910603 Bupleurum americanum J.M. Coult. & Rose
Distribution
West Chukotka: Rare
Wrangel Island: Rare
South Chukotka: Scattered
East Chukotka: Frequent
Western Alaska: Frequent
Northern Alaska - Yukon: Frequent
Central Canada: Rare
Southern Arcti Tundra: Scattered
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent
- J.M. Coult. & Rose, Rev. N. Amer. Umbell.: 115 (1888). Type (WAB): "Alaska", leg. Lay and Collie (see Krasnoborov 1998). - Bupleurum sibiricum Vest in Roem. & Schult., Syst. Veg. 6: 368 (1820) subsp. americanum (J.M. Coult. & Rose) Krasnob., Bot. Zhurn. 83, 2: 125 (1998).
- Bupleurum ranunculoides var. ajanense Regel in Regel & Tiling, Fl. Ajan.: 97 (1858). Type (LE): Russian Far East: "Ajan", 1847, leg. Tiling. - Bupleurum ajanense (Regel) Krasnob. & T. Yamaz., J. Jap. Bot. 70: 341 (1995) subsp. ajanense.
2n=
(1) 14 (2x, x = 7). - Constance et al. (1976).
(2) 22 (2x, x = 11?). - Canada (Yukon). - Bell and Constance (1966).
(3) 28 (4x, x = 7). - Alaska, Canada (W), U.S.A. (W). - Several reports.
The non-arctic North American reports are assigned to this species as it is the only one of the group we accept from these regions. The vouchers of the Alaskan reports of 2n = 28 by Dawe and Murray (1981a, 1981b) have been inspected and belong here.
Geography: Amphi-Beringian: RFE ALA CAN.
Notes: Murray and Elven: In our proposal, Bupleurum americanum is the most widespread Bupleurum in northwestern North America, including both Krasnoborov's B. ajanense subsp. ajanense (at least for the American and Chukotkan areas) and B. sibiricum subsp. americanum. It is characterized by leaves broader, the upper ones distinctly clasping, and bracts and bractlets broad, bractlets overlapping, subacute to obtuse, subequal to or shorter than the umbel rays, and usually pale yellow. The same main features are found in lowland plants (Krasnoborov's B. sibiricum subsp. americanum) and in mountain and tundra plants (Krasnoborov's B. ajanense subsp. ajanense). We do not find Krasnoborov's Cordilleran B. ajanense subsp. purpureum very different either. Its features are frequently found among, e.g., Alaskan plants.
Higher Taxa
- Bupleurum [9106,genus]