Kurzia helophila R.M.Schust.
Plants anisophyllous, stiff and wire-like, erect or suberect, densely caespitose, turf-forming, golden brown to dark brownish or fuscous (new growth often greenish), freely branched, the shoots to 5 mm wide, including branches. Branching mostly terminal (Frullania and Microlepidozia type), distantly and sympodially branched (rarely 1- or 2-pinnate), the branches dorsally ascending, typically overtopping as new leading shoots, not becoming microphyllous; branch half-leaf linear, 2-lobed to 0.4–0.6; first underleaf of Frullania -type branch 3–4-lobed, inserted on ventral-lateral side of branch base and aligned with underleaves of branch; branch leaves 3–4-lobed. Ventral-intercalary branches rather common, stoloniform, or ascending and giving rise to new shoots. Stem epidermal cells in 10–12(16) rows, weakly to moderately thick-walled (surface view), brownish, larger than the leptodermous or weakly incrassate, usually hyaline medullary cells; cortical cells 5–9 intervening between successive leaves on each side of stem. Leaves distant to crowded on the same shoot, hand-like, often distinctly cupped, the disc obliquely spreading, the lobes incurved, the insertion transverse to weakly incubous; leaves (180)300–400(420) µm long and wide, variable in shape, symmetric to somewhat asymmetric, longer than broad, ± equally (3)4(5)-lobed to 0.5–0.6 (median sinus), often bisbifid and then lobes in pairs. Lobes attenuate, (3)4–8 cells broad at base, entire, ending in a single cell or a uniseriate row of 2–3 cells. Disc symmetric to weakly asymmetric, (5)7–10(12) cells high at median sinus, unarmed, the margins entire. Cells of leaf disc with walls brownish, moderately and evenly thickened, the cells ca. 16–18 × 17–24 µm; lobe cells quadrate, ± isodiametric; surface smooth. Underleaves ca. 0.4–0.5 the area of leaves, concave, symmetric or asymmetric, 4-lobed to 0.45–0.8 (typically 1–2[3] lobes somewhat shorter, ending in slime papillae), sometimes weakly bisbifid, the normal lobes attenuate; disc 5 cells high at median sinus; disc margins entire. Asexual reproduction absent.
Androecia rather elongated, normally determinate, compactly spicate, on ventral-intercalary or terminal-lateral branches, the ♂ branch rarely with limited proliferation vegetatively distally (the androecium then basal on a rather short branch); bracts in 4–7 pairs, ventricose-cucullate, 2–3-lobed to ca. 0.3, the lobes acute, at times apiculate, the dorsal margin sparingly crenate, the bract cells leptodermous; antheridia 1 per bract, the stalk biseriate. Gynoecia (only young known) on short to weakly elongated ventral-intercalary branches; bracts shallowly lobed at summit, the lobes sharp to blunt, entire to weakly few-dentate. Perianth (immature) shallowly lobulate at mouth, the lobes 2–6 cells broad at base, drawn out into acuminate apices usually formed of 1–2 strongly elongated cells (4–7:1), the perianth at base 3–4-stratose, becoming unistratose distally and formed of narrow, elongated cells.
Sporophyte not seen.
Key to Varieties
Comments : Kurzia helophila differs from all other New Zealand species of the genus in the smooth surface, the tall disc (typically 7–9 or even 10–11 cells high) and the complete absence of armature on both leaf and underleaf margins. The leaves are lax, concave and frequently bisbifid, the median sinus noticeably deeper than the others. Plants of K. helophila are usually sparingly branched, the branches often overtopping the main shoot. The color of the plants is fuscous to a clear brown and may be used to distinguish the species when growing together with other Kurzia species. The leaves are very variable in shape, but there is never any indication of teeth of disc or of lobes.
The species tends to grow erect, with ascending branches. At least some phenotypes regularly produce what can only be described as slender roots: the main axis, usually 105–115 µm wide and with cell walls fuscous and thickened, gives rise to very slender, ventral-intercalary geotropic axes that are pale brown or colorless and often only 32–45 µm in diam. These have narrowly rectangular, relatively thin-walled cortical cells. We have not seen such striking dimorphism between rather rigid stems (and ascending branches) and slender, flagelliform axes in any other Kurzia species; their microphyllous branches are never as slender. The erect main axes, mostly 10–15 mm high, may bear “roots” some 4–6 mm long from lower sections of main axes, and such roots appear never to ramify. The leafy shoot is pinnulate with leafy branches that often taper distally and become small-leaved; such branch apices never become nearly as slender as the “roots.”
Other extremes (e.g., the type of var. flaccida) seem to wholly lack the slender geotropic microphyllous axes.
The two varieties of the species may be distinguished as follows:
