Chandonanthus Mitt.
Chandonanthus Mitt. in Hook.f., Handb. N. Zeal. Fl. 750, 753. 1867.
Type: Chandonanthus squarrosus (Hook.) Mitt. ex Schiffn. (≡Jungermannia squarrosa Hook.)
Plants strongly anisophyllous, erect (when terricolous or saxicolous) to pendulous (when epiphytic), yellowish or golden brown, at times reddish brown, vigorous, often 10–20 cm long or more, to 3 mm wide or more. Branching sparingly, the branches typically of Frullania type; half-leaf broadly ovate; first branch underleaf large, asymmetrically bifid + laciniate near base. Stems with paraphyllia present, conspicuous, of diverse form, filiform to lanceolate. Stems rigid, cortex rigid, of 4–5 layers of very thick-walled cells with reduced lumina; medullary cells larger, firm-walled, hyaline. Rhizoids typically present only toward base of leafy shoots, lacking above. Leaves widely spreading, often dorsally assurgent, imbricate, broadly quadrate-ovate, the lamina plicate and undulate, the margins entire except, often, with a few to several cilia or laciniae at the dorsal and ventral bases, (1200)1500–2300 µm wide × (900)1300–1800 µm long, bilobed to ca. 0.5; lobes often abaxially sulcate, broadly acute and with arched margins, at times subapiculate, the tips markedly sharp. Cells with trigones coarse, strongly nodose, often confluent, the cell lumina surrounded mostly by trigones which are separated by narrow, thin-walled places; cells of leaf base longer, the longitudinal walls often each with 1–3 conspicuous nodose intermediate thickenings; surface densely covered with hemispherical, variably sized papillae. Oil-bodies occupying a small volume of cell, hyaline, opaque, dull greyish, (4)5–7 per cell in median sector of lamina, 2–4 per cell toward lobe base, minutely and finely but distinctly granular or moderately papillose, globose to broadly elliptic (often irregularly so), 4.3–6.2 × 2.9–4.3 µm, spherical ones 3.4–4.3 µm in diam. Underleaves large, subquadrate, bifid to ca. 0.55–0.65, the lobes protracted and ciliiform distally, the margins with several cilia/laciniae; lamina margins with several variable cilia/laciniae. Asexual reproduction absent.
Dioecious. Androecia becoming intercalary on leading shoots or elongate Frullania -type branches, subfolious, the bracts similar to vegetative leaves in size, orientation and shape except for basal portion of dorsal lobe which is deeply ventricose, the saccate portions of opposing bracts closely juxtaposed, the bracts rather tightly appressed to bract immediately above; margin of ventral lobe similar to that of leaves; androecia with stem paraphyllia similar to those of sterile portions of shoot, the lobule large for bract size, with margins sharply inflexed to involute to form a pouch, the margin with an acuminate projection, but otherwise with a few sometimes stalked slime papillae; antheridia 2–3 per bract, the stalk 23–26 cells long, biseriate, the jacket-cells scattered; bracteoles large, like underleaves, without antheridia. Gynoecial bracts of innermost series bifid to 0.5–0.65, the apices long-acuminate and becoming ciliiform, the margins ciliate to laciniate; bracteole similar, subequal to bracts or ca. 0.55–0.65 the bract size; paraphyllia copiously developed on the abaxial bases of bracts and bracteole as well as in their axils. Perianth large, ellipsoidal, deeply 6–8-plicate for 0.75–0.9 its length, the mouth with numerous laciniiform-caudate, narrow lobes that may bear 1–2 lateral cilia.
Seta massive. Capsule dehiscing to base into 4–6 valves, the wall fleshy, 90–120 µm thick, of 6–8 layers, the outer layer equal to thickness of 2.3–3 of interior strata; outer layer of cells small, never tiered, subquadrate to short-subrectangular, with one-phase development (the outer layer at times with a two-phase ontogeny at most moderately developed), the radial walls slightly thickened, with red-brown short to often somewhat elongate nodule-like thickenings on longitudinal walls, the transverse walls with thickenings fewer or absent, the outer layer with sporadic semiannular bands; exposed tangential wall in surface view covered with a hyaline, amorphous substance, sometimes wrinkled in appearance, sometimes organized into sharp, conical thickenings lying ± parallel to surface, the substance nearly obliterating detail of nodular thickenings of outer layer; intermediate layers of cells subequal in thickness, with thickenings often feebly tangentially dilated, semiannular bands absent; innermost layer of cells mostly irregularly long-rectangular, the radial walls with moderately thick continuous sheets of red-brown wall material, with semiannular bands, the bands red-brown, common, wide, rather widely spaced, mostly complete, sporadically forked.
Spores 25.4–28.8 µm in diam., red-brown, with coarse, rather close but not crowded papillae and sometimes short-vermiculate ridges. Elaters tortuous, 9.6–13 µm wide, bispiral, the spirals 2.9–3.8 µm wide, loosely wound.
A genus accepted here in the narrow sense, with only one species, which is known only from New Zealand, Tasmania and southeast Australia. The genus was formerly recognized in a broader sense that included Chandonanthus subg. Tetralophozia, which was raised to the generic rank by Schljakov (1976). Tetralophozia (R.M.Schust.) Schljakov has four species and is treated in Schuster (2002b).
Reference: Schuster (2002b).
