Montana Field Guide

Plants: Acrocarpous (Vitt 1988). Growing in crowded, upright clumps (Crum & Anderson et al. 1981); green or green with buttery tones above, brownish below; leaves lax, leaving some of the leaf bases visible, barely tufted with slightly crowded leaves at the top. Stems noticeably covered with long (FNA 2007), russet rhizoids, sometimes with a few short branches above; central strand absent (Flowers 1988).

Leaves: Strongly spiraled and retaining most of the leaf tips when dry, sometimes fragile, prominently wavy, upright or spreading somewhat (FNA 2007) and flexuose when moist, long, narrow, and lance-shaped, tapering to a long narrow point from a wider base, cupped (Lawton 1971), 4-6.5 mm in length; margins flat (Malcolm & Malcolm 2009); costa shiny, excurrent, merging with the lamina to form an apiculus (Crum & Anderson et al. 1981).

Leaf Cells: Laminal cells 1-layered; lower laminal cells hyaline and fine-walled, conspicuously distinct from the papillose upper laminal cells (FNA 2007), the sudden demarcation between them V-shaped (Malcolm & Malcolm 2009); upper laminal cells chlorophyllose, isodiametric, covered with C-shaped papillae on both sides; costa with epidermal cells, 1 row of guide cells, and dorsal and ventral stereid bands (FNA 2007).

Fruit ripens the last part of spring and into the summer (through August) (FNA 2007).

The spiraling and contorted leaves, very wavy margins, and long glossy apiculus provide a combination of characteristics not found in other closely related species (FNA 2007).

Stunted plants may appear similar to T. fragilis, but T. fragilis has firmer and more upright leaves that are typically delicate (FNA 2007).

Trichostomum tenuirostre, which also has twisting and curly leaf apices, has clear basal cells that run along the leaf margins only a small distance rather than more considerably and forming the “V” as in Tortella tortuosa (Crum & Anderson et al. 1981).

Calcareous rock fissures, shelves, boulders in open or forest-canopied habitats, dry wooded slopes, or wetter habitats such as humus along riverbanks (FNA 2007) and peaty soil or decaying wood in Cedar swamps. Elevation: 330-12,470 feet (FNA 2007).

Dioicous. Perigonial leaves not as long as vegetative leaves; interior perichaetial leaves not as contorted as vegetative leaves, light yellow (Lawton 1981). Seta 9-27 mm in length (seldom longer). Capsule 1.5-3.3 mm in length (Crum & Anderson et al. 1981), yellow to russet (Lawton 1971); peristome teeth filiform (FNA 2007), twisted (Lawton 1971), making 2-3 revolutions (Flowers 1988).