Cephalozia pachygyna R.M.Schust.
Cephalozia pachygyna R.M.Schust., Beih. Nova Hedwigia 119: 25, 29. f. 220, 221. 2002, nom. nud.
Cephalozia pachygyna R.M.Schust. ex J.J.Engel, Novon 17: 313. 2007.
Holotype: New Zealand, South Is., Fiordland, Schuster 84-138 (herb. Schuster).
Plants soft, loosely creeping, whitish green, no secondary pigments seen (plants observed only in non-exposed niches). Branches of Frullania type, the half-leaf ovate to sublanceolate; ventral-intercalary type branches common. Stems with cortical cells in 12–13 rows, firm-walled, not sharply differentiated, slightly to at most moderately larger than those of the medulla; medullary cells firm-walled. Rhizoids scattered, hyaline. Leaves vertically oriented, strongly dorsally assurgent, variably spreading, suberect to obliquely so, distant to contiguous, succubously to subtransversely oriented, the insertion weakly to strongly succubous, extending virtually to stem midline dorsally (the basal cell of leaf impinges on stem midline), the leaves concave, ovate (at times narrowly so), uniformly bilobed to 0.4–0.5; lobes incurved, at times abruptly so and the lobe tips then claw-like, moderately to narrowly acute, the apices terminating in a single cell or a uniseriate row of 2 cells at most slightly longer than wide, the lobes 8–10 cells wide at base; lamina 12–14 cells wide. Gemmae lacking. Underleaves absent.
Autoecious. Androecia on slender ventral-intercalary branches. Gynoecia on leading shoots; bracts much larger than leaves, narrowly elliptic-ovate to sublinear, 2-lobed. Perianth ca. 0.5 exserted, narrowly elliptic, terete below, trigonous distally, weakly plicate above, the mouth crenulate to crenate-feebly denticulate; perianth base 4–6-stratose.
Capsule ellipsoidal, the wall with outer layer of cells subquadrate to narrowly short-rectangular, with two-phase ontogeny ill-defined, the longitudinal walls with nodular to spur-like thickenings alternating with walls either lacking thickenings or with sinuous thickenings; inner wall with semiannular bands, the bands narrow, at times incomplete.
Spores and elaters not seen.
Distribution and Ecology : Endemic to New Zealand: South Island (1650 m).
Known only from a few collections. Occurring deep in a protected pocket of an outcrop at 1650 m in the alpine zone (area immediately below summit of Avalanche Peak, Scotts Track, Arthur’s Pass Natl. Park). The type is from Fiordland.
Comments : The following combination of features are distinctive for the species. The leaf insertion extends to the stem midline dorsally, with leaf lobes 8–10 cells wide at the base and terminating in a single cell or a uniseriate row of 2 at most weakly elongated cells. Underleaves are completely lacking. Stem anatomy should be examined: Cortical cells are in 12–13 rows of firm-walled cells that are only slightly larger than medullary cells. The perianth base is fleshy, being 4–6-stratose, and the perianth mouth is crenulate, with only weakly elongated cells (at most 2:1). Plants develop brownish to purplish pigmentation in exposed sites, and asexual reproduction is lacking. The type is illustrated in Schuster (2002a, figs. 220, 221).
