John A. Christy

Hypnum [unranked] Limbella Müller Hal. in H. G. A. Engler, Forschungsr. Gazelle 4: 37. 1889; Hypnodendron subg. Limbella (Müller Hal.) Brotherus

Plants small to large, yellow-green to blackish. Stems , irregularly branched to subpinnate beyond ± naked stem; hyalodermis absent, central strand present; paraphyllia absent; rhizoids at stem base, densely matted, not forming tomentum, smooth; axillary hair distal cells 4-7, hyaline. Stem leaves spreading, straight or incurved, ovate-oblong or ovate-lanceolate, not plicate, 1.5-3.5 mm; base not decurrent; margins plane, serrulate to serrate, occasionally entire, limbidia conspicuous or poorly developed, usually submarginal, (2-)4-stratose, cells incrassate; apex acuminate to subulate, or cuspidate; costa single, strong, percurrent to short-excurrent; alar cells undifferentiated; basal laminal cells usually oblong; distal cells subquadrate to rhomboidal, 3-36 × 3-18 µm. Branch leaves similar. Sexual condition dioicous. [Capsule horizontal to cernuous, oblong-cylindric, asymmetric, sometimes arcuate; peristome hypnoid; exostome margins dentate; endostome cilia appendiculate. Spores 14-18 µm].

Species 2 (1 in the flora): Oregon, Pacific Islands (Hawaii).

Species of Limbella have been included previously in Sciaromium (Mitten) Mitten, a synonym of Echinodium Juratzka (S. P. Churchill 1986). Limbella tricostata (Sullivant) Brotherus is endemic to Hawaii.

SELECTED REFERENCES Christy, J. A. 1987. Limbella fryei (Williams) Ochyra distinct from L. tricostata (Sull.) C. M. (Musci: Amblystegiaceae). J. Hattori Bot. Lab. 63: 395-410. Ochyra, R. 1987b. On the taxonomy and family placement of the moss genus Limbella (C. Muell.) Broth. J. Bryol. 14: 465-485.

Lower Taxon

• Limbella fryei (R. S. Williams) Ochyra