Anomodontopsis Ignatov & Fedosov, 2019

Anomodontopsis Ignatov & Fedosov View in CoL , gen. nov.

Type species: Anomodontopsis rugelii (Müll. Hal.) Ignatov & Fedosov. – Basionym : Hypnum rugelii Müll. Hal., Syn. Musc. Frond. 2: 473. 1851.

Etymology: alluding similarity to the genus Anomodon .

Diagnosis. Similar to Anomodon in the broadly rounded leaf apex and leaf shape, but differs in the compound proximal branch leaves, and the auriculate leaf base, as well as in molecular data ( Figs. 1–6 View Fig View Fig View Fig View Fig View Fig View Fig ).

Additional characters: North American, European and West Asian plants are dark green to rusty brown, which alone allows the species to be recognized in the field. In East Asia there are probably two infraspecific taxa, one of which was recognized by Iwatsuki as A. rugelii var. ferrugineus (Besch.) Z. Iwats. However , this form is the same as plants from America, from where A. rugelii was described. Also in the Russian Far East there is another form of A. rugelii , which is slightly different molecularly and has more or less glaucous shoots, less different from species such as A. viticulosus and A. thraustus ; in such plants the leaves are contorted, but not so conspicuously incurved as in North American and European plants. Granzow-de la Cerda (1997) found transitions and did not recognize these forms at all. Further molecular studies with expanded sampling may reveal that in East Asia there are two taxa of Anomodontopsis .

Description: Plants medium-sized, in rather dense mats, dark green, brownish or, in some populations, somewhat glaucous-green. Stems erect-ascending, weakly irregularly branched, central strand differentiated; proximal branch leaves compound; rhizoids often abundant. Branch leaves in dry state contorted and often incurved, when wet erect-spreading to subcomplanate, broadly oblong-ligulate, conspicuously auriculate, with auricles papillose on the side facing the stem; margins plane, almost entire; apex broadly rounded or occasionally apiculate; costa strong, pellucid, white or with golden to rusty pigmentation, ending shortly below apex, often flexuose, sometimes with lateral offshoots and forked at apex, epidermal cells smooth; laminal cells isodiametric, small, thick-walled, with high, usually pedicellate papillae on both surfaces, basal juxtacostal cells elongate, pellucid, smooth, occupying half of leaf width. Dioicous. Perichaetia at ends of terminal secondary branches; perichaetial leaves from broad base abruptly constricted to narrowly lanceolate apex, laminal cells papillose. Capsule exserted on a long seta, symmetric, cylindrical. Annulus persistent; operculum obliquely short-rostrate, exostome teeth papillose or indistinctly striolate proximally, endostome with short basal membrane, segments short, irregular or absent. Spores small, 9–14 ìm. Calyptra smooth. Capsules mature in mid-autumn.

The other species of the genus currently accepted in the Tropicos database all belong to the genus Anomodon s. str.: A. dentatus C. Gao is accepted by Granzow-de la Cerda (1997) and Wu et al. (2002), Anomodon perlingulatus Broth. ex P.C. Wu & Y. Jia is accepted by Wu et al. (2002), while Anomodon rotundatus Paris & Broth. was tentatively synonymized with A. thraustus ( Wu et al., 2002) and A. grandiretis Broth. was placed into synonymy with Anomodon minor ( Wu et al., 2002) .