Campylopus praealtus (C.M.) Par.

P. A. Florschütz, 1964, Flora of Suriname, volume VI, part I, Leiden: Brill : 70-71

1. Campylopus praealtus (C.M.) Par. Ind. Bryol. Suppl. 96. 1900.

Dicranum praealtum C.M. Hedwigia 37: 227. 1898.

Type specimen: Sintenis s.n., Porto Rico (NY).

Very robust plants, growing in thick mats. Stems simple of very sparingly branched, especially below a perichaetium, densely and equally foliate, up to 10 cm long. Leaves rigid, erect-spreading, lanceolate, concave, apex acute, about 8-13 mm long and 1,5 mm wide, margin entire, denticulate only at extreme apex. Costa very strong and broad, at base about 0,85 µ wide, excurrent, in cross-section showing a dorsal layer of stereids and a layer of very wide, thin walled cells at ventral side. Cells near leaf base elongate, linear, with very thick and strongly pitted walls, about 50-70 µ long and 6-10 µ wide, towards leaf base gradually shorter and wider, oval, 30 µ long and 20-25 µ wide, at extreme base quadrate, little inflated, but forming conspicuous auricles, towards margin suddenly hyaline, with thin, not pitted walls, in 6-8 rows, forming a very conspicuous, broad, hyaline border, extending to 1-2 mm below apex; cells towards apex gradually more irregular-rhomboidal to linear, 18-45 µ long and 3-6 µ wide, walls inconspicuously pitted, border cells very long and narrow. Apex often hyaline, toothed all around. Apparently dioicous; perichaetia clustered at end of stem, but appearing lateral when capsules are mature. Outer perichaetial leaves with an ovate base about 1 cm long, suddenly narrowed to the long, slender, 3-5 mm long point, which is nearly filled by the costa; inner perichaetial leaves with a sheathing base, 4 mm long and a slender point, 4 mm long, hyaline at apex. Basal cells rectangular to hexagonal, thin-walled and hyaline. Seta 1,5-2 cm long, cygneous. Capsule asymmetric, 3,5 mm long, strongly furrowed. Peristome teeth 0,5-0,6 mm high, cleft half way down, the basal part vertically striate, the forks finely and densely papillose. Lid conic, about 1 mm long. Calyptra, at least when young, not ciliate. (Fig. 19)

Distribution: Porto Rico, Northern South America.

Substratum not indicated. Only once collected in Suriname, Wilhelmina Mountains, 1040 m. Not collected in British or French Guiana. Specimen examined: B.W. 7136.

A very remarkable plant and one of the largest acrocarpous mosses of the region. The size of the leaves, the broad costa with very wide ventral cells as seen in cross-section and the conspicuous, hyaline border are very distinctive characters. The sporophyte is described here for the first time.