Entosthodon Schwägr.

Plants medium-sized to robust, gregarious, yellow-, brown- or bright green. Stems red-brown, rarely pale, usually branched once by a subperigonial innovation, rarely branched by forking or repeated innovation, in cross-section with a central strand, a parenchymatous medulla, a cortex of 1–3 layers of thick-walled cells, and a ± developed hyalodermis, beset with smooth rhizoids. Leaves larger and more crowded near stem apices, erect-spreading or rarely erect and imbricate, oblong-obovate, spathulate, or rarely ovate-lanceolate, acute, obtuse, or acuminate at apex, rarely cuspidate, concave or plane, serrate at margins by projecting cells or entire; upper laminal cells thin-walled and lax, oblong-hexagonal or oblong, becoming longer and laxer below, a few cells often somewhat inflated at alar angles; marginal cells mostly not differentiated, rarely elongate to form a weak border. Costa single, mostly ending below the leaf apex, rarely excurrent to form a cusp, in cross-section as per family. Axillary hairs present, as per family.

Autoicous, rarely paroicous or polygamous. Perigonia usually single, terminating a shoot from which the perichaetial shoot arises by innovation, with funariaceous paraphyses among the antheridia. Setae straight, weakly or rarely strongly hygroscopic, smooth in N.Z. species, very rarely verrucose; capsules erect or inclined, strongly exserted, symmetric or asymmetric, obovoid, pyriform to narrowly cylindric-pyriform, or rarely ovoid, red-brown at maturity, usually wrinkled at neck and constricted below the mouth when dry, with a neck c. ¼ to ½ the capsule length; mouth equal the capsule diameter, rarely smaller, transverse or oblique; exothecial cells oblong to elongate, 2–8:1 in N.Z. species, not forming vertical bands, in cross-section with thick, cuneate or rarely non-cuneate walls, several rows oblate at mouth; stomata immersed or rarely superficial; annulus absent or rudimentary; operculum plano-convex, rarely mammillate or conic. Peristome double, single, or absent, persistent or fugacious; exostome teeth variably developed, straight or sigmoid, free at apices, not or weakly appendiculate, papillose-striolate to strongly striate; endostome segments variably developed, papillose, coherent at base. Calyptra cucullate-rostrate. Spores subreniform, variously ornamented.

A genus of c. 60–70 species with a nearly cosmopolitan distribution. Six species of Entosthodon occur in N.Z.

The influential treatment of Brotherus (1924) included Entosthodon within a broadly circumscribed Funaria. This broad definition of Funaria was accepted by Dixon (1926), by Sainsbury (1955), and by other workers on the Australasian Funariaceae.

The generic concepts for both Entosthodon and Funaria utilised here are the same as presented for Andean species by Fife (1987). According to these sporophytically defined concepts, the capsules in Entosthodon can be either erect and symmetric with transverse mouths, or inclined and asymmetric with oblique mouths. The peristomes can be variably developed (double, single, rudimentary, or absent) with the exostome teeth (if present) either straight or sigmoid. In all cases, however, the exostome teeth are free at their apices and lack a fused apical lattice, such as found in Funaria. The exothecial cells in Entosthodon usually have, in cross-section, cuneate and thick walls (only rarely non-cuneate) and lack alternating longitudinal bands of thick- and thinner-cell walls. Entosthodon spp. also lack a revoluble annulus. An apical lattice, alternating longitudinal bands of exothecial cells, and a revoluble annulus all characterise Funaria s.s.

No attempt is made here to distinguish at the subgeneric level those Entosthodon species with markedly asymmetric capsules and sigmoid exostome teeth. Such species were placed by Fife (1985, 1987) in a sporophyte-defined Entosthodon subgenus Plagiodus.

Liu et al. (2012) have presented convincing evidence, using 10 molecular markers, that Entosthodon is polyphyletic. Their conclusions are accepted here, and substantial taxonomic and nomenclatural change to Entosthodon, following from their conclusions, seem inevitable. Liu et al. hypothesised that homoplasy is a pervasive feature of sporophyte evolution of Entosthodon and its allies. Consensus concerning the relationships within Entosthodon sensu Fife is unlikely to be reached easily or quickly, even by the use of molecular methods.

As in other genera of Funariaceae, material of Entosthodon with fragmentary sporophytes and/or tattered gametophytes can be difficult or impossible to determine with confidence. A small number of collections, putatively allied to E. apophysatus, exhibit strongly aberrant sporophytes. These collections are discussed under E. apophysatus and their taxonomic status cannot be fully resolved.

E. subnudus var. subcuspidatus (Broth.) Fife [Bryologist 98: 315, 1995] [Basionym: Funaria subcuspidata Broth., Öfvers. Finska Vetensk.-Soc. Förh. 40: 171, 1898]. The type of this taxon (T.W.N. Beckett NZ64, Holotype: H-Brotherus! Isotype: CHR 500758!) was collected in 1887 from the Bridle Path in the Lyttelton Hills (Canterbury L.D.). The type collection has both tattered gametophytes and immature capsules. The former have elongate apical cells and are suggestive of both E. apophysatus and E. subnudus s.l. However, a few of the more intact leaves have differentiated and projecting marginal cells suggestive of E. muhlenbergii. The sporophytes are immature, but in form and dimension (setae 5–7 mm, weakly dextrorse; capsules oblong-cylindric, 2.5–3.2 mm, with a neck c. ½ the total capsule length) are most suggestive of E. apophysatus. The few opercula seen are conic, but this may be a function of immaturity or desiccation. The spores, mostly 33–36 µm, are immature but appear to lack a trilete scar. Confusingly, however, one dissected capsule showed a double peristome with well-developed, weakly sigmoid, striate, and trabeculate teeth c. 385 µm long, and well developed endostome segments c. ⅔ the height of the teeth. The peristome characters are suggestive of E. muhlenbergii. Both E. apophysatus and the rarer E. muhlenbergii occur on the South I. It is best to consider Entosthodon subnudus var. subcuspidatus and its basionym as nomina confusa and to exclude them from further consideration.