Jaffueliobryum Thériot, Rev. Bryol. Lichénol. 1: 192--105, plate 8, figs. 1--5. 1928.
[For Réverend Père Félix Jafuell, 1857--1931, who collected plants in South America, and Greek bryum, moss]
John R. Spence
Plants 3--15(--20) mm, in dense, hoary cushions, dark olive to yellow-green or dull green. Stem leaves broadly ovate to obovate, concave or somewhat keeled, margins plane, smooth to weakly serrate to erose distally, distal lamina mostly 1-stratose, rarely with 2-stratose streaks, specialized laminal and marginal chlorophyllose structures lacking, with variable hyaline awn, short to twice lamina length, distal leaves typically with longer awns; mid-leaf cells isodiametric, oval to irregularly rhomboidal, distal cells becoming hyaline with age, basal cells elongate-rectangular to oblong, with straight, somewhat lax, sometimes weakly hyaline walls. Gemmae absent. Sexual condition autoicous or rarely cryptoicous; perichaetial leaves enlarged, long-awned. Seta short, straight. Capsule erect, immersed, symmetric, globose to oval, annulus differentiated, typically persistent, operculum conic, short to long-rostrate, falling detached from columella. Calyptra campanulate, mitrate, sometimes erose or lobed at base, large, covering 1/2--3/4 of capsule, plicate.
Species 3 (2 in flora): North America, Mexico, Bolivia, central Eurasia (Mongolia, Russia and China).
Jaffueliobryum is a small genus of three species distributed in cold to hot and arid regions where it is usually found on calcareous rock. It appears to be closest to Coscinodon, from which it differs by the broader, less strongly keeled, mostly 1-stratose leaves, strictly autoicous-cryptoicous sexuality, and calciphilous ecology. The third species, J. arsenei, is a larger plant than our species that is endemic to Mexico, and is characterized by a long-rostrate operculum and an exserted capsule.
Flowers, S. 1973. Mosses: Utah and the West. BYU Press, Provo. Churchill, S.P. 1981. A phylogenetic analysis, classification and synopsis of the genera of the Grimmiaceae (Musci). In: V. Funk and D. R. Brooks, eds. Advances in Cladistics. New York. Pp. 127--144. Churchill, S. P. 1987. Systematics and biogeography of Jaffueliobryum (Grimmiaceae). Memoirs New York Bot. Gard. 45: 691--708.