Callicostella depressa (Hedw.) A.Jaeger

Authority

Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.

Family

Pilotrichaceae

Scientific Name

Callicostella depressa (Hedw.) A.Jaeger

Description

Species Description - Plants medium-sized, in ± lustrous, usually golden, sometimes green, often dense mats. Stems creeping, to ca. 5 cm long, often 1-2 cm long, subpinnate or irregularly branched, complanate -foliate; in cross-section with 2-4 rows of smallish firm- to thick-walled cells surrounding large thin-walled cells, central strand none; pseudoparaphyllia none; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Leaves contorted when dry, the lateral ones wide-spreading, the dorsal and ventral ones erect, lateral and dorsal leaves oblong-lanceolate to oblong-ovate, (0.6-)0.85-1.4(-2) mm long, typically abruptly acute to short-acuminate or cuspidate, rarely gradually acuminate, ± symmetric or with one costal fork closer to the margin than the other; margins obscurely bordered, at apex the marginal cells smooth, coarsely and irregularly serrate above, especially at and directly below shoulders, with swollen and bifid teeth, subentire below, plane; costa double, ending ca. 9/10 the leaf length, usually with the distal ½ serrate to crested, always ending in a cluster of 3-6 teeth; cells ± oval or irregularly angled, mostly 1-2:1, usually with 1(-2) papillae over each lumen, thin- to firm-walled, becoming long-rectangular, smooth, firm-walled, and ± porose toward insertion; alar cells not differentiated; ventral leaves pale, similar in size to lateral and dorsal leaves, ± gradually acuminate, with margins serrulate, costa smooth at apex or with 1-2 spines, usually not serrate, and with upper leaf cells long-rectangular to sublinear, often smooth, ± thin-walled. Asexual propagula not seen. Autoicous and/or synoicous. Perichaetia small, inconspicuous, on mature stems; leaves few, pale, ovate-triangular, 0.4-0.8 mm long, gradually acuminate; margins serrulate at extreme apex, subentire below, plane; costa double, ending ca. 5/6 the leaf length, projecting as a single spine at apex, rarely serrate below; cells long-hexagonal, smooth, firm-walled, ± porose. Setae elongate, smooth throughout or somewhat roughened at extreme apex, reddish, 1-1.5 cm long, flexuose, curved at extreme apex; capsules horizontal to pendent, cylindric, 0.75-1.5 mm long, often with a roughened neck; exothecial cells subquadrate to short-rectangular, collenchymatous; annulus none (but see operculum description); operculum conic-long-rostrate, the basal 6-8 rows of cells thin-walled, with nodosely thickened inner walls, sometimes remaining attached to urn at dehiscence; exostome teeth reddish, narrowly triangular, narrowly bordered, on the front surface with a broad pale median furrow with a zig-zag line down it, the plates cross-striolate below, the striolae becoming papillose at midtooth, coarsely papillose above, somewhat trabeculate at back, finely papillose; endostome with a medium-high, finely papillose basal membrane, segments papillose-spiculose, keeled, not or narrowly perforate, with baffle-like crosswalls, cilia none. Spores spherical, finely papillose, 8.5-14 µm diam. Calyptrae mitrate, covering the operculum and apex of urn, irregularly lobed at base, naked, ± roughened at apex, smooth below.

Discussion

1. Callicostella depressa (Hedw.) A. Jaeger, Ber. Thätigk. St. Gallischen Naturwiss. Ges. 1875-76: 352. 1877; Leskea depressa Hedw., Sp. Musc. Frond. 215. 1801; Hypnum depressum (Hedw.) Sw. ex P. Beauv., Prodr. Aethéogam. 63. 1805; Hookeria depressa (Hedw.) Hook. & Grev., Edinburgh J. Sci. 2: 231. 1825; Pterygophyllum depression (Hedw.) Brid., Bryol. Univ. 2: 351. 1827; Schizomitrium depressum (Hedw.) W. R. Buck & Steere, Moscosoa 2: 47. 1983. Plate 22, figures 1-12 Pterygophyllum dominghense Brid., Bryol. Univ. 2: 351. 1827, nom. mid. in syn. Hookeria berteriana Müll. Hal., Hedwigia 37: 247. 1898; Callicostella berteriana (Müll. Hal.) Broth, in Engl. & Prantl, Nat. Pflanzenfam. 1(3): 937. 1907. Discussion. Callicostella depressa is characterized by mostly abruptly acute to short-acuminate leaves with coarsely and irregularly serrate margins. The apices of the costae end in a cluster of spines. Callicostella depressa has been misunderstood and used as a dumping ground for several species. It differs from the closely related C. belangeriana, which is primarily Puerto Rican and Lesser Antillean in distribution, in the abruptly acute to short-acuminate leaves and the terminal cluster of 3-6 (rather than 0-2) spines on the costal apices. Occasional specimens of C. depressa, especially from Jamaica, may have gradually acuminate leaf apices, perhaps due to a drier than typical habitat. However, in these cases the costal apices still have the characteristic cluster of 3-6 spines, while those of C. belangeriana never have more than two. Callicostella depressa also has been confused with smooth-setaed forms of C. pallida. However, in C. pallida the leaf apex is usually broadly rounded and not cuspidate; it always, though, has regularly serrate margins with relatively small teeth rather than the coarsely, irregularly serrate margins of C. depressa.

Distribution

Range. Central America, northern South America; Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico, St. Kitts, Guadeloupe, St. Vincent (most reports from Puerto Rico and the Lesser Antilles, where the species is quite rare, are based on misdeterminations, mostly of C. belangeriana); typically growing on rotten logs, less often on rocks or soil, in humid forests, at 500-1000 m.

Central America| Venezuela South America| Brazil South America| Colombia South America| Ecuador South America| Peru South America| Guyana South America| Suriname South America| French Guiana South America| Cuba South America| Jamaica South America| Haiti South America| Dominican Republic South America| Puerto Rico South America| Saint Kitts and Nevis South America| Guadeloupe South America| Saint Vincent and the Grenadines South America|