Controversial Weissia Moss

This treatment of Weissia controversa follows the study of A. Stoneburner (1985), which justifiably included W. andrewsii, and, agreeing with H. A. Crum and L. E. Anderson (1981), pointed out the great variation in peristome development including occurrence of both eperistomate and peristomate capsules in the same collection. The present treatment includes all flora area reports of W. condensa, a morphologically distinct European species with characters as listed in Excluded Species. Rhizoidal gemmae were reported by W. D. Reese (1988) but these are apparently rare. Weissia viridula Bridel is an illegitimate name that has been much used for this taxon.

Plants small, 4–6(–10) mm high, bright green or yellowish green, in dense tufts. Stems erect, simple or irregularly branched. Leaves often crowded at stem tips, crisped when dry, spreading when moist, narrowly lanceolate, sheathing at base, upper lamina often channeled, acuminate at apex; margins strongly incurved above the leaf base, entire or crenulate by projecting papillae; costa rather stout, usually shortly excurrent, ending in sharply mucronate tips; upper leaf cells rounded hexagonal, thin- to evenly thick-walled, papillose, with bifid or branched papillae; basal cells sharply differentiated, rectangular, sometimes forming a V-shaped leaf base, mostly thin-walled, smooth, hyaline. Autoicous. Setae 5–8 mm long; capsules erect, oblong-ovoid; opercula conic-rostrate, with an oblique beak; peristome teeth short, linear-lanceolate, papillose or sometimes rudimentary.

Leaves short- to long-lanceolate, base weakly differentiated to ovate, shoulders weak or absent, distal laminal margins strongly and usually but not always sharply incurved or inrolled, apex plane to channeled, acute, mucro usually weak, of 1-5(-8) cells; costal adaxial stereid band smaller than the abaxial; distal laminal cells 6-13 µm wide. Sexual condition monoicous. Seta elongate, 0.3-0.8 cm. Capsule stegocarpic, long-ovate to cylindric, operculum differentiated, falling, peristome present, teeth rudimentary to lanceolate, or occasionally absent.

Distribution: China and nearly worldwide.

Habitat: on rocks, soil in shaded or open disturbed places.

Weissia controversa var. minutissima (Par.) Wijk & Marg., Taxon 10: 26. 1961. Weissia viridula var. minutissima (Par.) P.-C. Chen, Hedwigia 80: 161. 1941. Hymenostomum minutissimum Par., Index Bryol. Suppl. 189. 1900. Weissia longiseta Lesq. & Jam., Proc. Amer. Acad. Arts 14: 135. 1879. Weissia microtheca Thér., Ann. Cryptog. Exot. 5: 169. 1932. Type. China: Fujian (Fukien), Fu-zhou City, H. H. Chung 277. Weissia sinensis Card. & Thér., Bull. Acad. Int. Géogr. Bot. 19: 18. 1909. Type. China: Guizhou (Kweitschow), Tou-schan, 1904, Cavalerie 1649 (isotype H). Weissia sulcata Thér., Ann. Cryptog. Exot. 5: 169. ic. 1932. Type. China: Fujian (Fukien), Buong Kang, H. H. Chung 54. Weissia viridula Hedw. ex Brid., Muscol. Recent. Suppl. 4: 38. 1819 [1818], hom. illeg.

Gymnostomum rauanum Austin; Mollia viridula (Withering) Lindberg; Weissia andrewsii E. B. Bartram; W. brandegeei Austin; W. controversa var. australis (Austin) Schornherst; W. controversa var. longiseta (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson; W. controversa var. wolffii (Lesquereux & James) H. A. Crum, Steere & L. E. Anderson; W. curvicaulis Bridel; W. longiseta Lesquereux & James; W. microodonta Hedwig; W. viridula var. nitida Renauld & Cardot; W. wolfii Lesquereux & James

Weissia controversa, the green-tufted stubble-moss, is a species of moss in the Pottiaceae family.

It is widely found in all continents, except in Antarctica.

Weissia controversa is a hermaphroditic species. The plants usually grow to less than 1 cm in height and the spores measure 14-20 µm.