Cassiope lycopodioides

Clubmoss mountain-heather
Cassiope lycopodioides on Mount Chōkai, Yamagata Prefecture, Japan
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Ericales
Family:	Ericaceae
Genus:	Cassiope
Species:	C. lycopodioides
Binomial name
Cassiope lycopodioides (Pall.) D. Don
Synonyms [1] [2]
Andromeda lycopodioidesPall. Cassiope lycopodioides var. cristapilosa(Calder & R.L.Taylor) B.Boivin Cassiope lycopodioides subsp. cristapilosaCalder & Roy L.Taylor Erica lycopodioidesWaitz Ericoides lycopodiodes(Waitz) Kuntze

Cassiope lycopodioides is a plant species in the family Ericaceae, known by the common names clubmoss mountain-heather or Haida Gwaii mountain-heather. The species is native to northeast Asia and northwestern North America, where it grows on rocky slopes and crevices in arctic tundra and alpine tundra at elevations up to 2000 m. ^[3] .

Description

Cassiope lycopodioides is a perennial herb forming mats lying close to the ground. Leaves are narrow, up to 3 mm long, closely pressed against the stem. Curled hairs are present at the leaf tips, especially on younger leaves, and most populations (with the exception of those on Haida Gwaii) display hyaline or scarious leaf margins. Flowers are white, campanulate (bell-shaped), up to 20 mm across, and with a calyx of five fused sepals, often red or reddish green. ^{[3] [4] [5] [6] [7] [8]}

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  Cassiope lycopodioides on Mount Yake, Hida Mountains, Takayama, Gifu Prefecture, Japan
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  Cassiope lycopodioides on Mount Chōkai, Yamagata Prefecture, Japan
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  Closeup of leaves. Mount Yake, Hida Mountains, Takayama, Gifu Prefecture, Japan
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  Cassiope lycopodioides in habitat, with Schizocodon soldanelloides var. soldanelloides f. alpinus in the bottom left corner. Mount Yake, Hida Mountains, Takayama, Gifu Prefecture, Japan

Distribution

The distribution of Cassiope lycopodioides spans an arc of the northern Pacific Rim, extending from northeast Asia over to northwestern North America. In Asia, the species ranges from high elevations on Honshu and Hokkaido in Japan ^[9] , north through coastal mountain ranges and tundra of the Russian Far East. ^[10]

In North America, the species is found across the Aleutian Islands into southern Alaska, coastal and interior British Columbia, and the U.S. State of Washington. ^[3] Washington populations have been reported only from shaded alpine rock faces in King County and Snohomish County. ^[11]

The specific epithet "lycopodioides" refers to the plant's superficial resemblance to some species of clubmoss (Lycopodium sensu lato).

Cultivated specimen, cultivar 'Beatrice Lilley'

Taxonomy

Cassiope lycopodioides subsp. cristapilosa, known only from the Haida Gwaii (formerly called the Queen Charlotte Islands), is recognized as a distinct taxon by some authorities ^{[2] [12]} but not others. The distinction is based on morphological differences between Haida Gwaii plants and other populations, such as the lack of a hyaline margin to the leaf, and longer pedicels and corollas. ^[3]

Phylogenetic studies of Japan populations revealed genetic divergence between populations from central Honshu and populations from northern Honshu into Hokkaido; these are theorized to be two distinct colonizations of the species during different glaciation events during the Pleistocene, following a biogeographical pattern reflected by other alpine plant species in the archipelago. ^[13]

References

1. Tropicos
2. The Plant List
3. Flora of North America v 8 p 448
4. Boivin, Joseph Robert Bernard. 1966. Le Naturaliste Canadien 93(4): 433.
5. Don, David. 1834. Edinburgh New Philosophical Journal 17(33): 158.
6. Pallas, Pyotr Simon von. 1788. Flora Rossica 1(2): 55, pl. 73, f. 1.
7. Welsh, S. L. 1974. Anderson's Flora of Alaska and Adjacent Parts of Canada i–xvi, 1–724. Brigham Young University Press, Provo.
8. Scoggan, H. J. 1979. Dicotyledoneae (Loasaceae to Compositae). Part 4. 1117–1711 pp. In Flora of Canada. National Museums of Canada, Ottawa.
9. Specimen records, U.S. National Arboretum Herbarium
10. Consortium of Pacific Northwest Herbaria
11. Cassiope lycopodioides - Burke Herbarium Image Collection
12. Calder, James Alexander & Taylor, Roy Lewis. 1965. Canadian Journal of Botany 43(11): 1397–1398.
13. Ikeda, H. Decades-long phylogeographic issues: complex historical processes and ecological factors on genetic structure of alpine plants in the Japanese Archipelago. J Plant Res 135, 191–201 (2022).