Fissidens yucatanensis Steere 1935

Fissidens yucatanensis Steere, Am. Jour. Bot
22:397. 1935.
■Plants small, 4-8 mm. high, light green, unbranched, somewhat caespitose, flaccid, erect; leaves 4-12 pairs, the lower smaller, distant, the upper larger, crowded and imbricated, with a stout flexuous costa confluent with the border, and occasionally excurrent into a small apiculus, oblanceolate to ligtdate with a wide, obtuse or somewhat acute apex, the narrow borders and the straight costa not reaching the apex; vaginant laminae reaching slightly more than half-way to the apex; dorsal lamina ceasing abruptly at the base, not at all decurrent, crenate at the lower angle by the projecting marginal cells; upper leaf-cells irregularly polygonal to hexagonal, 24-32 /x in diameter, not elongated, bearing a single large distinct papilla on the middle of each exposed surface, except on the vaginant laminae, where the inner face is smooth, the single row of cells adjacent to the costa often larger and nearly hyaUne, those of the basal region larger, about 48 m long, rectangular, those at the extreme base smooth; dioicous; antheridia and archegonia in terminal clusters; sporophyte unknown.
Type locality: Muna, Yucatan (Steere 2129). Distribution: Muna and Uxmal (Steere 2034), Yucatan.