Ceratodon

• Authority

  Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part One: Sphagnales to Bryales. Mem. New York Bot. Gard. 69 (1): 1-452.

• Family

  Ditrichaceae

• Scientific Name

  Ceratodon

• Description

  Species Description - Rather small plants in dense, dull tufts. Stems erect, simple or forked. Leaves contorted when dry, keeled, gradually acuminate, usually acute, sometimes ± awned; margins reflexed to revolute, notched or irregularly serrate near the tip; costa subpercurrent to excurrent, prominent at back; cells subquadrate, thick-walled, and smooth above, short-rectangular below. Dioicous. Perigonia swollen and conspicuous. Perichaetial leaves differentiated, sheathing. Setae erect, elongate; capsules suberect and nearly symmetric to strongly inclined and distinctly asymmetric, ± strumose at the base, ± sulcate w h en dry; annulus large and revoluble; operculum conic; peristome teeth 16, split nearly to the base into 2 terete divisions connected at the joints toward the base, bordered, papillose. Spores spherical. Calyptrae cucullate, smooth.

• Discussion

  Asymmetric, ribbed capsules and connections between the forks of the peristome teeth are important features of the genus. The leaves have a considerable resemblance to some of the Pottiaceae (Barbula, for example) in shape, areolation, and revolution of margins, but the cells are not papillose. T h e tendency of the leaves to be keeled and the common excurrency of the costa (at least in C. purpureus) help in recognizing sterile specimens. Reference maybe made to a recent revision of the genus b y Burley and Pritchard (1990).