Halogeton glomeratus
in C. F. von Ledebour, Icon. Pl. 1: 10. 1829.
Stems: main terminal stem erect, lateral 4 decumbent to spreading from base, 1–4 dm, the 5 stems becoming much branched in vigorous plants. Leaf blades linear, 4–14(–17) mm. Inflorescence: each axillary group typically 3 glomerulate with, 2 lateral bracteate, (1–)2–3-flowered glomerules and a pistillate, 1-flowered, ebracteate one between. Perianth 5-parted from near base, well developed in bisexual flowers, segments differentiated into 2–3 mm claw and 2–4 mm-wide blade; blade flabelliform, firm, transparent-membranous; segments of central flower developing earlier than lateral ones, without blade; stamens 3–5; filaments connate into 2 clusters of 2 or 3. Utricles vertical, dimorphic, associated with 2 types of flowers, lateral ones blackish, 0.5–1 mm, central one brown, 1–2 mm. 2n = 18.
Phenology: Flowering Jul–Aug; fruiting fall.
Habitat: Disturbed, barren, alkaline soils
Elevation: 1200-2100 m
Distribution
Introduced; Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo., native to Eurasia.
Discussion
A noxious and toxic weed in disturbed, barren, alkaline soils, Halogeton glomeratus is able to withstand high concentrations of salinity. It is often associated with Sarcobatus vermiculatus and Atriplex confertifolia and is found in the cold deserts of western United States.
The first collection of Halogeton in the United States was by Ben Stahmann in Wells, Nevada, in 1934. It was not until the fall of 1942, when a herder lost 160 sheep, that the species was recognized as toxic to livestock (J. A. Young et al. 1999).
Selected References
None.