Taxonomic studies of North American Sparganium. I. S. hyperboreum and S. minimum

Abstract

The taxonomy of the two similar species Sparganium hyperboreum and S. minimum in North America is investigated by a morphological analysis of herbarium specimens and the construction of hybrid indices. It is concluded that despite some hybridization and apparent introgression the two taxa should be recognized as specifically distinct. The criteria for their separation are presented.

The biogeography of aquatic macrophytes in North America since the Last Glacial Maximum

“… Typha/Sparganium with modern range boundaries for Typha L. (grey fill) from Grace & Harrison (1986), Porsild & Cody (1980), Lewis et al. (1983), Hotchkiss & Dozier (1949), and boundary for Sparganium L. (hatched fill) from Hultén (1968) and Harms (1973). See Fig.…”

Alaska research natural areas: 3. Serpentine slide.

“…Sparganium hyperboreum is known to intergrade with S. minimum (Hartm.) Fries across much of central Alaska, although Harms (1973) considers the two taxa distinct. Many of these aquatic species have propagules that are dispersed by migrating waterfowl; this accounts for the ability of the plants to rapidly colonize ephemeral beaver ponds.…”

Systematics, biogeography, and character evolution of Sparganium (Typhaceae): Diversification of a widespread, aquatic lineage

“…Species identification is made difficult by phenotypic plasticity and confusing taxonomy (Cook and Nicholls, 1986, 1987; Kaul, 1997). Adding to the systematic confusion, hybridization is widely suspected but rarely rigorously verified (Harms, 1973; Cook and Nicholls, 1986, 1987; Les and Philbrick, 1993; Kaul, 1997). Linnaeus (1753) recognized only two species, corresponding broadly to the two growth forms found within the genus: S. erectum (plants emergent) and S. natans (plants floating).…”