XX. ROELLIACEAE J. R. Spence & H. P. Ramsay
John R. Spence
Plants acrocarpous. Stems rosulate, unbranched, stolons absent; rhizoids sparse, confined to stem base, micronemata and macronemata absent. Leaves large, broadly ovate to obovate, base more or less straight at insertion, decurrent, laminal surface finely rugose; margins plane distally, revolute proximally, serrate in distal half, rarely nearly entire, 1-stratose, limbidium present, well developed, apex acute, sometimes mucronate, costa slender, green-yellow, percurrent, transverse section with reduced stereid band or stereids nearly absent; basal adaxial supracostal cells long-rectangular, laminal cells large, obscurely heterogenous, proximal cells long-rectangular, longer than distal cells, medial cells generally similar to distal cells, distal cells hexagonal to rhomboidal, not oblique to the costa, thin-walled, walls not distinctly pitted, alar cells similar to juxtacostal cells. Specialized asexual reproduction absent. Sexual condition dioicous; perigonia and perichaetia terminal, perigonia enlarged, forming a rosette, inner leaves highly differentiated, often narrower with a weaker costa. Seta 1(--2). Capsule nutant, long-exserted, long-pyriform to elongate-cylindric, sometimes curved, hypophysis well-differentiated; annulus present, revoluble; operculum convex, short-conic; peristome diplolepidous-alternate, exostome teeth lanceolate-acuminate, papillose, narrowly bordered, trabeculate, lacking pores, endostome free, pale, with high basal membrane, segments keeled, perforate, cilia long, (2--)3--4, nodose. Calpytra fugacious, cucullate, small, smooth. Spores shed singly, small, 10--18 \um.
Genus 1: w
is a large,
distinctive monotypic endemic moss found in high elevation and other
cool-climate forests of western
1. ROELLIA Kindberg, Gen. Eur. & North Amer. Bryin. 37. 1897
Plants robust, as scattered individuals, or forming open turfs, usually pale green. Leaves shrunken to imbricate or somewhat contorted when dry, erect-spreading when wet, laminal cells 2--4:1. Seta long, straight, yellowish, becoming red-brown with age. Capsule brown, exothecial cells near mouth quadrate or short-rectangular, thick walled, often reddish, in 4--5 rows, proximal cells longer, long-rectangular with somewhat sinuose walls. Spores smooth to finely papillose, pale yellow-brown.
Species 1: w
1. Roellia roellii (Röll) H. A. Crum, Bryologist 70: 107. 1967
Mnium roellii Röll, Bot. Centralbl. 44: 420. 1890; Bryum lucidum E. Britton; B. sandbergii Holzinger; Mnium lucidum (E. Britton) Brotherus; Roellia lucida (E. Britton) Kindberg; R. simplex (Macoun & Kindberg) Kindberg
Stems 1--4 cm. Leaves sometimes tinted pink or red below, small and scale-like proximally, enlarged above, rosette leaves 4--7 mm; lamina cells 90--150 x 30--50 \um, cells along margin narrower and thicker walled, forming a somewhat distinct border of 2 layers, basal cells more regularly rectangular, often somewhat narrower and longer than distal cells. Perigonia conspicuous, with abundant yellow antheridia in disk-like heads. Perichaetial leaves similar to stem leaves, somewhat smaller. Capsule 4--7 mm.
Capsules rarely produced, mature summer--fall (July--September). Litter and rich humus under trees and shrubs, mostly montane and subalpine coniferous forests; 0--3200 m; Alta, B.C.; Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo.
is rare in