Salsola collina |
Salsola |
|||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
slender Russian-thistle, slender saltwort, tumbleweed |
Russian-thistle, salsovie, saltwort, soude, tumbleweed |
|||||||||||||||||||||||||
Habit | Herbs, 10–100 cm, sparsely to densely papillose or hispid (rarely subglabrous). | Herbs, annual, or subshrubs [shrubs and small trees], glabrous, or ± pubescent or hispid. | ||||||||||||||||||||||||
Stems | erect, rarely ascending, branched above base (occasionally with slender branches near base); branches straight or slightly arcuate. |
erect, ascending, or prostrate, branched (rarely simple), not jointed, not armed, not fleshy. |
||||||||||||||||||||||||
Leaves | alternate; blade filiform to narrowly linear, 1–2 mm wide, less than 1 mm wide in herbarium specimens, usually not fleshy, sometimes semi-amplexicaul at base, apex with soft bristle (rarely subspinescent). |
mostly alternate (rarely opposite, especially proximal ones), sessile; blade lanceolate, linear, or filiform to subulate, semiterete, margins entire basally, apex obtuse, soft and subspinescent or narrowed to spine or soft bristle. |
||||||||||||||||||||||||
Inflorescences | not interrupted, dense, 1-flowered (rarely 2–3-flowered), often also in axils of proximal leaves and branches, lower ones tightly enclosed in bracts and bracteoles, forming gall-like caducous balls at maturity; bracts alternate, strongly imbricate and appressed at maturity, base not distinctly swollen, apex acuminate into subulate spine. |
spicate, flowers solitary in axils of bracts or reduced distal leaves (rarely 2–3-flowered with lateral flowers poorly developed); bracts ovate-lanceolate, spine-tipped. |
||||||||||||||||||||||||
Flowers | bracteoles becoming connate basally and adnate to perianth segments; perianth segments wingless or with narrow, erose wing at maturity, apex acute, weak and flaccid, glabrous; fruiting perianth ca. 2–5 mm diam. 2n = 18. |
bisexual, with 2 bracteoles; perianth segments persistent, 5, covering utricle at maturity, often developing transverse, dorsal, membranous or ± coriaceous wing (sometimes only 2–3 segments winged, sometimes wingless or nearly so); stamens 5; styles and stigmas 2 (or 3). |
||||||||||||||||||||||||
Fruits | utricles, covered by perianth segments at maturity; pericarp adherent. |
|||||||||||||||||||||||||
Seeds | usually horizontal, orbicular; seed coat black or brown; perisperm absent. |
|||||||||||||||||||||||||
x | = 9. |
|||||||||||||||||||||||||
Salsola collina |
Salsola |
|||||||||||||||||||||||||
Phenology | Fruiting summer–fall. | |||||||||||||||||||||||||
Habitat | Waste places, roadsides, railway areas, cultivated fields, disturbed natural and seminatural plant communities | |||||||||||||||||||||||||
Elevation | 100-2000 m (300-6600 ft) | |||||||||||||||||||||||||
Distribution |
AZ; CO; IA; KS; KY; MI; MN; MO; MT; ND; NE; NH; NM; NY; OK; SD; UT; VT; ON; SK; Eurasia [Introduced in North America]
|
almost worldwide; Mediterranean region; arid and coastal zones of Eurasia; n Africa; e Africa; s Africa [Introduced in North America] |
||||||||||||||||||||||||
Discussion | Salsola collina was reported for the first time for North America from Minnesota by J. W. Moore (1938). It was collected in Kansas in 1923 (R. E. Brooks et al. 1976), but misidentified. Later it was discovered in Colorado, Iowa, and Missouri (V. L. Cory 1948; W. Schapaugh 1958; V. Muhlenbach 1979). Reports of S. collina for Arizona and New York are based on specimens cited by S. Rilke (1999). Its actual distribution seems to be underestimated due to the common and constant confusion with deviant forms of S. tragus. In the future, S. collina may be expected to occur within the major portion of the present range of S. tragus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species ca. 130 (6 in the flora). In this treatment, a rather broad and traditional generic concept is accepted for Salsola, including Caroxylon and other segregate genera. It is evident that Salsola in the traditional sense should be regarded as a group of genera rather than a natural monophyletic genus. V. I. Pyankov et al. (2001) recently discussed phylogenetic relationships inferred from parsimony analysis of nucleotide sequences of the internal transcribed spacer regions (ITS) of the 18S–26S nuclear ribosomal DNA of 34 species of Salsola and related genera (Halothamnus Jaubert & Spach, Climacoptera Botschantzev, Girgensohnia Bunge, Halocharis Moquin-Tandon, and Haloxylon Bunge) and four species from representative outgroups (tribes Camphorosmeae and Atripliceae). The study confirmed that Salsola sensu lato is polyphyletic, with several currently recognized related genera rooted within the group. Results of the V. I. Pyankov et al. study also contradict V. P. Botschantzev’s (1969) hypothesis of a South African origin of Salsola sensu lato and place the “cradle” of the genus in central Asia. A comparative taxonomic and phytogeographic analysis (S. L. Mosyakin 2002) also suggests the place of origin of the Salsola generic aggregate is somewhere in the Tethyan region of south-central Asia (probably northern coasts of the ancient Tethys, or adjacent inland lacustrine habitats). Almost all North American taxa belong to Salsola sensu stricto. Species of Salsola sect. Caroxylon (Thunberg) Fenzl, which is represented in North America only by the introduced S. vermiculata, may be recognized in the distinct genus Caroxylon Thunberg following a comprehensive study of the group worldwide. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||||||||||
Key |
|
|||||||||||||||||||||||||
Source | FNA vol. 4, p. 402. | FNA vol. 4. | ||||||||||||||||||||||||
Parent taxa | Chenopodiaceae > Salsola | Chenopodiaceae | ||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||
Name authority | Pallas: Ill. Pl., 34. (1803) | Linnaeus: Sp. Pl. 1: 222. (1753): Gen. Pl. ed. 5, 104. (1754) | ||||||||||||||||||||||||
Web links |
|