BFNA Title: Dacryophyllum
DACRYOPHYLLUM - Hypnaceae
XXX. DACRYOPHYLLUM Ireland, Novon 14: 70. 2004. * [Greek dakryo-, to shed tears or weep, and phyllon, leaf, alluding to the basal leaf cells having proximal prorulae with the appearance of tears]
Robert R. Ireland
Plants small, in thin mats, complanate-foliate, glossy, light- to yellow-green. Stems prostrate, relatively short and narrow, simple or sparingly and irregularly branched, cortical cells moderately small, thick-walled, in 2--3 rows, central cells large, thin-walled, central strand lacking; rhizoids few, smooth, on ventral surface of stems and branches, single or in clusters just proximal to leaf insertion; axillary hairs ca. 108 /um, mainly in axils of distal leaves near apical bud, with 1 short, brown basal cell and 1--2 elongate, hyaline distal cells; pseudoparaphyllia narrowly foliose, 2--4 cells wide, margins serrulate to toothed, sometimes with single-celled, large teeth, usually mixed with some entire filamentous pseudoparaphyllia, 3--6 cells in length, branch primordium not evident among pseudoparaphyllia. Stem and branch leaves similar, stiff, appressed-imbricate, flat, smooth, asymmetric, oblong-lanceolate, acute to obtuse, falcate, margins plane, serrulate, becoming serrate at leaf base, serrations often formed by two abutting basal cell, broadly incurved on one side at base, nondecurrent; costa lacking or indistinctly double; cells thin to moderately thick-walled, linear-flexuose to rhomboidal, especially near leaf apex, smooth or often with minute prorulae on abaxial surface at distal and proximal ends, prorulae sometimes more prominent on basal cells, with walls not pitted; basal row of cells at stem insertion each with a large prorula at proximal end on abaxial surface; alar regions differentiated, 1--4 rows of quadrate to rectangular cells with 2--7 cells in marginal row. Specialized asexual reproduction lacking. Sexual condition unknown.
Species 1; western North America.
Dacryophyllum is endemic to California, occurring in the west-central part of the state in terrestrial habitats on calcareous substrates in Coast Redwood forests.
SELECTED REFERENCES. Ireland, R. R. 2004. Dacryophyllum falcifolium, a new North American genus and species (Musci: Hypnaceae) from California. Novon 14: 70--74. Kellman, K. and J. R. Shevock. 2006. Notes on Dacryophyllum falcifolium Ireland. Evansia 23: 36--39. Norris, D. H. and J. R. Shevock. 2004. Contributions toward a bryoflora of California: I. A specimen-based catalogue of mosses. Madroño 51: 1--131. Norris, D. H. and J. R. Shevock. 2004. Contributions toward a bryoflora of California: II. A key to the mosses. Madroño 51: 133--269.
1. Dacryophyllum falcifolium Ireland, Novon 14: 70. 2004
Stems to 1.5 cm, 0.8--1 mm wide. Leaves 0.3--0.5 × 0.1--0.2 mm; median cells 32--45 × 4--5 /um; apical cells 10--28 x 5--7 /um; alar cells 8--19 x 6--7 /um. Sexual condition unknown, neither antheridia nor archegonia seen.
Vertical surfaces of shaded, calcareous rock cliffs and rock outcrops in redwood forests; 50--240 m; Calif. (Monterey and Santa Cruz counties).
Dacryophyllum falcifolium is macroscopically distinguished by small-sized plants, the stems prostrate, only ca. 1.5 cm; small complanate-foliate, glossy leaves that are light- to yellow-green; usually strongly falcate leaves with acute to obtuse apices; and serrulate to serrate leaf margins. Microscopically, it is recognized by its costa, which is lacking or indistinct or short and double; alar region that has abutting cells along the margins forming serrations; prorulae on the abaxial surface of the leaf cells often at both ends; basal row of leaf cells at the stem juncture where there are large prorulae at the proximal ends on the adaxial surface; and pseudoparaphyllia that are foliose with serrulate to toothed on the margins, sometimes mixed with entire filamentous ones.
The genus Dacryophyllum appears most closely related to Taxiphyllum, another genus in the Hypnaceae that occurs on calcareous substrates, but it differs from all species in that genus primarily because they lack the large prorulae on the abaxial surface at the proximal ends of the basal cells at the stem insertion. The genus also differs by filamentous, entire pseudoparaphyllia occuring in clusters mixed with foliose, serrulate to toothed ones without an evident branch primordium. In Taxiphyllum, on the other hand, the branch primordia are nearly always evident and the species only have foliose pseudoparaphyllia. Although no specialized asexual reproductive bodies are known for Dacryophyllum falcifolium, K. Kellman and J. R. Shevock (2006) have observed that small branches break off the plants and the thin mats of the species are easily removed from the substrate. They therefore believe that these branches may be easily moved from place to place by small animals or strong winds, as asexual reproduction.