Rhizomnium nudum |
Rhizomnium glabrescens |
|
---|---|---|
naked rhizomnium moss |
fan moss, large leafy moss, rhizomnium moss |
|
Habit | Plants (1–)2–5 cm. | Plants (1–)2–3 cm. |
Stems | dark red or reddish brown when old; micronemata absent. |
reddish brown, brown, or black when old; micronemata absent. |
Leaves | green to dark green, weakly contorted when dry, broadly obovate, elliptic, or often ± orbicular, (3.8–)4–6(–9) mm; margins green or sometimes pale reddish, 1–4-stratose; apex rounded, occasionally retuse, rarely short-apiculate; costa ending well before apex to 7/8 leaf length or rarely subpercurrent; medial laminal cells elongate or short-elongate, (60–)70–130(–170) µm, rarely collenchymatous, walls with broad central pits; marginal cells linear or short-linear, in (1–)2(–3) rows. |
green to dark green, slightly contorted and somewhat undulate when dry, obovate or elliptic, (2.5–)4.5–6 mm; margins green or sometimes reddish or brownish, 2–4-stratose; apex rounded or occasionally obtuse or retuse, short-apiculate; costa subpercurrent or percurrent; medial laminal cells short-elongate, sometimes elongate or ± isodiametric, (35–)45–60(–70) µm, weakly or not collenchymatous, walls pitted; marginal cells linear, in 3–4(–5) rows. |
Seta | 1–2.5 cm. |
(2–)3–5 cm. |
Sexual condition | dioicous. |
dioicous. |
Capsule | ovate, 2.5–3.5 mm; operculum conic-apiculate; exostome yellow, lamellae 18+. |
oblong or cylindric, 3–4.5 mm; operculum conic-apiculate or conic-rostrate; exostome greenish yellow, lamellae 18+. |
Spores | 25–35 µm. |
30–45 µm. |
Rhizomnium nudum |
Rhizomnium glabrescens |
|
Phenology | Capsules mature spring. | Capsules mature summer. |
Habitat | Forests along streams, marshes, swamps on moist soil, humus, rock | Forests, logs or tree bases, moist soil near streams, thin soil over shaded rock |
Elevation | low to moderate elevations | low to moderate elevations |
Distribution |
AK; ID; MT; OR; WA; AB; BC; Asia
|
AK; CA; ID; OR; WA; BC
|
Discussion | Rhizomnium nudum is one of the most easily recognized species of the genus. The plants are characterized by the absence of micronemata, by their broad, weakly contorted, and nearly flat leaves when dry, and by having thin central laminal cell walls (broad pits), the bar bell appearance of the walls observed in leaf sections. The leaves are only weakly undulate when moist. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Rhizomnium glabrescens, common in coastal forests along the west coast, is small but distinctive. Male plants are characterized by rosettes of large leaves at the tops of the nearly naked stems. Small, scalelike leaves are present along the stem below the upper rosette. The stems of female and sterile stems have relatively large leaves. Sterile stems often arch, resembling those of Plagiomnium, but are always the same length or shorter than the fertile stems. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 28, p. 241. | FNA vol. 28, p. 239. |
Parent taxa | Mniaceae > Rhizomnium | Mniaceae > Rhizomnium |
Sibling taxa | ||
Synonyms | Mnium nudum | Mnium glabrescens |
Name authority | (R. S. Williams) T. J. Koponen: Ann. Bot. Fenn. 5: 143. (1968) | (Kindberg) T. J. Koponen: Ann. Bot. Fenn. 5: 143. (1968) |
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