Ptychostomum knowltonii

(Barnes) J. R. Spence

Phytologia 87: 21. 2005.

Basionym: Bryum knowltonii Barnes Bot. Gaz. 14: 44. 1889 (as knowltoni)
Treatment appears in FNA Volume 28. Treatment on page 160. Mentioned on page 157, 161.

Plants in dense turfs, green or yellow-green. Stems 0.5–2 (–3) cm, evenly foliate to comose, innovations elongate and evenly foliate; weakly radiculose. Leaves green, somewhat imbricate to weakly contorted or shrunken when dry, ovate, strongly concave, 1–2 (–3) mm, somewhat enlarged toward stem apex; base not decurrent; margins revolute to mid leaf, limbidium strong, in (2–) 3–4 (–5) rows; apex acute to obtuse; costa percurrent to short-excurrent, awn recurved, denticulate; proximal laminal cells 3–4: 1, same width as more distal cells; medial and distal cells hexagonal, 14–18 µm wide, (2–) 3–4: 1, walls thin. Specialized asexual reproduction absent. Sexual condition synoicous. Seta (2–) 3–4 cm. Capsule yellowbrown, obovate to short-pyriform, symmetric, 2–3 mm, mouth red; operculum short-convex, apiculate; peristome reduced; exostome teeth yellow to orange proximally, hyaline distally, lamellae straight mid-tooth, pores absent along mid line; endostome not adherent to exostome, basal membrane high, less than 1/2 exostome height, segments with ovate perforations, cilia absent or rudimentary. Spores (18–) 20–30 µm, finely papillose, pale-yellow or green.


Phenology: Capsules mature Jul–Aug.
Habitat: Wet soil in arctic-alpine
Elevation: low to high elevations (0-4000 m)

Distribution

V28 254-distribution-map.gif

Greenland, Alta., B.C., Nfld. and Labr., N.W.T., Nunavut, Yukon, Alaska, Colo., Wyo., Eurasia

Discussion

Ptychostomum knowltonii is a distinctive species of small, evenly foliate plants with concave, ovate, keeled leaves, and a short capsule on a long, slender seta. The costae are red and prominent abaxially. In some collections, the capsules are of distinctly different ages in the same tufts.

Selected References

None.

Lower Taxa

None.

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

... more about "Ptychostomum knowltonii"
acute;obtuse +
John R. Spence +
(Barnes) J. R. Spence +
denticulate +
reduced +
curved +  and straight +
not decurrent +
Bryum knowltonii +
cucullate +
0.6 cm6 mm <br />0.006 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
nutant +, inclined +  and suberect +
long-exserted +
obovate +  and short-pyriform +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
inflated +
not differentiated +
appendiculate +
rudimentary +
percurrent +  and short-excurrent +
subpercurrent +
rhomboidal;hexagonal +
Greenland +, Alta. +, B.C. +, Nfld. and Labr. +, N.W.T. +, Nunavut +, Yukon +, Alaska +, Colo. +, Wyo. +  and Eurasia +
low to high elevations (0-4000 m) +
hyaline;pale-yellow +
not adherent +
hyaline +, brown +, orange +  and yellow +
hyaline +, yellow +  and orange proximally +
Wet soil in arctic-alpine +
not +  and differentiated +
narrowly ovatelanceolate;triangular +
polyoicous +, monoicous +, dioicous +  and sexual +
imbricate;weakly contorted +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
erect;erect-spreading +
concave +  and ovate +
enlarged +  and shrunken +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2-stratose +  and 1-stratose +
revolute entire +  and denticulate +
1 (?) +, 3 (?) +  and 4 (?) +
short-rectangular +  and quadrate +
short-convex +
lateral +  and terminal +
lateral +  and terminal +
diplolepidous-alternate +
Capsules mature Jul–Aug. +
differentiated +
smooth;papillose +
not absent +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
straight +  and flexuose +
elongate +
3 cm30 mm <br />0.03 m <br /> (4 cm40 mm <br />0.04 m <br />) +
green +  and pale-yellow +
germinating +
variable +
2 cm20 mm <br />0.02 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
Ptychostomum knowltonii +
Ptychostomum subg. Cladodium +
species +
lanceolate +
distinct +
not +  and porose +
straight +
specialized +
synoicous +, sexual +  and asexual +
sinuate +
incrassate +
yellow-green +  and green +
large;small to very +