Groutiella

• Authority

  Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)

• Family

  Orthotrichaceae

• Scientific Name

  Groutiella

• Description

  Genus Description - Plants in dense, spreading dull, green or red-brown, tomentose mats, usually on trees, sometimes on rock. Stems creeping, with numerous erect, usually simple branches up to 2 cm high. Leaves contorted and often irregularly spiral-twisted around the stem, sometimes ± undulate when dry, erect- to wide-spreading when moist, lanceolate to lingulate, rounded-obtuse and mucronate or gradually narrowed to a linear, fragile subula, sometimes rugose; margins entire, plane or broadly reflexed; costa strong, ending just below the apex, percurrent or excurrent; upper cells small, rounded-hexagonal, smooth, flat or bulging; inner basal cells scarcely differentiated, rounded, thick- to thin-walled; marginal basal cells elongate-linear, usually extending upward as a border 1/4 the leaf length or more (sometimes to the apex); cells at the insertion sometimes enlarged and yellowish. Dioicous. Perigonia terminal or with dwarf male plants on leaves and tomentum. Vaginula sometimes densely radiculose. Setae up to 13 mm long, smooth; capsules fully exserted, 1-4 mm long, oblong-ovoid to cylindric, smooth or obscurely phcate when old, heavily cutinized, with 1-6 internal cell layers, some of which extend into the peristome region; stomata superficial, in the neck; operculum ± convex-conic, long-rostrate; peristome rudimentary, usually consisting of a low, multistratose, papillose membrane. Spores 15-32 µm, isosporous or anisosporous, papillose. Calyptrae conic-mitrate, covering less than 1/2 ofthe capsule, plicate, smooth, naked, ± lacerate or divided into numerous lobes.

• Discussion

  These species, formerly in Macromitrium, were segregated by Bescherelle (1872a) as Micromitrium and later by Grout (1946) as Craspedophyllum. Both names are later homonyms, and in 1950 Crum and Steere proposed Groutiella as a replacement. The genus is characterized by creeping stems producing short, erect branches and contorted and spirally-twisted leaves. The rounded basal cells are bordered by elongate cells from less than one-third to nearly the entire leaf length. Sporophytes are produced at the end of short branches or in axils of short, divided branches. They are characterized by a rather large, more or less ovoid-cylindric, tough-walled capsule and a peristome reduced to a low papillose membrane. The calyptra, lobed or lacerate and naked, covers less than 1/2 of the capsule. Leaf shape is the most important feature in identification. Groutiella chimborazensis is by far the most common species, followed by the not uncommon G. tomentosa, both in the interior mountains and in coastal areas. Groutiella apiculata and G. tumidula are rare and restricted to eastern coastal areas. The Mexican species generally grow on trees, but all occur on rocks as well.