Monographs Details: Anacamptodon
Authority: Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
Description:Genus Description - Plants slender but ± medium-sized, in dark-green, often lustrous, dense mats. Stems creeping, irregularly branched, not particularly fragile; in cross-section with small cells surrounding larger ones, central strand none; paraphyllia none; pseudoparaphyllia filamentous to narrowly foliose; axillary hairs (only seen in A. splachnoides) 2-celled, with a short brown basal cell and a hyaline distal cell ca. 3 X longer than the basal one. Stem and branch leaves similar, ± laxly foliate, loosely appressed to homomallous, lanceolate to ovate, gradually acuminate, somewhat concave, not or short-decurrent; margins occasionally bordered by elongate cells, the border rarely bistratose, entire to serrulate, plane or recurved below; costa single, often strong, ending from near or below midleaf to percurrent, not projecting as a spine; cells rhombic to long-rhombic, smooth, firm-walled, often becoming longer in the acumen; alar cells gradually differentiated, subquadrate. Asexual propagula none. Autoicous. Perichaetia along stems, conspicuous; leaves erect, lanceolate to ovate-lanceolate, gradually to ± abruptly acuminate; margins entire to serrulate, plane; costa single, slender; cells long-rhomboidal to long-hexagonal, smooth, firm-walled; alar cells poorly differentiated. Setae elongate, smooth, erect, straight or curved at base; capsules exserted, erect, symmetric, cylindric to urceolate, strongly constricted below mouth when dry; exothecial cells ± isodiametric, straight-or wavy-walled; annulus differentiated; operculum apiculate to rostrate, often oblique; columella cylindric with an expanded subglobose apex, ending near midurn; peristome double, inserted below the mouth, exostome teeth 16, often paired, brown, triangular, tightly reflexed when dry, gradually tapered and not shouldered, on the front surface with a zig-zag median line, densely papillose, not trabeculate at back, smooth; endostome lacking a basal membrane, segments 8 or 16, slender, keeled, perforate or not, cilia none. Spores spherical, finely papillose. Calyptrae cucullate, naked, smooth.
Discussion:Discussion. Anacamptodon is characterized by slender plants with unicostate leaves. The cells are short and firm-walled, and gradually differentiated in the basal angles. The sporophytes are small, with erect capsules borne on setae either straight or curved at base. When dry, the capsule is strongly constricted below the mouth and the exostome teeth are tightly recurved against the urn. The genus is distinct from Fabronia in the stronger costae, nonfragile stems, and double peristome with reflexed, papillose teeth.
Anacamptodon was treated for tropical America by Buck and Crum (1978) and modified by Buck (1980a, 1981a). The interpretation of the peristome was particularly problematic but resolved in the last-cited paper (Buck, 1981a) and illustrated in elegant detail by Anderson and Palmer (1982).
In the West Indies we have only a single, poorly collected species.