6. Cleistocarpidium Ochyra & H. Bednarek-Ochyra, Fragm. Florist. Geobot. 41: 1035. 1996.
[Greek kleistos, unopened, and karpos, fruit, alluding to indehiscent capsule without operculum]
Kwok Leung Yip
Plants loosely tufted, yellow-green. Stems 0.3-0.8 cm, simple, rhizoids sparse. Leaves loosely erect when dry, subulate from an ovate-lanceolate to narrowly obovate base, margins largely plane, entire, serrulate along the subula; costa excurrent, subula flexuose; cells 1-stratose, linear distally, laxly oblong-rhomboidal proximally; perichaetial leaves in transverse section with 6-7 large guide cells closer to the adaxial side, two stereid bands on either side of guide cells in apical sections, but only one disconnected stereid band at leaf middle and base; laminal cells laxly oblong-rhomboidal proximally, linear distally, smooth. Sexual condition paroicous (and reportedly autoicous), antheridia naked; perichaetial leaves proximally broadly ovate, abruptly subulate. Seta short, erect. Capsule cleistocarpous, immersed, ovoid, broader at the base; stomata numerous, scattered in proximal half of the capsule. Calyptra mitraeform to cucullate, regularly 4-lobed at base. Spores globose, densely and finely papillose.
Species ca. 2 (1 in the flora): North America, Europe.
The calyptra of Cleistocarpidium is 4-lobed, often with a deep indention on one side. The cryptoporic stomata are confined to the proximal half of the capsule, but not restricted to the extreme base as is the case with Pleuridium. The pale, ovoid capsule may be slightly asymmetric. This genus includes Sporledera in the sense of European authors but not of Hampe.