| Eleocharis palustris (L.) Roem. & Schult. | |
| Publ. & Syn. | Heleocharis intersita Zinserl., Fl. URSS 3: 76, 581 (1935). Type (LE): Belarus: "distr. Rjecziza", 1927, leg. N.M. Savicz 343. |
| Notes | Elven: Two races are generally recognized in Europe and Siberia (e.g., Hylander 1966; Walters 1980; Stace 1997; Elven & al. 2005): subsp. palustris and subsp. vulgaris Walters (Eleocharis vulgaris (Walters) Á. Löve & D. Löve). They have overlapping (parapatric) ranges, differ in several characters, have different chromosome numbers (presumed diploid and tetraploid), and even if some hybrids have been identified, few if any fertile transitional plants are documented. The alternative is as two species. The polymorphic E. palustris s. lat. has been well investigated for morphology and cytology. The major source of European morphological and chromosomal data is Strandhede (1958, 1961, 1965a, 1965b, 1965c, 1965d, 1966, 1967 etc.). For North American chromosomal data, see Harms (1968). Material from the arctic parts of Europe, Siberia, and Alaska belongs to subsp. palustris. Subspecies vulgaris is more southern and western in Europe even if Löve and Löve (1975a) suggested that also this race reaches the Arctic. The situation is different in North America and Greenland. Ball: This group is problematic in arctic Ontario and Manitoba. In general, the diploids are more southern, rarely much farther north than Lake Superior. Most plants from central Ontario northwards have the large fruits and the large scales of the tetraploids, but right on the coast some diploid types reappear. But, there are a few large-fruited plants from Churchill so the northeastern North American tetraploid does just reach the Arctic. But what name should be used for it? Smith et al. (2002) suggested that the name E. palustris var. vigens L.H. Bailey applies to this plant but they did not recognize it formally. Elven: Jørgensen et al. (1958) found the diploid plants in western Greenland to differ morphologically from those in Europe but "match the northernmost specimens of the American H[eleocharis smallii] Britton". Smith et al. (2002) placed E. smallii within E. palustris as one of four informal varieties but as different from var. vigens. We provisionally assign the Greenland plants to subsp. palustris. The coarser Hudson Bay plants are clearly different in several characters from the European subsp. vulgaris (most easily visible in the bracts not being strikingly silvery hyaline). We provisionally enter them under the name var. vigens. |
| Chromosomes | (1) 18 20. - Europe, Far East, Canada, Greenland. - Numerous reports. (2) 36-38. - North America. - Hicks (1929). (3) 50-56 58. - Europe (C), North America. - Hicks (1929, 2n = 50-58 56); Tischler (1934, 2n = 56); Rohweder (1937, 2n = 56). The old reports of numbers different from 2n = 20 are enigmatic as this is an easily recognized species. Jørgensen et al. (1958) discussed and doubted the higher chromosome numbers reported by Hicks (1929) from North America. They were omitted by Löve and Löve (1975a) and not confirmed by Smith et al. (2002). However, as reports of higher numbers seem to come from at least three independent sources they are provisionally included. |
| Geography | Cosmopolitan. |
| Distribution | N = F AN = r AO = ? GW = r Ic = s E = R HL = r YK = r AW = r Tm = r [ key ] |
| Parent taxon | Eleocharis R. Br. |
| Child taxa |
Eleocharis palustris subsp. palustris Eleocharis palustris var. vigens L.H. Bailey |
| PAF ID | 330703 |