Bryologist 53: 145. 1950.

Etymology: For Abel Joel Grout, 1867 – 1947, American bryologist
Basionym: Micromitrium Schimper ex Bescherelle Mém. Soc. Natl. Sci. Nat. Cherbourg 16: 190. 1872,
Treatment appears in FNA Volume 28. Treatment on page 42. Mentioned on page 38, 653.

Plants small, in tomentose mats. Stems creeping, branches erect. Leaves contorted and spirally twisted around stem, ± undulate when dry, erect to wide-spreading when moist, lanceolate to lingulate, sometimes rugose; margins entire or denticulate; apex rounded-obtuse and mucronate or acute and subulate; costa percurrent or excurrent; basal laminal cells oblate to rounded; distal cells rounded-hexagonal or irregularly rounded to elliptic-hexagonal, 3–9 µm, smooth; marginal cells distinct from basal. Sexual condition dioicous or pseudautoicous; perichaetial leaves similar to stem leaves. Seta to 11 mm. Capsule exserted; oblong-ovate to cylindric, usually smooth or obscurely plicate when old, not constricted below mouth; stomata superficial; peristome rudimentary; exostome absent; endostome basal membrane usually low, papillose. Calyptra mitrate, conic, ± lacerate, or divided into many lobes, smooth, naked, plicate, covering less than 1/2 capsule. Spores isosporous or anisosporous.


Fla., Mexico, Central America, South America, Asia, Africa, Australia, pantropical regions.


Species ca. 20 (2 in the flora).

In Groutiella, the branches are usually simple, to 2 cm; the leaf margins are plane or broadly reflexed; the basal laminal cells are yellowish; the distal cells are bulging; the marginal cells are elongate-linear basally, extending 1/4 or more the leaf length, sometimes nearly to the apex as a border; and the operculum is more or less convex-conic with a long rostrum.

Selected References



1 Distal leaves widest distally; apex acute, ending in long, linear, fragile subula. Groutiella tomentosa
1 Distal leaves widest mid leaf or distally; apex rounded-obtuse, mucronate, not fragile. Groutiella tumidula