Cyclodictyon albicans (Hedw.) Kuntze
-
Authority
Buck, William R. 1998. Pleurocarpous mosses of the West Indies. Mem. New York Bot. Gard. 82: 1-400.
-
Family
Pilotrichaceae
-
Scientific Name
-
Description
Species Description - Plants medium-sized, in ± lustrous, whitish green to yellow-green, thin to dense, sometimes extensive, ± flat mats. Stems creeping, to ca. 3 cm long, irregularly to pinnately branched, complanate-foliate; in cross-section with a unistratose hyalodermis over 1-3 rows of medium-sized firm-walled cells surrounding large thin-walled cells, central strand none; axillary hairs 2-celled, both hyaline, with a short basal one and an elongate apical one. Leaves not or somewhat contorted when dry, lateral leaves erect-spreading to spreading when dry, wide-spreading when moist, ovate to oblong-ovate to broadly oblong, 1.1-1.9 mm long, ± abruptly acuminate, ± asymmetric, costa strong, ending 3/4-4/5 the leaf length, not tapering distally, sometimes expanded at apex into a small knob, projecting, sometimes subapical cells also projecting, dorsal leaves erect to erect-spreading dry or moist, ovate to oblong-ovate, 1-1.7 mm long, ± abruptly acuminate but more gradual than in lateral leaves, symmetric, costa usually slender, ending ca. 2/3 the leaf length, not expanded at apex, not or only slightly projecting; margins bordered by 2(-3) rows of narrow, elongate cells confluent into a (2-)3(-4)-tiered, serrulate to serrate apiculus of elongate cells, sharply serrulate to serrate above, rarely subentire, subentire below, plane; costa double, in lateral leaves coming closer to basiscopic margin (see other details above); cells hexagonal, thin-walled, 1-2:1, 42-57 X 29-42 µm, <15 between costal tips, often 10-12, usually not differentiated in apex, becoming longer and long-hexagonal to long-rectangular toward the insertion; alar cells not differentiated. Asexual propagula unknown. Autoi-cous. Perichaetia small, inconspicuous, on stems; leaves pale, ± erect, lanceolate-triangular, 0.85-1.3 mm long, gradually acuminate; margins bordered by 2 rows of narrow, elongate cells, confluent into a several-celled apiculus, crenulate to serrulate, plane; costa double, slender, ending ca. midleaf, or absent; cells long-hexagonal, ca. 3:1, thin-walled, scarcely differentiated toward the insertion. Setae elongate, smooth, reddish throughout, darker below, (0.7-) 1.2-1.8 cm long, curved at extreme apex; capsules inclined to pendent, short-cylindric, slightly curved and asymmetric, 1-1.5 mm long; exothecial cells quadrate to short-rectangular, the vertical walls firm, the horizontal ones thin, obscurely collenchymatous; annulus none; operculum long-rostrate from a high-conic base, the rostrum pale; exostome teeth reddish, bordered, on the front surface with a broad median furrow, the furrow pale with a zig-zag median line, the plates cross-striolate below, coarsely papillose above, trabeculate at back; endostome yellowish, with a relatively high, sparsely papillose basal membrane, segments spiculose, keeled, narrowly perforate above, with baffle-like crosswalls, ca. as long as the teeth, cilia none. Spores spherical, low-papillose, 10-14 µm diam. Calyptrae mitrate, constricted and lobed at base, naked, smooth.
-
Discussion
4. Cyclodictyon albicans (Hedw.) Kuntze, Revis. Gen. Pl. 2: 835. 1891; Leskea albicans Hedw., Sp. Musc. Frond. 218. 1801; Pterygophyllum albicans (Hedw.) Brid., Muscol. Recent. Suppl. 4: 150. 1819; Hookeria albicans (Hedw.) Hook. & Grev., Edinburgh J. Sci. 2: 230. 1825. Hookeria lindigiana Hampe, Linnaea 32: 156. 1863; Cyclodictyon lindigianum (Hampe) Kuntze, Revis. Gen. Pl. 2: 835. 1891. ? Cyclodictyon lindigianum var. acunae Thér., Mem. Soc. Cub. Hist. Nat. “Felipe Poey” 14: 366. 1940, nom. inval. descr. gall. Discussion. Cyclodictyon albicans is the most common Cyclodictyon in the Greater Antilles. Like the other weedy species of the Greater Antilles, C. varians, it has been greatly misunderstood. In Trinidad and Andean South America there appear to be several closely related but distinct species. I have examined two specimens from Trinidad, both different, that resemble C. albicans in the sharply serrate border that is 2 cells wide. However, both have different leaf shapes and, most significantly, both have rough calyptrae. Surely at least one of these represents the Trinidadian C. albatum (Müll. Hal.) Kuntze, although a type specimen, collected by (? Friedrich Wilhelm) Sieber, has not been located. Cyclodictyon albicans is distinguished from other species in the genus by its more or less abruptly tapered, sharply serrate leaf apex. The border, two cells wide, is composed of elongate cells confluent into a long-celled apiculus. The costa is strong, often expanded into a knob at the apex (in lateral leaves), and projects as a prominent spine. The only other Antillean Cyclodictyon with such a strong costa is C. bicolor. In that species, however, the border is 1-2 cells wide, and the cells of the border are shorter than those in C. albicans, with the consequence that the shorter apiculus is composed of shortish cells. Also, C. albicans is very common in the Greater Antilles and C. bicolor is relatively uncommon there. On the other hand, C. bicolor is common in the Lesser Antilles and C. albicans seems to be absent there.
-
Distribution
Range. Reported from Central and northern South America; Bermuda, Cuba, Jamaica, Hispaniola (Haiti and Dominican Republic), Puerto Rico; growing on rotten wood, humus, soil, and limestone, in humid and mesic forests, from near sea level to ca. 1500 m.
South America| Bermuda South America| Cuba South America| Jamaica South America| Dominican Republic South America| Haiti South America| Puerto Rico South America|