Page author: Ben Legler
Diphasiastrum alpinum × Diphasiastrum sitchense
hybrid clubmoss
A typical intermediate plant, with 4-ranked green leaves that show a hint of the shape of L. alpinum but without the dimorphism present in that parent.
This hybrid more closely resembles L. alpinum with its strongly 4-ranked and somewhat dimorphic leaves, except the stems are green, and the ventral stem leaves are not trowel-shaped.
Except for the strongly 4-ranked leaves, this hybrid closely resembles L. sitchense.
WTU specimens
Other herbaria

Distribution: Known from British Columbia south to Oregon and east to Montana, also in Greenland and Newfoundland.

Habitat: Upper montane coniferous forest and brushy areas, and subalpine and alpine meadows. In Washington, has been found in subalpine-alpine heath meadows and on shaded mossy mineral soil below conifers on high montane roadcuts.

Origin: Native

Conservation Status: Not of concern

Description:
General:

Perennial herb, forming dense low mats with creeping horizontal stems and short, branched, erect stems to 15 cm tall; stems and leaves ranging from blue-green to yellow-green.

Leaves:

Small and scale- or needle-like. Shape and arrangement varies between that of either parent, from needle-like and spirally arranged (as in L. sitchense) to scale-like, 4-ranked, and slightly dimorphic (as in L. alpinum). Typical intermediate plants have mostly 4-ranked leaves that are shortly needle-like with some slightly dimorphic and a slight blue-green cast.

Spores:

Contained in stroboli (spore cones) that are solitary at stem tips, light green to tawny, 5-40 mm long.

Identification Notes:

Difficult to separate from either parent, and can show a range of features from that of one parent to that of the other. Some plants closely resemble L. sitchense except for having strongly 4-ranked leaves that are often shorter and more scale-like than is normal in this parent. However, true L. sitchense sometimes will have partially 4-ranked leaves. Other plants may closely resemble L. alpinum with strongly 4-ranked, blue-green, and more scale-like leaves, but the characteristic trowel-shaped ventral leaves of true L. alpinum will be absent.

Comments:

Often found growing in immediate proximity to both parents, in which case the hybrids are most easily recognized. However, has on occasion been found growing only with L. sitchense. Additional collections of this hybrid should be sought in Washington.

Accepted Name:
Diphasiastrum alpinum (L.) Holub × Diphasiastrum sitchense (Rupr.) Holub

Synonyms & Misapplications:
Lycopodium alpinum L. × Lycopodium sitchense Rupr.
Additional Resources:

PNW Herbaria: Specimen records of Diphasiastrum alpinum × Diphasiastrum sitchense in the Consortium of Pacific Northwest Herbaria database.

WA Flora Checklist: Diphasiastrum alpinum × Diphasiastrum sitchense checklist entry.

E-Flora BC: Diphasiastrum alpinum × Diphasiastrum sitchense atlas page.

CalPhotos: Diphasiastrum alpinum × Diphasiastrum sitchense photos.

USDA Plants: Diphasiastrum alpinum × Diphasiastrum sitchense information.

14 photographs:
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