Agoseris glauca var. dasycephala

(Torrey & A. Gray) Jepson

Man. Fl. Pl. Calif., 1005. 1925

Common names: Arctic agoseris
Synonyms: Agoseris altissima RydbergAgoseris aspera (Rydberg) RydbergAgoseris eisenhoweri B. BoivinAgoseris glauca subsp. aspera (Rydberg) PiperAgoseris glauca var. aspera (Rydberg) CronquistAgoseris glauca var. pumila (Nuttall) GarrettAgoseris glauca subsp. scorzonerifolia (Schrader) PiperAgoseris glauca var. villosa (Rydberg) G. L. WittrockAgoseris isomeris (Nuttall) RydbergAgoseris lanulosa (Schrader) GreeneAgoseris leontodon var. aspera RydbergAgoseris leontodon var. pygmaea RydbergAgoseris maculata RydbergAgoseris pubescens unknownAgoseris pumila unknownAgoseris scorzonerifolia unknownAgoseris turbinata unknownAgoseris vestita unknownAgoseris villosa unknown
Basionyms: Troximon glaucum var. dasycephalum Torrey & A. Gray
Treatment appears in FNA Volume 19. Treatment on page 326. Mentioned on page 327, 328, 329, 334.
Click plate for higher resolution version.
Leaf blades: margins often undulate, usually entire, sometimes lobed, faces usually puberulent to densely villous, sometimes glabrous, rarely glaucous. Peduncles usually apically villous to lanate (glabrous in one phase), sometimes ± stipitate-glandular. Involucres obconic to hemispheric. Phyllaries often medially rosy purple and usually with some combination of purple-black spots, speckles, midstripes, or tips, rarely all green, margins ± undulate or reflexed, often hairy, faces usually villous to hirsuto-tomentose, sometimes glabrous, mostly stipitate-glandular; outer erect or spreading, usually adaxially villous, sometimes glabrous. Receptacles usually ± paleate. Cypselae usually glabrous, sometimes scabrous distally. 2n = 36.

Phenology: Flowering Jul–Aug.
Habitat: Moist to dry habitats, alpine meadows, montane forests, northern prairies, arctic tundra, in gravelly, rocky, and other coarse-textured soils
Elevation: 100–3600 m

Distribution

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Alta., B.C., Man., N.W.T., Sask., Yukon, Colo., Idaho, Mont., N.Dak., Oreg., S.Dak., Utah, Wash., Wyo.

Discussion

Variety dasycephala occurs primarily at high elevations in the western cordillera, extending eastward onto the northern prairies, and disjunctively in the Canadian arctic (Caribou Hills). It is more readily distinguished from var. glauca southward, where the two varieties are ± elevationally separated. Difficulty in separating them occurs northward, where they are nearer each other and pockets of complete introgression occur, e.g., southeastern British Columbia and southwestern Alberta. Hybrids with Agoseris aurantiaca and A. parviflora also occur.

Variety dasycephala contains regional phases that exhibit a step-clinal distribution. The large number of synonyms reflects the variation. As circumscribed here, var. dasycephala encompasses most of what has been called Agoseris glauca var. agrestis (see discussion under var. glauca).

References

None.

Lower Taxa

No lower taxa listed.