BFNA Title: Myurella
Schimper in P. Bruch, W. P. Schimper &
Dale H. Vitt
Plants thread-like. Branches simple to irregularly branched, erect-ascending to creeping; paraphyllia absent. Leaves imbricate and erect to wide-spreading and widely spaced, concave, ovate, blunt, and sometimes apiculate; margins erect, subentire to serrulate; laminal cells rhomboidal, firm-walled, nearly smooth to strongly 1-papillose abaxially; costa short, single, double, weak or almost absent; alar cells not differentiated. Sexual condition dioicous. Sporophytes rare. Capsule erect to nearly horizontal, cylindric, smooth; peristome double, well-developed. Calyptra cucullate.
Species 9 (3
in the flora); worldwide except
1. Leaf cells with one, large stout papilla abaxially . . . 2. Myurella sibirica
1. Leaf cells smooth or prorulose abaxially.
2. Leaves imbricate, erect, rounded-obtuse to occasionally short-apiculate . . . . . . . . . . . . . . . . . . . . . .1. Myurella julacea
2. Leaves distant, wide-spreading, shortly acuminate-apiculate . . . 3. Myurella tenerrima
1. Myurella julacea (Schwägrichen) Schimper in P. Bruch, W. P. Schimper & W. Gümbel, Bryol. Eur. 6: 41. 560. 1853
Leskea julacea Schwägrichen in J. A. Schultes, Reise Glockner 2: 363. 1804
Plants yellow-green. Stem leaves crowded, imbricate, erect, about 0.3 mm, rounded to ovate, obtuse, occasionally with a tiny apiculus; margins serrulate to subentire; distal laminal cells faintly prorulose.
Calcareous habitats, including seepages, rock crevices, and fens; frequent in boreal and Arctic areas, common in western montane areas with calcareous rocks; Greenland; Alta., B.C., Man., N.B., Nfld., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Alaska, Calif., Colo., Conn., Maine, Mass., Mich., Minn., Mont., N.Y., Vt., Wash., Wis., Wyo.; Europe; Asia.
This species is distinguished as the small, worm-like plants, yellow-green in color. The leaves are concave and tightly overlap. It is easily distinguished from the other two species of the genus by obtuse leaves that have at most a tiny apiculus.
2. Myurella sibirica (J. K. A. Müller) Reimers, Hedwigia 75: 292. 1937
Hypnum sibiricum J. K. A. Müller, Syn. Musc. Frond. 2: 418. 1851; Myurella careyana Sullivant; M. sibirica var. tenella (Habeeb) H. A. Crum, Steere, L. E. Anderson
Plants glaucous-green. Stem leaves distant, loosely erect to wide-spreading; about 0.4--0.6 mm, ovate, long-apiculate to slenderly acuminate; margins irregularly dentate to spinose-dentate; distal laminal cells strongly papillose, each cell with a single, high, central papilla.
Mesic, calcareous rock crevices; B.C., N.B., Nfld., N.W.T., N.S., Nunavut, Ont., Que., Yukon; Alaska, Ark., Ill., Ind., Iowa, Ky., Maine, Md., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Vt., Va., W.Va., Wis.; Europe; n Asia.
is not uncommon in the East, but becomes rare in northwestern
3. Myurella tenerrima (Bridel) Lindberg, Musci Scand. 37. 1879
Pterigynandrum tennerrimum Bridel, Mant. Musc. 132. 1819
Plants pale to yellow-green. Stem leaves widely spaced, erect to spreading, 0.3--0.4 mm, rounded to ovate, acuminate to shortly apiculate, the apiculus ± recurved; margins serrulate; distal laminal cells faintly prorulose.
An Arctic and northern boreal species of moist calcareous habitats; infrequent in fens, rock crevices, and tundra meadows; Greenland; Alta., B.C., Man., Nfld., N.W.T., Nunavut, Ont., Que., Yukon; Alaska; Europe; n Asia; n Africa.
This species is similar to M. julacea in color and general habit, but with widely spaced leaves that end in a well-developed, often recurved apiculus. It differs from M. sibirica in features of the leaf papillae and margins.