Isopterygiopsis muelleriana

(Schimper) Z. Iwatsuki

J. Hattori Bot. Lab. 33: 379. 1970.

Basionym: Plagiothecium muellerianum Schimper Syn. Musc. Eur., 584. 1860
Synonyms: Isopterygium muellerianum (Schimper) A. Jaeger
Treatment appears in FNA Volume 28. Treatment on page 550. Mentioned on page 551.

Plants in thin mats, yellowish. Stems 2 cm, 0.8–2 mm wide, complanate-foliate; epidermal cells large, walls thin, cortical cells in 1–several layers, small, walls thick. Leaves somewhat rigid, erect-spreading, crowded, imbricate, ovate- to oblong-lanceolate, weakly concave, 0.5–1.5 × 0.3–0.5 mm; margins plane, entire or minutely serrulate; apex acuminate, often abruptly so; alar cells not differentiated or sometimes short-rectangular, 8–24 × 4–7 µm; medial laminal cells 55–94 × 3–6 µm. Specialized asexual reproduction sometimes present as propagula, 66–96 × 6–12 µm, of 2–6 cells. Sexual condition dioicous. Seta brown to reddish, 0.6–1.2 cm. Capsule erect or rarely ± cernuous, yellowish to orange-brown, ellipsoid to ovoid, straight, 0.5–1.5 mm; operculum conic to obliquely rostrate, 0.4–0.8 mm. Spores 8–12 µm.

Phenology: Capsules mature fall (Sep).
Habitat: Acidic cliffs, rock outcrops, boulders in woods
Elevation: moderate elevations (300-1200 m)


V28 856-distribution-map.gif

B.C., N.B., Nfld. and Labr., N.W.T., N.S., Ont., Que., Yukon, Alaska, Ark., Conn., Ill., Ky., Maine, Md., Mich., Minn., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Tenn., Utah, Vt., Va., Wis., Mexico (Distrito Federal), Europe, Asia.


Isopterygiopsis muelleriana is easily distinguished from the other two species in the genus by stems that are complanate-foliate, pectinate, appearing concave on the adaxial surface because of the upturned leaves, and by epidermal stem cells that are very large and thin-walled. Inclusion here of the Utah record is based on S. Flowers (1973).

Selected References


Lower Taxa

Robert R. Ireland Jr. +
(Schimper) Z. Iwatsuki +
Plagiothecium muellerianum +
B.C. +, N.B. +, Nfld. and Labr. +, N.W.T. +, N.S. +, Ont. +, Que. +, Yukon +, Alaska +, Ark. +, Conn. +, Ill. +, Ky. +, Maine +, Md. +, Mich. +, Minn. +, Mo. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, S.C. +, Tenn. +, Utah +, Vt. +, Va. +, Wis. +, Mexico (Distrito Federal) +, Europe +  and Asia. +
moderate elevations (300-1200 m) +
Acidic cliffs, rock outcrops, boulders in woods +
Capsules mature fall (Sep). +
J. Hattori Bot. Lab. +
Illustrated +
Isopterygium muellerianum +
Isopterygiopsis muelleriana +
Isopterygiopsis +
species +