Bazzania Gray
Bazzania Gray, Nat. Arr. Brit. Pl. 1: 704, 775. 1821, “Bazzanius,” orth. cons.
Type: Bazzania trilobata (L.) Gray (≡Jungermannia trilobata L.)
Plants strongly anisophyllous (except Bazzania involuta), typically firm, deep green to olive-green to yellow- or chestnut-brown, dull to highly nitid or (B. tayloriana) glaucous, milky and opaque, the shoots medium to robust in size, to 6 mm wide. Branching frequent, usually freely and repeatedly pseudo-dichotomous and never pinnate or (B. involuta) branching monopodial, the branches of Frullania type, normally originating from only one side of axis, subequal to main axis in vigor and with the main axis losing its dominance, branch half-leaf undivided, positioned in the fork of each “dichotomy”; first branch underleaf variable, asymmetrically or symmetrically 2–3(4)-lobed, rarely undivided, free or at times connate with a normal stem underleaf. Ventral branches all intercalary, occasional to frequent, often long and whip-like, stoloniform, geotropic, with scale-like leaves; ventral-intercalary leafy branches occasional to frequent. Stems rigid, with cortical cells often larger than the medullary, thick-walled, often ± evenly so. Rhizoids frequently at bases of reduced underleaves and leaves of geotropic stoloniform branches, less commonly from bases of underleaves on normal leafy shoots. Leaves alternate or subopposite (in ventral view), plane to moderately convex (the lobes often ± deflexed), widely spreading, the insertion distinctly incubous and extending to stem midline dorsally, the leaves typically ± asymmetrically ovate to falcate-rectangular, the dorsal margin commonly more arched and ampliate than the ventral; apex 2- or (in ours) 3-dentate (teeth sometimes obscure or almost lacking on weak shoots), at times with accessory teeth; dorsal margin (in ours) strongly arched, ampliate, at times cordate at base, entire or (rarely) denticulate; ventral margin typically ± straight or at times somewhat incurved, sometimes auriculate at base, entire or (rarely) denticulate (ciliate at the base in some extraterritorial species). Cells with walls slightly to distinctly thickened (especially in subapical sector of leaf), with trigones small to bulging and nodulose, the areolation ± uniform and without a vitta or the leaves subvittate (with a broad, indistinct band of enlarged cells in the median longitudinal portion of leaf), or the leaves distinctly vittate with several rows of sharply differentiated cells; surface smooth or papillose or (B. tayloriana) glaucous. Oil-bodies large for cell size, 2–6 per cell, homogeneous or at times few-segmented. Underleaves usually no more than 0.35–0.45× leaf area, or sometimes approaching the leaves in size in some species, free or connate with the leaves on one or both sides, variable, large and widely spreading to closely appressed to the stem and inconspicuous, ± quadrate to orbicular to transversely rectangular to reniform, the apex distinctly and regularly 4-lobed or truncate to rounded-truncate and variously lobulate, toothed or ragged, often with some or all of the cells decolorate and forming a hyaline distal sector, the base at times cordate. Asexual reproduction, when present, by caducous leaves and underleaves, also (B. nova) by regeneration from leaves.
Dioecious but often sterile, rarely with sporophytes. Androecia on short, ventral-intercalary branches from lower sectors of leading shoots and from both ventral and lateral sides of stoloniform branches, the androecia inconspicuous, tightly spicate; bracts concave to ventricose-cucullate to canaliculate, the apices truncate and entire to bidentate or bilobed; antheridia 1–2 per bract, the stalk biseriate; bracteoles smaller than bracts. Gynoecia on abbreviated ventral-intercalary branches issuing from main stem; bracts of innermost series largest, erect and closely ensheathing the perianth, the apices 2–4-lobed, the lamina margins usually variously crenate to dentate (in ours) or ciliate or laciniate-ciliate; bracteole similar in size and form. Perianth subfusiform, terete below, trigonous and plicate above, gradually narrowed toward the usually contracted mouth; the mouth denticulate-dentate to subciliate; perianth usually multistratose below.
Seta usually with 10–16 outer cell rows and a central core of numerous, much smaller cells. Capsule ovoid to ovoid-oblong to long-ellipsoidal, the walls (3)4–6-stratose; outer layer of cells with two-phase development, the longitudinal walls with coarse, nodular thickenings that are sometimes confluent and then at least locally sheet-like alternating with walls that are devoid of thickenings (or are sporadically locally thickened), the transverse walls devoid of thickenings or sporadically have an isolated swelling; innermost layer of cells commonly with numerous semiannular bands.
Spores brown, with papillae and simple or furcate vermiculate markings, 1–1.25 to 2–3× the elater diam. Elaters rather rigid, nontortuous or at most feebly tortuous, long and slender, bispiral.
Key to Species
A large genus of over 100 species worldwide, with particularly strong representation in tropical montane regions. For example, Fulford (1963b) records 54 species from Neotropical regions (all but Bazzania skottsbergii have stations in the tropics), but Gradstein et al. (2001) stated “probably no more than 40 species in tropical America.” Grolle and Piippo (1984) record 53 species for New Guinea. Fulford (1946, 1959, 1963b) published useful revisions of the Neotropical and southern South American species. Two species occur in southern South America, B. peruviana (Nees) Trevis. and the pan-temperate B. nitida (F.Weber) Grolle (see Engel, 1978). Bazzania chilensis (Steph.) Fulford (see Fulford, 1963b, p. 125) is poorly known and needs further evaluation, and B. skottsbergii (Steph.) Fulford, while recognized by Fulford (1963b), is a synonym of B. peruviana (see Grolle, 1964a; Engel, 1978). Arnell (1963) included four species from South Africa, including B. adnexa, a species also present in our area. Nine species occur in New Zealand.
We do not recognize subgenera within the genus, and with regard to subgeneric categories, recognize only the section level, following arguments put forth by Schuster (1969c, 2000a).
References: Engel (2006b); Engel and Merrill (1994); Engel and Schuster (1988); Hodgson (1954; rev.); Schuster (2000a).
Note : After the manuscript was prepared for publication Meagher (2003) reported Bazzania accreta (Lehm. & Lindenb.) Trevis. in New Zealand; the species was heretofore known only for Australia.
