Dicranellaceae
Autoicous or dioicous. Asexual propagules absent. Turves, tufts or loose mats on soil or rocks. Stems simple, forked or branched by innovation, with rhizoids restricted to base of branches or stems; central strand present. Leaves monomorphic or becoming larger toward apex, ovate to lanceolate, falcate-secund or straight and erect or erect-spreading when moist, scarcely altered to becoming erect or appressed when dry, often with a sheathing base; apex acute or subulate; costa single, subpercurrent, percurrent or excurrent, sometimes broad and more than 1/3 of leaf width at base or weak to absent at base; margin entire, serrulate or serrate, plane or recurved, without a border; laminal cells rhomboid, elliptic or short-rectangular, becoming longer toward base, smooth; alar cells not differentiated. Acrocarpous. Perichaetial leaves often differentiated from lower vegetative leaves by size and shape. Capsule erect to pendulous, curved or straight, immersed or exserted, operculate, sometimes furrowed when dry, with a well-developed annulus or annulus poorly differentiated. Calyptra cucullate or mitrate, smooth or rough, glabrous. Operculum conic, conic-apiculate or obliquely rostrate. Peristome absent or a single series of 16 teeth divided into two or three (not in Victoria) segments.
The circumscription of this family is still not clear, which is mostly due to uncertainty regarding the circumscription of Dicranella (see below), but is likely to comprise around nine genera; potentially two genera and six species in Victoria.
The placement of Victorian Dicranella species within this family is uncertain. Based on a limited sampling of species that did not include any Victorian species, Dicranella has been shown in its current circumscription to be composed of multiple lineages scattered throughout combined chloroplast and mitochondrial sequence phylogenies of mosses with a single (haplolepideous) peristome series (Santos et al. 2021). In the suggested circumscription of Dicranellaceae of Santos et al. (2021), only one of these Dicranella lineages belongs to Dicranellaceae and based on the morphological features that seem to characterise this lineage of Dicranella, at least one of the Victorian species, D. dietrichae (Müll.Hal.) A.Jaeger, is almost certainly misplaced in Dicranella and this family. Phylogenetic analysis of DNA sequences from a more comprehensive sample of species is required to better establish the lineages harbored within Dicranella and to confirm which lineages the Victorian species belong to. Until this can be accomplished and alternative classifications for misplaced Dicranella are proposed, all Dicranella species are tentatively recognised here in the Dicranellaceae. The alternative and more traditional placement of Dicranella in Dicranaceae is also unsatisfactory as none of the Dicranella lineages are placed within the Dicranaceae lineage in chloroplast phylogenies (La Farge et al. 2002; Santos et al. 2021).
Eccremidium is also tentatively recognised here in the Dicranellaceae based on the placement of E. floridanum in the lineage that Santos et al. (2021) propose as delimiting the Dicranellaceae. However, given the misplacement of species seen in Dicranella, it seems preferable that the placement of Victorian Eccremidium species in this family be also confirmed through phylogenetic analyses of chloroplast DNA sequences.
La Farge, C.; Shaw, A.J.; Vitt, D.H. (2002). The circumscription of the Dicranaceae (Bryopsida) based on the chloroplast regions trnL-trnF and rps4. Systematic Botany 27: 435–452.
Santos, M.B.; Fedosov, V.; Hartman, T.; Fedorova, A.; Siebel, H.; Stech, M. (2021). Phylogenetic inferences reveal deep polyphyly of Aongstroemiaceae and Dicranellaceae within the haplolepideous mosses (Dicranidae, Bryophyta). Taxon 70: 246–262.