Atriplex saccaria var. asterocarpa

(Stutz

Rhodora 102: 420. 2001.

Common names: Starbract orach
Endemic
Basionym: Atriplex asterocarpa Stutz G. L. Chu & S. C. Sanderson, Madroño 41: 199, fi gs. 1, 2. 1994
Treatment appears in FNA Volume 4. Treatment on page 349. Mentioned on page 348.

Herbs, annual, 1.5–3 dm. Stems erect, branching from base to top, terete, scurfy above. Leaves: petiole 2–10 mm; blade oval to narrowly so, 6–15(–25) × 5–10(–15) mm, base truncate to rounded or rather abruptly cuneate, margin entire, apex acute to rounded. Staminate flowers in glomerules arranged in spikes 1–3 cm at branch apices. Fruiting bracteoles always (?) monomorphic, usually on stipes 2–6 mm, body 5–6 mm thick, globose, with thickened, hard, hornlike appendages.


Phenology: Flowering Apr–Sep.
Habitat: Fine-textured, saline (frequently semibarren) substrates of the Chinle and Entrada formations, with Atriplex confertifolia, Phacelia crenulata, and Eriogonum inflatum
Elevation: 1100-1400 m

Discussion

This taxon is allied to both Atriplex saccaria and A. cornuta but distinguished mainly by the fruiting bracteoles profusely covered with hard, thickened processes. Evidently absent in specimens of var. asterocarpa are the small, cuneate, truncate, smooth bracteoles typical of A. saccaria, but in some specimens the juvenile fruiting bracteoles suggest such a condition, which is noted both in var. saccaria proper and in var. cornuta. The overall aspect of var. asterocarpa is, despite lacking this one feature, that of A. saccaria. This is apparently the basis of my earlier interpretation of A. caput-medusae within A. saccaria.

Selected References

None.

Lower Taxa

None.
Stanley L. Welsh +
(Stutz +
Atriplex asterocarpa +
Starbract orach +
Ariz. +  and Utah. +
1100-1400 m +
Fine-textured, saline (frequently semibarren) substrates of the Chinle and Entrada formations, with Atriplex confertifolia, Phacelia crenulata, and Eriogonum inflatum +
Flowering Apr–Sep. +
Atriplex truncata var. saccaria +  and Obione saccaria +
Atriplex saccaria var. asterocarpa +
Atriplex saccaria +
variety +