Tetradontium Repandum MossTetradontium repandum, Schwaegr.
Habit and habitat.-Very small, growing in loose clusters on shaded rocks.
Name.-The specific name repandum, the Latin for "curved," refers to the margin of the mouth of the spore-case.
Plant (gametophyte).-Stems very short, bearing little gemmae at the base of thread-like leafy branches.
Leaves.-Ovate-lance-shaped, rigid, red-brown, closely overlapping like shingles.
Leaves at the base of the pedicel (perichaetial leaves).-Ovate and oblong, very concave, vein obscure; scales about the male flowers (perigonium) smaller, thinner, vein absent.
Habit of flowering.-Male and female flowers on the same plant (monoicous).
Veil (calyptra).-Conical, resembling a bishop's mitre and covering the spore-case to the base.
Spore-case. Thick, oval, the margin of the orifice somewhat notched between the teeth.
Pedicel (seta).-Thick and rigid.
Lid (operculum).-Conical, erect, short.
Teeth (peristome).-Simple, of four short, triangular teeth.
Spores.-Mature in autumn.
Distribution.-Near Glen House and at Dixville Notch, White Mountains. Very rare.