Plagiobryoides brachyneura

(Kindberg) J. R. Spence

Phytologia 91: 499. 2009.

EndemicIllustrated
Basionym: Bryum brachyneuron Kindberg Ottawa Naturalist 5: 179. 1892
Treatment appears in FNA Volume 28. Treatment on page 150. Mentioned on page 148.

Plants green or yellow-green. Stems 0.5–2 cm, not julaceous, innovations many; rhizoids many on proximal stem. Leaves crowded, somewhat contorted when dry, erect to erect-spreading when moist, narrowly to broadly ovate, flat or weakly concave, 0.5–2 (–3.5) mm; base not decurrent, red; margins plane or recurved proximally, 1-stratose, limbidium variable, absent on younger leaves to present on older leaves; apex broadly acute; costa not reaching apex to very short-excurrent; proximal laminal cells rectangular, (50–) 60–80 × 18–28 µm, 3–5: 1, sometimes bulging, walls thin; distal cells irregular, 35–50 × 18–25 µm, 1–3: 1, walls incrassate. Specialized asexual reproduction absent. Sexual condition synoicous. Seta thick, (0.5–) 1–1.5 cm, flexuose to sometimes geniculate. Capsule inclined to nutant, 2–4 mm; hypophysis strongly differentiated, elongate; operculum apiculate; peristome reduced; exostome pale-yellow or tan proximally, teeth blunt to lanceolate, irregular, often short; endostome hyaline to pale-yellow, adherent to exostome, segments absent or occasionally a few present, cilia absent. Spores 18–22 µm, papillose, dark yellowbrown.


Phenology: Capsules mature Jul–Aug.
Habitat: Damp to seepy rock faces, crevices
Elevation: low elevations (0-100 m)

Discussion

Plagiobryoides brachyneura is very distinctive, with elongate-necked capsules, very short twisted setae, and short broad distal laminal cells. A. L. Andrews (1935) suggested that P. brachyneura is similar to species of Plagiobryum. The combination of gametophyte and sporophyte characters indicates a relationship with P. cellularis and its allies, thus the species is here transferred to Plagiobryoides. The species should be sought elsewhere in the Bering Sea region, especially in the Aleutian Islands and Siberia; it is known from Saint George, Saint Paul, and Agattu islands.

of conservation concern

Selected References

None.

Lower Taxa

None.

"narrower" is not a number."narrow" is not a number.

John R. Spence +
(Kindberg) J. R. Spence +
reduced +
curved +  and straight +
not decurrent +
Bryum brachyneuron +
cucullate +
not zygomorphic +
inclined +  and nutant +
long-exserted +
elongate-pyriform +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
quadrate +  and long-rectangular +
not differentiated +
appendiculate +
short-excurrent +
subpercurrent +
hexagonal;rhomboidal +
low elevations (0-100 m) +
hyaline;pale-yellow +
tan +  and pale-yellow +
Damp to seepy rock faces, crevices +
polyoicous +, monoicous +, dioicous +  and sexual +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
older +  and younger +
concave +, flat +  and ovate +
larger +  and vegetative +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
differentiated +
quadrate +  and rhomboidal +
short-rectangular +  and quadrate +
not rostrate +  and conic +
lateral +  and terminal +
lateral +  and terminal +
diplolepidous-alternate +
Capsules mature Jul–Aug. +
differentiated +
smooth;papillose +
differentiated +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
flexuose +
geniculate +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Endemic +  and Illustrated +
dark yellowbrown +
germinating +
branched +  and foliate +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Plagiobryoides brachyneura +
Plagiobryoides +
species +
blunt;lanceolate +
distinct +
straight +
specialized +
synoicous +, sexual +  and asexual +
sinuate +
incrassate +
yellow-green +  and green +