Haplocladium microphyllum

   Plants to 4 cm long in intricate, sparingly branched deep green to yellow green mats. Stems and branches little differentiated. Leaves to 1 mm long, 4–5: 1, ovate-lanceolate, gradually tapering at about 2/3 to the narrow acumen. Leaves somewhat concave, erect and overlapping with the apices rigidly erect, not catenulate, little distorted when dry. Margins plane, decurrent by 1–2 smooth and elongate cells, serrate throughout, with the teeth often somewhat recurved in the plane of the leaf. Median cells often very irregular in size and shape, mostly elliptic to rhomboidal with the walls evenly thickened throughout, 4–6 µm wide, 1.5–4: 1, high unipapillose on both surface with the papillar salients up to 4 µm high and covering most of the lumen. Juxtacostal cells, especially the basal, longer and with lower papillae. Marginal cells in one to several rows abruptly longer than adjacent laminal cells, typically smooth. Apical cell typically very short, often isodiametric. Alar cells not differentiated. Costa ending in acumen within a few cells of leaf apex, mostly prorate spinose dorsally in its distal portions. Axillary hairs not offset from leaf insertion, to 60 µm long, 3 celled, with one poorly differentiated basal brown cell. Pseudoparaphyllia arched over bud, broadly triangular to orbicular, very coarsely serrate, high papillose.

   Dioicous with male plants somewhat smaller than the females. Perichaetia on main stems with bracts very pale to bleached green, somewhat longer than vegetative leaves. Seta brown to deep red brown, papillose, to 1 cm long. Urn red brown, strongly inclined to nearly pendent, oblong and asymmetric, to 2: 1, to 1.5 mm long, strangulate when dry. Operculum rostrate, about 1/2 as long as urn. Exothecial cells short rectangular, 1.5–3.0: 1, to 25 µm wide, rather thick walled with strong corner thickenings. Annulus well differentiated, not revoluble. Exostome to 400 µm long, red-brown, horizontally striate at base, nearly smooth distally. Endostome almost as long as exostome, with basal membrane comprising about 1/2. Endostome processes lightly papillose, keeled and perforate, with 2–3 cilia. Spores smooth, to 14 µm in diameter.

No Vouchers.

Literature: Harthill et al. 1979; Koch 1950a; McCleary 1972; Steere 1954. As Hypnum calyptratum Sullivant 1856. As Thuidium microphyllum Sayre 1940.

No Distribution in California.

Illustration References: Malcolm et al. 2009 p. 130; Crum and Anderson 1981; Smith 1978.

No illustrations found in database.

Elevation by latitude plot for Haplocladium microphyllum
   in California