Phytoneuron 2013-3: 1. 2013.
Plants in dense or open turfs, olive green, red-green, or yellow-green. Stems 4–8 (–12) cm, tufted, comose, innovations elongate and evenly foliate; weakly radiculose. Leaves yellow-green to green, proximal leaves distinctly black-gray with age, distant, strongly twisted to contorted when dry, ovate, concave, (1–) 2–3 mm, not much enlarged toward stem apex; base narrow, weakly decurrent; margins revolute to mid leaf or beyond, limbidium strong, in 2 or 3 rows; apex broadly acute to obtuse; costa not reaching apex to percurrent, awn absent; proximal laminal cells 3: 1, same width or wider than more distal cells; medial and distal cells rhomboidal, 15–20 µm wide, 2–3: 1, walls thin. Specialized asexual reproduction absent. Sexual condition dioicous. Sporophytes unknown.
Habitat: Wet soil, bogs, wetlands
Elevation: low to moderate elevations (0-800 m)
Greenland, Alta., N.W.T., Ont., Yukon, n Eurasia
Ptychostomum subneodamense is a distinctive species that can only be confused with P. cyclophyllum and P. neodamense. Diagnostic characters include very distant, strongly shrunken leaves when dry, a rather narrow reddish leaf base, and 1-stratose border. When leaves are stripped off the stem, a long strip of the stem often remains attached to the leaf base. Ptychostomum cyclophyllum has broadly ovate to orbicular green leaves with very long proximal laminal cells, base not red, and 2-stratose margins; whereas P. neodamense has much more crowded leaves with a fairly broad attachment to the stem, but is otherwise similar.
"narrower" is not a number."narrow" is not a number.