Campylopus Moss

Campylopus angustiretis differs from all other species of the genus by its elongate distal laminal cells. Thus it is not certain if it actually belongs to this genus. Because of the lack of sporophytes a decision cannot be made. It has been treated as a variety of the sympatric C. surinamensis and superficially resembles certain expressions of that species (described as C. donnellii). It differs, however, by a narrower costa, the awn not coarsely serrate, the transverse section of the costa showing larger hyalocysts, and distinctly keeled leaves.

Plants 5-20 mm, in loose light green to gray-green mats, evenly foliate with distant, spreading leaves, the distal ones sometimes forming a comal tuft, not tomentose. Leaves 6 mm, lanceolate, keeled, long-decurrent, gradually narrowed into a fine channelled, concolorous, straight tip that is denticulate at the outermost apex; alar cells large, inflated and auriculate, hyaline; basal laminal cells rectangular, moderately thick-walled, narrower and thin-walled in several marginal rows; distal laminal cells elongate, 6-10:1, not sharply delimited from the basal laminal cells; costa relatively narrow, filling ¹/4-¹/3 of leaf width, excurrent, in transverse section with a adaxial band of hyalocysts that are slightly smaller than the median deuters, abaxially with groups of stereids, smooth at back. Specialized asexual reproduction not known. Sporophytes not known.

Dicranum angustirete Austin, Bot. Gaz. 4: 150. 1879; Campylopus delicatulus R. S. Williams; C. gracilicaulis subsp. angustiretis (Austin) Kindberg; C. surinamensis var. angustiretis (Austin) J.-P. Frahm

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.