240205 Stuckenia subretusa (Hagstr.) Holub
Distribution
Kanin - Pechora: Rare
Taimyr - Severnaya Zemlya: Rare
Yana - Kolyma: Rare
West Chukotka: Rare
South Chukotka: Rare
Western Alaska: Scattered
Northern Alaska - Yukon: Scattered
Central Canada: Rare
Shrub Tundra: Scattered
Bordering boreal or alpine areas: Frequent
- Holub, Preslia 68: 364 (1997). - Potamogeton subretusus Hagstr., Kongl. Svenska Vetenskapsakad. Handl., n. s., 55, 5: 30 (1916). Described from the Nikandrovsk and Malobrekhovsk islands near Dudinka at the lower Jenisei River (Siberia).
Geography: Asian (N) - amphi-Beringan: RUS SIB RFE ALA CAN.
Notes: We are not fully convinced that Stuckenia retusa is a taxon. Stuckenia subretusa is distinguished from S. filiformis by many leaves with a small notch at the tip vs. blunt to acute and never with a notch, and in addition by having 6-8 whorls of flowers vs. 3-5 (Tolmachev 1960). Whether the notch character is as important as stated by Tolmachev (1960: 84; translated in Tolmachev et al. 1995: 76) remains to be confirmed. Tzvelev (PAF proposal) reported S. subretusa from western Alaska but Haynes and Hellquist (2000c) did not assign any North American plant under this name. However, numerous Alaskan plants of Stuckenia have a distinct notch, and it is even emphasized in the key and description of Haynes and Hellquist as a character separating S. filiformis (and S. vaginata) from S. pectinata. A similar notch has not been observed yet in European material we have inspected of S. filiformis and S. vaginata. We accept the presence of S. subretusa in the Russian meaning in Alaska and also in Canada where it has been collected at least in Victoria Island (CAN). However, we are not sure the characters used are sufficient to justify a species. The alternative is that this character varies within S. filiformis.
Higher Taxa
- Stuckenia [2402,genus]