Campylopus angustiretis Lesquereux & T. P. James 1884

Campylopus delicatulus R. S. Williams, sp. nov
Flowers and fruit unknown: plants in loose, green mats, with very slender, erect, simple stems 12-15 mm. high, bearing rather distant, nearly straight, widely spreading leaves rather uniformly placed along the stem and of nearly the same size below as at the apex of the stem; stem in cross-section oval-hexagonal, 200 y by 130 y, with a large central strand and walls of mostly 2 or 3 layers of small, thickwalled cells: leaves about 3.5 mm. long, narrowly lanceolate, tapering from near the base to a subtubulose point often sharply denticulate at the apex f ormed by the shortl y excurrent costa ; costa smooth on the back to a lit tle below the apex, about 160 y wide at the base and one third the width of the leaf-base, in cross-section below showing 12-15 large median cells with an equal number of large cells in one row on the upper side and about 2 rows of smaller cells on the under side, with no stereid-band; -alar cells forming a large group, hyaline to reddish-brown and more or less inflated, extending to the costa ; cells just above the alar ones often nearly square, about 20 y wide, soon becoming narrower and elongate, mostly prosenchymatous, with somewhat thickened, not pitted walls, the median cells of the blade 4-6 y wide and up to 40-50 y long.
Type collected at Herradura, province of Pinar del Rio, Cuba, August 27, 1910, E. G. Britton 6523 (herb. N. Y. Bot. Gard.).
Distribution: Pinar del Rio, Cuba.

Campylopus angustiretis (Aust.) Lesq. & James,
Man. 80. 1884.
Dicranum angustirete Aust. Bot. Gaz. 4: 150. 1879.
Plants in rather loose, green to brownish tufts; stems mostly simple, about 3 cm. high, without radicles above: leaves nearly straight, equally spreading all around, rather loosely imbricate below, more or less comose at the summit, the lower ones 3.5-4 mm., the upper about 5 mm. long;, costa just above the alar cells 150 m wide or more, shortly excurrent into a dentate point, slightly ribbed on the back, in cross-section showing a row of thin-walled cells on the ventral side, a median row of cells nearly as large, and a stereid-band below; alar cells palereddish to hyaline, the cells just above broad, short, often nearly square toward the costa, much smaller and narrower toward the margin, in the upper part of the leaf becoming narrowly oblong or rhomboidal to linear and slightly vermicular, 4-6 n wide and about 30 p, long, with rather uniformly thickened walls, not in straight rows.
Type locality: Jacksonville, Florida. Distribution: Known only from the type locality.