Andrewsianthus R.M.Schust.
Andrewsianthus R.M.Schust., Rev. Bryol. Lichénol. 30: 66. 1961.
Cephalolobus R.M.Schust., Rev. Bryol. Lichénol. 34: 244. 1966.
Type: Andrewsianthus puniceus (Nees) R.M.Schust. ex Grolle (≡Jungermannia punicea Nees)
Plants usually loosely procumbent, golden brown to red-brown, the leafy shoots typically becoming attenuate and flagelliform, the flagella either plagiotropic and remaining on the substrate surface ( subg. Cephalolobus) or abruptly geotropic and penetrating the substrate ( subg. Andrewsianthus); other geotropic flagelliform axes arising from normal-leaved shoot sectors usually lacking, and the leafy shoots not arising from a system of creeping stoloniform axes. Branches lateral-intercalary, arising from near the juncture of the leafy shoot sectors and attenuated flagella, originating either from the leaf axil, thus lateral in position ( subg. Cephalolobus) or from dorsal end of leaf axil, and arching up and away from the parent stem ( subg. Andrewsianthus); ventral-intercalary branches present in a few species (e.g., A. planifolius); Frullania- type branches absent (except in A. achrous and subg. Pseudotritomaria). Stems rigid, wiry, narrow for shoot size, the cortex usually well developed, in 1–2 layers of thick-walled cells, the cortex and medulla without mycorrhizal infection. Rhizoids few or lacking on normal-leaved shoot sectors, but sporadic to frequent on flagelliform sectors. Leaves with insertion subtransverse to succubous, the insertion extending to but not beyond the dorsal stem midline, the leaves usually bilobed, unlobed in a few species, trilobed in subg. Pseudotritomaria but very rarely elsewhere, the lobes entire, the lamina margins entire or with a few slime papillae near dorsal base. Cells with trigones distinct, at times moderately nodose, the cells of moderate size (ca. 20–30 µm in diam. at leaf middle); surface striolate-papillose. Oil-bodies usually 2–5 per cell, finely granular, medium to rather large. Underleaves lacking or vestigial (ventral merophytes narrow), lanceolate or (often) consisting of 1–3 stalked slime papillae. Asexual reproduction lacking (except with gemmae only in A. kilimanjaricus).
Dioecious. Androecia terminal but becoming intercalary on leading leafy axes, laxly spicate, the bracts spreading, with 1(2) sharp teeth at dorsal base; antheridia 1(2) per bract, the stalk uniseriate. Gynoecia terminal on leading leafy axes, the bracts in 1–3 gradually larger series, those of innermost series usually bifid, the lobe and lamina margins variously dentate to laciniate, less often entire; bracteole distinct, at times strongly connate on 1 side, usually (at times asymmetrically) bilobed (undivided in Andrewsianthus australis), armed like bracts or entire. Perianth terete below, pluriplicate distally, contracted to the mouth, the mouth lobulate, the lobules ciliate-laciniate to ciliate, with a uniseriate row of up to 7 cells.
Seta massive and of many cells or of 12+4 type. Capsule ellipsoidal, the wall 3(4)-stratose; outer layer of cells with strong nodular thickenings; inner layer of cells with semiannular bands, the bands mostly complete, at times branching and anastomosing to form local fenestrae.
Spores baculate, the bacula cylindrical, somewhat longer than wide and truncate at the apex (Andrewsianthus australis) or minutely spinulose. Elaters 2(3)-spiral, the spore:elater diam. ratio ca. 4:1.
Key to Andrewsianthus and similar-appearing genera
Key to Species
A genus of ca. 25 species found chiefly in the Asian tropics and the southern temperate regions. Schuster (2002a) recognized three subgenera:
1) subg. Cephalolobus (R.M.Schust.) R.M.Schust. is strictly south temperate; Andrewsianthus sphenoloboides (R.M.Schust.) R.M.Schust. ex J.J.Engel and A. scabrellus (C.Massal.) R.M.Schust. ex J.J.Engel (Engel, 2007) occur in southern South America and two species occur in New Zealand.
2) subg. Andrewsianthus has several Austral species. Andrewsianthus australis J.J.Engel occurs in southern Chile and the Falkland Islands (Engel, 1972, 1978, 1990a) and A. planifolius J.J.Engel is endemic to the Falkland Islands (Engel, 1972, 1990a). Andrewsianthus bilobus (Mitt.) Grolle is widespread in Africa, including South Africa (cf. Grolle, 1963c; Wigginton & Grolle, 1996; Schuster, 2002a). Two species are endemic to Marion Island, A. carinatus Grolle and A. marionensis (S.W.Arnell) Grolle. Andrewsianthus lancistipulus Grolle of Marion Island was placed in Lophozia by Schuster (2002a, p. 259). One species, A. perigonialis (Hook.f. & Taylor) R.M.Schust., occurs in New Zealand.
3) subg. Pseudotritomaria R.M.Schust., Beih. Nova Hedwigia 119: 323. 2002, has only A. ferrugineus Grolle (Grolle, 1966f), known only from high elevations (4000 m) in Nepal and Bhutan.
Species of Andrewsianthus at times may be confused with Anastrophyllum novazelandiae and A. papillosum as well as small plants of Lophozia autoica or L. multicuspidata (all subfam. Lophozioideae) or even species belonging to other families, such as Acrolophozia, Marsupella and others. These taxa are all of a similar, rather small size with bifid, transversely oriented leaves, have underleaves that are reduced or lacking and have reddish and/or golden brown secondary pigments; a number of these “look-alikes” also have coarse trigones and a strongly papillose surface. The following key to Andrewsianthus and similar genera emphasizes characters found in sterile plants.
Andrewsianthus and Anastrophyllum are very similar in appearance and further studies of this complex should center around the delimitation of these genera. For example, species of Andrewsianthus subg. Cephalolobus have transversely oriented leaves with the dorsal sector of the insertion transverse, just as in Anastrophyllum. Moreover, the taxa of subg. Cephalolobus also tend to form lateral-intercalary branches from the median sector of the leaf axil, i.e., dorsal-intercalary, Andrewsianthus -type branches are not developed. The branch position is very similar to the position that is so very often found in Anastrophyllum. Schuster (2002a, p. 321) remarked that taxa in subg. Cephalolobus “suggest that Andrewsianthus evolved from Anastrophyllum -like ancestral types…and that ultimately it is the universal proclivity for shoot apices to become, usually rather abruptly microphyllous, rhizoid-bearing, and—mostly—geotropic, which is most crucial in delimiting the genus...” One of the difficulties inherent in work with this complex is that some populations of Andrewsianthus only sporadically produce microphyllous flagelliform shoot tips, and these may easily be overlooked. Therefore, a careful search is required to assess the degree of expression of this character.
Species descriptions were adapted, but freely modified, from Schuster (1966c); the generic description and key is adapted but considerably modified from Schuster (2002a).
References: Engel (1972); Grolle (1962b, 1971a); Schuster (1966c, 1968b, 2002a); Váňa (1985).
