Afonina, O.M., E.A. Ignatova, V.E. Fedosov & O.I. Kuznetsova. Toward a new understanding of Syntrichia submontana (Pottiaceae, Bryophyta)
Arctoa (2014) 23: 11-24. doi: 10.15298/arctoa.23.03
Syntrichia submontana (Broth.) Ochyra has been previously reported from Tajikistan, Kyrgyzstan and Mongolia. It was considered to be dioicous, with sporophytes unknown. Our study of extensive herbarium collections from Mongolia, southern Siberia and the Caucasus, as well as some collections from China revealed that this species has a much wider distribution in Asia. Its sexual condition is polyoicous: autoicous plants are most frequent, with antheridia and paraphyses lacking perigonial leaves, forming a group just below the perichaetium, but occasionally also male, female and, more rarely, synoicous plants are found in the same tuft. Mature sporophytes are rare in Mongolian collections, but they are frequent in China, southern Siberia and the Caucasus. Peristomial basal membrane is very low, consisting of 1-2(-3) cell rows. S. submontana is similar in gametophytic characters to S. sinensis (Müll. Hal.) Ochyra, and their close relationship was confirmed by molecular study (nrITS2). A description of S. submontana is amended and supplemented by sporophyte characteristics. Syntrichia longimucronata (X.J. Li) R.H. Zander is synonymized with S. submontana. Descriptions, illustrations, distribution and ecological data are provided for S. submontana and S. sinensis. Our molecular data also found two distinct entities within the morphologically variable S. laevipila Brid., which tentatively confirms recognizing of S. pagorum Milde as a separate species. Specimens of S. caninervis var. astrakhanica Ignatov, Ignatova & Suragina from distant localities are also resolved in a clade separated from S. caninervis var. caninervis; thus the variety likely deserves being raised to the species level.