34: 356. 1902
Synonyms: Atriplex canescens subsp. aptera (A. Nelson) H. M. Hall & Clements
Treatment appears in FNA Volume 4. Treatment on page 374. Mentioned on page 372.

Subshrubs, dioecious or sparingly monoecious, mainly 2–5 dm. Stems mainly from a basal crown. Leaves deciduous or tardily so, alternate or proximal ones opposite, sessile or subsessile; blade green to yellow-green, oblanceolate to elliptic or spatulate, 15–40 × 6–12 mm, 2–6 times longer than wide. Staminate flowers yellow, in glomerules 3 mm thick, in terminal or axillary spikes or spicate panicles to 12 cm. Pistillate flowers in spicate panicles 8–25 cm. Fruiting bracteoles sessile or on stipes to 5 mm, body basically ellipsoid, bearing 4 deeply lobed lateral wings or rows of flattened tubercles to 4 mm high, 4–8 mm and as wide, apex 1.5 mm, with 2–4 lateral smaller teeth, wings, sometimes vestigial, rarely absent. 2n = 36.


Phenology: Flowering summer–fall.
Habitat: Saline, often moist, fine-textured substrates
Elevation: 400-1100 m

Distribution

V4 738-distribution-map.gif

Alta., Sask., Mont., Nebr., N.Dak., S.Dak., Wyo.

Discussion

Atriplex gardneri var. aptera is a Great Plains-Steppe endemic.

The concept of Atriplex aptera is based on recurring and at least partially stabilized introgressant populations derived through hybridization between A. gardneri and A. canescens. Hence, the plants do not form a traditionally conceived taxon in the sense of being monophyletic. They are, however, of frequent occurrence, evidently fertile and long lived, and are taxon-like in distribution. While intermediate in many ways, they are habitually most similar to A. gardneri but bear yellow staminate flowers and the fruiting bracteoles are either winged as in A. canescens or the tubercles are aligned in four rows. They tend to occupy similar saline habitats as those occupied by A. gardneri. Despite the origin of the A. aptera material, and regardless of its local abundance, it does not appear to overwhelm either of the parental species. Staminate specimens of A. aptera are difficult, if not impossible, to distinguish from A. gardneri var. gardneri or A. canescens.

Selected References

None.

Lower Taxa

None.
wingless +  and winged +
toothed +, retuse +  and obtuse or rounded +
1.5 cm15 mm <br />0.015 m <br /> (?) +
Stanley L. Welsh +
(A. Nelson) S. L. Welsh & Crompton +
slippery +
aromatic +
cuneate +
Atriplex aptera +
green;yellow-green +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
oblanceolate +  and elliptic or spatulate +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
ellipsoid +
persistent +  and deciduous +
reddish-brown +, black +, brown +  and green +
3-5-parted +
Nelson’s saltbush +
Alta. +, Sask. +, Mont. +, Nebr. +, N.Dak. +, S.Dak. +  and Wyo. +
400-1100 m +
pistillate +  and staminate +
unisexual +  and bisexual +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
not +  and connate +
enlarged +
Saline, often moist, fine-textured substrates +
bladderlike +
terminal +  and axillary +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
sessile +  and petiolate +
tardily +  and deciduous +
not winged +  and winged +
toothed +  and lobed +
stipitate +  and sessile +
inferior +, half-inferior +  and superior +
crassinucellate +  and bitegmic +
campylotropous +
1 +  and single +
8 cm80 mm <br />0.08 m <br /> (25 cm250 mm <br />0.25 m <br />) +
persistent +  and deciduous +
(1-)3-5-lobed +
papery +  and chartaceous +
Flowering summer–fall. +
subsessile +  and sessile +
Great Basin Naturalist +
pointing +  and ascending +
sublateral +  and superior +
bulbous +  and taprooted +
fusiform +
fleshy +  and fibrous +
verrucate +  and striate +
brown +  and tan +
flattened +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
cylindric +
3 +  and 5 +
opposite +  and alternate +
erect +, prostrate +  and ascending +
succulent +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
sessile +  and petiolate +
reduced;small +
horizontal +  and vertical +
verrucate +
Atriplex canescens subsp. aptera +
Atriplex gardneri var. aptera +
Atriplex gardneri +
variety +
spicate +  and naked +
spicate +  and naked +
tuberculate +
flattened +
dicotyledonous +
perennial +  and annual +
monoecious +  and dioecious +