Montana Field Guide

"Nutans" means “drooping,” in reference to the pendent capsule (Crum 1981). The common name, “Copper-Wire Moss,” refers to the characteristic color of the setae (Vitt).

Plants: Acrocarpus. Growing in tufts, yellow-green to green, dull or barely glossy (Crum 1981). Stems 0.5-3.5(-10) cm tall (FNA 2014), reddish, mostly unbranched (Crum 1981).

Leaves: Upright or spreading a little(FNA 2014), with slight winding around the stem possible when dry, 2-3 (seldom 4) mm in length, longer and more dense near the top, lance-acuminate (Crum 1981) to ovate-lanceolate (FNA 2014), barely if at all decurrent; margins toothed distally, sometimes curved back and downwards when dry (Lawton 1971); costa well-developed (Crum 1981), ending just below, at, or rarely shortly extending beyond the apex. Leaves of perichaetium long-lanceolate, those of perigonium ovate-lanceolate (FNA 2014).

Leaf Cells: Incrassate, thin or narrowly rhombic (Crum 1981); distal medial cells 6-sided or rhombic (FNA 2014), the basal cells rectangular and a little shorter than the distal ones (Crum 1981).

Capsules ripen April-June (FNA 2014).

P. nutans is similar to P. cruda structurally and in size. P. nutans, however, distal cells with moderately thick walls (Crum 1981) rather than thin, has leaves slenderly lanceolate rather than ovate-lanceolate, and is smaller and dull in comparison to the yellow-green/gold iridescence of P. cruda (Vitt 1988; FNA 2014).

On rotten stumps and logs, occasionally on burned wood, on soil at base of trees, in bank fissures, from densely-canopied to more open areas, disturbed areas, in Sphagnum mounds(Crum 1981, FNA 2014). Vitt (1988) specifically notes that it frequently occurs in forests of the north and mountains, often to be found on “just about every log in white spruce-pine forests of the Rockies and Interior British Columbia areas.”

A. J. Shaw’s P. sphagnicola (1982), that grows in Sphagnum, is treated here as P. nutans (FNA 2014).

Autoicous; seldom dioicous. Setae 14-33 (seldom up to 50) mm in length, flexuous, yellow-, red- or orange-brown. Capsules oriented 80-100 degrees from vertical, orange or brown with orange tints; capsule neck making up about 1/3 to 1/2 of the capsule’s length, sometimes greatly contracted when dry; peristome teeth with fine papillae; exostome teeth yellow or orange-brown; endostome hyaline or seldom brown with orange tints (FNA 2014), with wide keels open or perforate, and 2 or 3 short to long cilia with knobbed fine tips inbetween the teeth (Crum 1981, FNA 2014).

Usually no specialized vegetative reproduction occurs (FNA 2014).