Arctoa hyperborea

(Gunnerus ex Withering) Bruch & Schimper
Bryol. Europ. 1: 157. 1846,.
Basionym: Bryum hyperboreum Gunnerus ex Withering
Synonyms: Cynodontium hyperboreum (Gunnerus ex Withering) Hagen Dicranum hyperboreum (Gunnerus ex Withering) Smith
Treatment appears in FNA Volume 27. Treatment on page 363. Mentioned on page 362.
Revision as of 17:55, 18 September 2019 by FNA>Volume Importer

Plants in compact, dark green tufts. Stems 1–3(–5) cm. Leaves erect-spreading, lanceolate, subulate, 2–3 mm; costa 30–55 µm wide at base, short-excurrent, rough near tip; distal laminal cells mostly subquadrate (1–2:1), incrassate; basal laminal cells elongate, alar cells differentiated, quadrate or slightly enlarged. Seta 4–6(–8) mm. Capsule exserted, slightly curved, obscurely to distinctly ribbed when dry, annulus developed, separating; peristome large, not spreading outward when dry. Spores 18–30 µm.

Phenology: Capsules mature summer.
Habitat: Siliceous rock or soil
Elevation: high-alpine elevations


Arctoa hyperborea is a rare arctic-alpine moss found on rock ledges or crevices at high elevations. It is distinguished from other species of the genus by its short-excurrent costa, shorter seta (the length is highly variable), and peristome not spreading when dry.

Selected References


Lower Taxa


... more about "Arctoa hyperborea"
Steven G. Newmaster +
(Gunnerus ex Withering) Bruch & Schimper +
Bryum hyperboreum +
Greenland +  and Europe. +
high-alpine elevations +
Siliceous rock or soil +
Capsules mature summer. +
Bryol. Europ. +
Cynodontium hyperboreum +  and Dicranum hyperboreum +
Arctoa hyperborea +
species +