Lepidopilum tortifolium Mitt.

Authority

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

Family

Pilotrichaceae

Scientific Name

Lepidopilum tortifolium Mitt.

Description

Species Description - Plants medium-sized to fairly robust, in ± lustrous, green to brownish, mostly lax mats. Stems creeping or trailing, to ca. 6 cm long, sparsely branched, obscurely complanate-foliate; in crosssection with a hyalodermis of medium-sized cells over 2-3 rows of medium-sized thick-walled colored cells surrounding large, thin-walled cells, central strand none; axillary hairs 2-celled, with a short brown basal cell and an elongate hyaline distal cell. Leaves contorted when dry, sometimes also when moist, lateral leaves wide-spreading dry or moist, oblong to oblong-ovate, (1.8-)2.2-2.7 mm long, asymmetric, dorsal leaves erect, broadly oblong to ovate to broadly ovate, slightly shorter than lateral leaves, ± symmetric, all usually abruptly short-acuminate or cuspidate; margins bordered by ca. 4 rows of elongate cells near midleaf, often only ca. 2 rows at apex and with shorter cells, at base becoming ± indistinct due to elongation of adjacent laminal cells, serrulate to serrate above, entire below, plane; costa double, ending the leaf length, in lateral leaves one fork approaching margin, tapering distally, not projecting at apex; cells in upper part of leaf mostly hexagonal, 1-2:1, 28-33 µm wide, thick-walled, becoming somewhat longer at apex and extending into the acumen, becoming rectangular toward insertion, 3-4:1, and obscuring border; alar cells not differentiated. Asexual propagula not seen. Dioicous. [Sporophytes not known from the West Indies; description from the South American type.] Perichaetia small, inconspicuous, in leaf axils on primary branches; leaves few, pale, narrowly triangular, 1.1-1.4 mm long, gradually or ± abruptly acuminate; margins bordered by 1-2 row of elongate, narrow cells, entire, plane; costa none; cells long-hexagonal above, becoming long-rectangular toward the insertion, thin-walled. Setae elongate, papillose throughout, dark-red, ca. 12 mm long; capsules erect, cylindric, symmetric, ca. 2 mm long; exothecial cells rectangular, thick-walled, not collenchymatous; annulus of a single row of subquadrate cells, usually falling with the operculum; operculum high-conic to conic-rostrate; exostome teeth recurved when dry, strongly bordered, densely and finely papillose throughout, on the front surface pale, reddish and somewhat trabeculate at back; endostome yellowish, densely and finely papillose throughout, with a low basal membrane, segments erect, slightly or not keeled, not perforate, cilia none. Spores spherical, finely papillose, ca. 14 µm diam. Calyptrae cucullate, covering operculum and upper 1/2 of urn, not plicate, irregularly lobed at base, ornamented with multiseriate, rather short ramenta, slightly roughened at apex.

Discussion

2. Lepidopilum tortifolium Mitt., J. Linn. Soc., Bot. 12. 374. 1869. Plate 13, figures 1-7 Hookeria riparia Mitt., J. Linn. Soc., Bot. 12: 345. 1869; Cyclodictyon riparium (Mitt.) Kuntze, Revis. Gen. Pl. 2: 835. 1891. Discussion. Lepidopilum tortifolium is characterized by contorted leaves that are well bordered, especially at midleaf. The upper cells are hexagonal and thin-walled and extend into the acumen; below they become elongated and more or less obscure the border. The seta is fairly long for the genus, ca. 12 mm, and papillose throughout. Lepidopilum tortifolium is unlikely to be mistaken for any other Lepidopilum. The only confusion might be with L. polytrichoides because of the contorted, bordered leaves with short upper cells. In fact, the two species are very different. Lepidopilum polytrichoides is a much bigger plant with sharply serrate leaves and frequently with sporophytes. Although occurring in humid habitats, L. polytrichoides almost always grows on twigs or tree trunks, whereas L. tortifolium usually grows on wet rocks along streams. Rather, L. tortifolium is most likely to be confused with Cyclodictyon subtortifolium. Both grow in similar habitats and have a similar aspect. However, in C. subtortifolium the leaf cells do not extend into the leaf apex and are much smaller, only 11-15 µm wide rather than 28-33 µm as in L. tortifolium. Also, in C. subtortifolium the border remains distinct even at the base of the leaf. The epithets in some of the aquatic hookerioid mosses have been confused due to taxonomic misinterpretation. Cyclodictyon ripcirium. long considered a synonym of C. roridum, is rather a synonym of L. tortifolium. In fact, material usually named C. roridum should actually be called L. tortifolium. Cyclodictyon roridum is the oldest name for C capillatum. Cyclodictyon roridum might be confused with L. tortifolium but it usually does not have contorted leaves and the serrate leaf apex is much longer.

Distribution

Range. Mexico and Central America, Andean South America, Brazil; Jamaica, Hispaniola (Dominican Republic), Puerto Rico; growing on wet rocks in streams, at moderate elevations, ca. 800-1500 m.

Mexico North America| Central America| Venezuela South America| Colombia South America| Ecuador South America| Peru South America| Brazil South America| Jamaica South America| Dominican Republic South America| Puerto Rico South America|