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BFNA Title: Myurella |
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XX. 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. This species
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.
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