Lophozia pumicicola Berggr.
Lophozia pumicicola Berggr., New Zealand Hepat. 21. f. 15. 1898.
Type: New Zealand, North Is., near Lake Taupo, Jan. 1875, Berggren (G!).
Type: New Zealand, South Is., Arthur’s Pass, June 1942, H. M. Hodgson & MacDonald (MPN!).
Plants brittle, prostrate and firmly adhering to substrate, pale, whitish green, often reddish brown, the lobes often appearing bleached distally, the shoots minute, to 1 mm wide, 3 mm long, the shoots at times with only a few leaves. Stems firm, slender for shoot size, with cortical cells poorly differentiated, somewhat thick-walled, the exposed wall at times rather distinctly so, subequal to the medullary cells, a few ventral cells with mycorrhizal hyphae; medullary cells undifferentiated, ± uniform, with mycorrhizal hyphae present, at times in nearly all cells, the medulla becoming brownish with age (even when cortex is subpellucid). Rhizoids rather dense (even near shoot apices), scattered on ventral surface of stem, at times long for shoot size. Branches sparing, the shoots often simple, the branches of lateral-intercalary type. Leaves vertical, strongly dorsally assurgent and with much of leaf elevated above dorsal surface of stem, regularly homomallous, often closely imbricate, the insertion strongly succubous; leaves strongly concave, ovate, often rather broadly so, longer than broad or as wide as long, conspicuously narrowed in the apex, bifid to 0.25–0.35; lobes in flattened leaves often rather closely juxtaposed (the lobes often less than a third the maximal leaf width apart), ± parallel and non-divergent, acute, often apiculate, terminating in a single cell or a uniseriate row of 2 cells, the tip cell isodiametric grading up to 2× longer than wide, the lobes entire; sinus often sharply V-shaped; lamina margins rather evenly arched but the ventral margin a little dilated in basal half, the margins entire. Cells with walls thin, trigones medium and straight-sided, occasionally minute, the median cells 18–23 µm wide × 18–24 µm long (type) to 19–26 µm wide × 22–28 µm long; surface distinctly striate-papillose. Oil-bodies (Schuster, 2002a) 6–13 per cell, coarsely papillose. Underleaves typically absent, at times present, minute, linear to subulate. Asexual reproduction lacking.
Paroecious. ♂ Bracts in 1–2 pairs below the ♀ bracts; antheridia 1 per bract, the stalk uniseriate; paraphyses sometimes present among the antheridia, small, laciniiform. Gynoecia with bracts free from one another or distinctly connate dorsally, asymmetrically ovate, with apex and margins scarious, 2–3-lobed, the lobes entire or with 1–2 teeth; lamina margins entire or with 1–2 teeth below the middle; bracteoles connate on one or both sides for 0.25–0.4, at times connate on both sides and bracts also connate dorsally for ± the same distance, together forming a low, ensheathing tube, the bracteole small compared to bracts, undivided and subulate or short-bifid. Perianth relatively short, elliptic in outline, plicate distally, slightly contracted toward the mouth, the apex scarious, formed of guttulate, often distinctly hyaline cells, the mouth lobulate, the lobules irregularly dentate by teeth of 1–3, thick-walled cells.
Sporophyte not seen.
Distribution and Ecology : Endemic to New Zealand: South Island (ca. 700–920 m), North Island (690–ca. 1200 m). Known from several scattered stations in New Zealand, including the central volcanic region of the North Island. The type occurred “growing on dry ground of gravel of pumice-stone amongst the common fern, Pteris esculenta ” (Berggren, 1898, p. 21). In Tongariro Natl. Park at Mangatepopo Stream (below Soda Springs) on a thick soil layer over a boulder under low shrubby cover in an area of alpine vegetation with scattered frequent rocky outcrops. Schuster (2002a, fig. 300, p. 246) illustrated a plant from “frost flats near Minganui” (Taho Flats near Otupaka Stream, SW of Minginui). This site is an open, low area with scattered Leptospermum scoparium and Dracophyllum subulatum with abundant Cladia retipora. The species occurs there in a mossfield of Polytrichum juniperinum, Campylopus clavatus, Chrysoblastella chilensis, Ditrichum punctulatum and Cladia aggregata. Collections made by K. W. Allison in the 1930s suggest that the species was once common in the Rotorua–Kaingaroa area in similar situations. In the South Island (Mt. Richmond Forest Park, Red Hills, track to Maitland Hut, Marlborough, ca. 700–920 m) over bare lichen-moss covered soil in rather open Leptospermum scoparium scrub in a serpentine area. Also beside the road north of Te Anau, Fiordland where among mosses in L. scoparium scrub and also at Arthur’s Pass (type of Lophozia innominata). The ecology of the species needs further investigation based on the study of more collections, but the species is not an “ecological specialist, occurring apparently only on volcanic ash and known only from the central volcanic region of the North Island of New Zealand” as stated by Schuster (2002a, p. 247).
Comments : Lophozia pumicicola is a distinctive species. Plants are minute, with regularly homomallous, vertical, strongly dorsally assurgent, leaves with much of the leaf elevated above the dorsal surface of the stem. The leaves are strongly succubously inserted, often notably closely imbricate, strongly concave, bifid to 0.25–0.35, often rather broadly ovate and markedly narrowed at the apex, with the lobes often closely juxtaposed. Plants are paroecious, do not produce gemmae and underleaves are consistently lacking on sterile shoots. Also, the stem cortical cells are poorly differentiated, subequal to the medullary cells, which are undifferentiated, ± uniform and with mycorrhizal hyphae present.
The type of Lophozia innominata differs in some respects from the protologue of the species (Hodgson, 1946). Median leaf cells are 24–26 µm wide × 23–26 µm long and not “33–40” µm as stated by Hodgson (1946). Also, Hodgson (1946) stated the leaves are bifid or very rarely trifid. Sterile shoots of the type are consistently bilobed, but ♂ branches may have a sporadically trilobed leaf. The leaf surface is striate-papillose, although less conspicuously so than in other populations of the species, and trigones are medium and straight-sided. Hodgson (1946, p. 69) stated that the trigones are “parvis vel majusculis.”
