Arctoa hyperborea

(Gunnerus ex Withering) Bruch & Schimper

Bryol. Europ. 1: 157. 1846,.

Basionym: Bryum hyperboreum Gunnerus ex Withering Syst. Arr. Brit. Pl. ed. 4, 3: 811. 1801
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.

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

Discussion

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

None.

Lower Taxa

None.
... more about "Arctoa hyperborea"
persistent +  and deciduous +
Steven G. Newmaster +
(Gunnerus ex Withering) Bruch & Schimper +
short to long +
Bryum hyperboreum +
pseudomonoicous +, dioicous +, autoicous +  and sexual +
reproduction +  and asexual +
cucullate +
constricted +
papillose +  and mammillose +
quadrate +
enlarged +
differentiated +
short-excurrent +
30um;55um +
mammillose +  and smooth +
Greenland +  and Europe +
high-alpine elevations +
Siliceous rock or soil +
falcate-secund +
subulate +  and lanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
serrulate +  and entire +
nonpitted +  and pitted +
toothed +  and forked +
autoicous +  and sexual +
pitted-striolate +
Capsules mature summer. +
undifferentiated +
Bryol. Europ. +
0.6 cm6 mm <br />0.006 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
flexuose +  and straight +
cygneous +  and elongate +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
spheric +
simple or;dichotomously irregularly branched +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
differentiated +
superficial +
Cynodontium hyperboreum +  and Dicranum hyperboreum +
Arctoa hyperborea +
species +
deciduous +
lanceolate +
dark green +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
dark green +  and yellowish-brown +