Drucella E.A.Hodgs.
Drucella E.A.Hodgs., Trans. Roy. Soc. New Zealand, Bot. 2: 45. 1962.
Type: Drucella integristipula (Steph.) E.A.Hodgs. (≡Lepidozia integristipula Steph.)
Plants strongly anisophyllous, light green to whitish green, weakly chlorophyllose and devoid of wall pigments, nitid, to 0.45 mm wide. Plants with an extensive system of basal, creeping, plagiotropic, small-leaved, often microphyllous, strongly elongated, occasionally branched rhizomatous or stoloniform axes from which arise ascending to erect, often arched, simple or sporadically branched leafy shoots of limited length. Branching irregular, uniformly intercalary, the branches mostly lateral, exceptionally ventral. Stem rigid and wiry, the cortical cells in surface view strongly elongated, ± tiered, the longitudinal walls very thick, the transverse ones thin, in cross section in 6–10 rows; medulla of 5–9 rows of rather thick-walled cells of ± similar diameter to the cortical cells. Rhizoids occasional, the tips often swollen, at underleaf bases of older sectors of shoots, also from bases of leaves and underleaves of rhizomes or stolons. Leaves contiguous to weakly imbricate, stiffly and widely spreading, 160–250 µm wide at the lobe apices, 100 µm wide at the leaf base, 270–325 µm long, separated by 1–3 cortical cells on either side, the insertion clearly incubous, not reaching stem midline dorsally and delimiting a leaf-free strip of 2 rows of cortical cells; leaves asymmetrically cuneate to narrowly obtrapezoidal, rather narrowed to the insertion, (2)3-fid to 0.5–0.75. Lobes usually unequal, entire, the dorsal lobe linear-lanceolate, 2–3(4) cells wide at base, terminating in a uniseriate row of 2–4 moderately elongated cells, the middle lobe similar to the dorsal or a little smaller, the ventral lobe usually smaller, often only 1–3-celled and at times ending in a slime papilla. Disc mostly 2–3(4) cells high, (5)6 cells wide at the base. Cells of disc cells pellucid, equally very thick-walled and without trigones, the middle lamella conspicuous, the median cells 20–25 µm wide × 30–35 µm long; surface smooth. Oil-bodies absent or occasionally 1 or 2 per cell, spherical, moderately but faintly granular, ca. 5 µm in diam., breaking up rapidly to oil-droplets that are homogeneous, small, 1.8–2.3 µm in diam. Chloroplasts few. Underleaves inserted on 2–3 rows of stem cells, narrower than stem and leaving the stem broadly exposed, distant, small, spreading to squarrose, ± obtrapezoid-quadrate, 2–3-lobed, the lobes often unequal, consisting of 1–2 cells, terminating in a slime papilla; the disc 1–2.5 cells high and 3 cells wide. Asexual reproduction absent.
Dioecious. Androecia typically on short ventral-intercalary branches, rarely on lateral-intercalary branches; bracts slightly larger than vegetative leaves, strongly concave, bifid to 0.5–0.7; antheridia 1 per bract, the stalk uniseriate. Gynoecia typically on short ventral-intercalary branches, exceptionally on short lateral-intercalary branches; bracts in 2–3 series, appressed to perianth, (2)3–5-fid to 0.5–0.7, the lobes 2–4 cells wide at base, terminating in a uniseriate row of 5–7 cells, the lobes with a few teeth below, the distal sector of lobes ciliiform; bracteoles similar to bracts but somewhat smaller and sparingly armed. Perianth ovoid-cylindrical, the mouth wide, lobulate-ciliate, the cilia terminating in a uniseriate row of 4–8 elongated cells, with accessory teeth below; perianth unistratose throughout and with cell walls thinner than those of leaf cells.
Seta with 8 rows of outer cells surrounding an inner core of 14–16 much smaller cells. Capsule short-ovoid, small, the valves only 140–145 × 315–330 µm, the wall 14–15 µm thick, bistratose, the outer layer somewhat thicker than the inner; outer layer of cells distinctly tiered, comprised of only 6–7 tiers (the large basal cells at valve base excepted), the cells long-rectangular, the development of the outer layer not fixed and of two types: a) one with two-phase development, the longitudinal walls with pale magenta, well-defined, sheet-like, continuous thickenings + nodule-like thickenings (lending a sinuous appearance) alternating with walls that are devoid of thickenings (or with a very few, sporadic, local, non-pigmented, nodular swellings), the transverse walls devoid of thickenings; and b) the other type with one-phase development, all longitudinal walls with thickened continuous sheets of pigmented material and (fide Boesen, 1982) with semiannular bands common; innermost layer of cells markedly long and narrowly rectangular, the longitudinal walls with thick continuous sheets of material, with semiannular bands common or with complete, well-developed bands present but less frequent, the longitudinal walls then with nodular thickenings that variously extend onto the exposed tangential wall as feeble spurs or weak, faintly pigmented incomplete or complete semiannular bands.
Spores 8.6–9.6 to 11–13.2 µm in diam., reddish brown or yellow-brown, finely reticulate. Elaters rigid, 8.2–9.6 to 11–16 µm wide, slightly tapered to tips, bispiral, the spirals 2.4–2.9 µm wide.
The genus is monotypic and known only from New Zealand, Tasmania and southeast Australia.
References: Boesen (1982); Hodgson (1962b); Schuster (1980a, 2000a).
