Weed Seed: Halogeton glomeratus (Halogeton)

Family

Chenopodiaceae

Common name

Halogeton

Regulation

Prohibited Noxious, Class 1 in the Canadian Weed Seeds Order, 2016 under the Seeds Act. All imported and domestic seed must be free of Prohibited Noxious weed seeds.

Distribution

Canadian: Absent from Canada (Brouillet et al. 2016Footnote 1).

Worldwide: Native to central Asia (CABI 2016Footnote 2). Introduced and widespread in the western half of the United States (USDA-NRCS 2016Footnote 3).

Duration of life cycle

Annual or Winter annual

Seed or fruit type

Utricle, may be in a perianth

Identification features

Size

  • Utricle length: 1.3 - 2.6 mm
  • Utricle width: 1.0 - 1.80 mm
  • Utricle thickness: 1.8 mm
  • Perianth length (without wings): 1.7 - 2.3 mm
  • Perianth width: 1.0 - 1.5 mm

Shape

  • Oval-shaped utricle with a protruding radicle tip; compressed

Surface texture

  • Utricle has a dull surface texture

Colour

  • Utricle is brown-orange, perianth is straw yellow

Other features

  • Tightly coiled embryo can be seen through utricle and seed walls
  • The perianth of some utricles are drawn out into wings at the top of the fruit, 1.5 - 3.0 mm long

Habitat and crop association

Overgrazed rangelands, abandoned farmlands, shrublands, roadsides, railway lines, trails and disturbed areas (CABI 2016Footnote 2).

General information

Halogeton was accidentally introduced into Nevada in 1934, and believed to be initially spread by sheep farming (Blackwell et al. 1979Footnote 4, Pemberton 1986Footnote 5). A prolific seed producer, it can produce more than 100,000 seeds per plant (Pemberton 1986Footnote 5).

Halogeton impedes revegetation due to alteration of soil chemistry, physical structure and the microbial community (Pavek 1992Footnote 6). The high concentration of oxalates in the tissues has caused mass mortalities in sheep (Erickson et al. 1952Footnote 7).

Similar species

Russian thistle (Salsola tragus)

  • Similar fruit shape, both have a coiled embryo visible through the utricle and seed walls.
  • The utricle of Russian thistle is thicker than halogeton which is compressed.
  • Russian thistle utricles have a perianth of a similar shape as halogeton, but the colour is grey and it is funnel-shaped while halogeton is compressed.

Photos

Halogeton (Halogeton glomeratus) utricles and one perianth without wings
Halogeton (Halogeton glomeratus) utricle enclosed in perianth with wings
Halogeton (Halogeton glomeratus) utricle enclosed in perianth without wings, commonly seen
Halogeton (Halogeton glomeratus) utricle
Halogeton (Halogeton glomeratus) seed
Halogeton (Halogeton glomeratus) seed, tightly coiled embryo
Halogeton (Halogeton glomeratus) seed, cross-section (L) and longitudinal section (R)

Similar species

Similar species: Russian thistle (Salsola tragus) utricles, seed, and perianth
Similar species: Russian thistle (Salsola tragus) seed