Timmiaceae W. P. Schimper
Authors: Dr. Guy R. Brassard
Plants large, acrocarpous, (1--)2--9(--13) cm, in compact or loose tufts, brownish proximally, bright to yellowish green distally. Stems stiff, erect, mostly unbranched, in cross-section with a cortical region of small, thick-walled cells, a parenchyma of larger, thinner-walled cells, and a distinct central strand; rhizoids abundant, especially on the proximal stems and in the leaf axils, dark reddish-black, coarsely papillose, ca. 15--35 µm wide. Leaves crisped to imbricate (and occasionally inrolled) when dry, erect–patent to spreading when moist, lanceolate or long–lanceolate, with a sheathing, entire base occupying the proximal 1/3--1/6 of the leaf, and a non-sheathing, serrate limb, (1.5--)2--8(--12) mm long, 0.5--1.2 mm wide at mid-limb; costa strong, single, subpercurrent to excurrent, in cross-section (mid–limb) with large guide cells, two bands of stereids, and enlarged abaxial and adaxial cells; cells of limb lamina irregularly isodiametric or quadrate, smooth, papillose or mamillose on adaxial and abaxial surfaces; cells of the sheath lamina rectangular, longer and narrower near the margins, shorter and broader near the limb–sheath transition, smooth on the adaxial surface, smooth or with a series of linearly-arranged, large round papillae on the abaxial surface of the lumens. Sexuality: monoicous or dioicous. Male gametophyte (in dioicous taxa) monopodial, with the stem continuing growth through terminal perigonia. Paraphyses few, of 10--15(--40) cells, filiform, with fusiform tips. Archegonia 1--6 per perichaetium, ca. 1--2 mm. Antheridia 5--40 per perigonium, ca. 1--2 mm. Calyptra linear–cylindrical. Seta terminal, elongate, erect, single or double, 1.4--3.5 cm long. Capsule ca. 2.5--3.0 X 1.0--1.5 mm, pendulous to nearly erect, ovate to oblong–cylindric, smooth or broadly plicate; annulus large, revoluble; operculum hemispheric or conic, with a distinct mamilla at the tip; exothecial cells with smooth or sinuose walls, stomata numerous on the neck or over the entire urn; peristome diplolepideous; exostome of 16 lanceolate teeth sometimes united near the base, 0.5--1.0 mm long, yellow in proximal half, pale or hyaline distally, smooth or papillose proximally, strongly vertically barred and papillose distally, with prominent projecting lamellae on the inner surface; endostome about the same height as the exostome, hyaline or yellowish, with a high basal membrane about half the height of the exostome, and 64 irregularly anastomosing, nodose cilia that are papillose at back and smooth or appendiculate on the inner surface. Spores round, finely papillose, pale yellow or brown, 13--22 µm.
Genera 1, species 4 (1 genus, 4 species in the flora): North America, Eurasia, n Africa, Hawaii, New Zealand.
A small taxonomically isolated family consisting of a single genus, Timmia.