ANIMADVERSIONS ON THE MOSS GENUS CRATONEURON (SULL.) SPRUCE

Abstract

  A review of taxonomic problems in Cratoneuron (Sull. in Gray) Spruce is provided and all taxa that had previously been included in the genus are discussed at length. Cratoneuron, since its inception, has been an unnatural and polyphyletic taxon and all the species of the genus, except C. filicinum (Hedw.) Spruce, are transferred to other genera, leaving Cratoneuron monotypic. Hypnum fallax Brid., Cratoneuron punae C. Muell., C. formosanum Broth., C. procerum (Dix.) Broth. and C. subcurvicaule P. Varde are reduced to synonymy with C.filicinum. One distinct variety, C. filicinum var. atrovirens (Brid.) Ochyra, is recognized and it includes the plants that have frequently been named C. filicinum var. fallax (Brid.) G. Roth by most workers, and Hypnum vallis-clausae Brid. and Amblystegium formianum Fior.-Mazz. are identical to this variety. The monotypic family Cratoneuraceae Moenk. is restored to accommodate Cratoneuron and it is considered to be related to the Leskeaceae. The taxonomic status of Hypnum curvicaule Jur., a species that for a long time has been treated as C. filicinum var. curvicaule (Jur.) Moenk., is discussed at length. This taxon is retained in the Amblystegiaceae in the new genus Callialaria Ochyra as C. curvicaulis (Jur.) Ochyra. Cratoneuron commutatum (Hedw.) G. Roth and C. decipiens (De Not.) Loeske are transferred to the newly erected genus Palustriella Ochyra that is allied to Helodium (Sull.) Warnst. and its relatives as P. commutata (Hedw.) Ochyra and P. decipiens (De Not.) Ochyra. Several varieties of the former C. commutatum and C. decipiens are given formal names in Palustriella, including P. commutata var. diastrophylla (Brid.) Ochyra, P. c. var. falcata (Brid.) Ochyra, P. c. var. fluctuans (B., S. & G.) Ochyra, P. c. var. irrorata (Mikut.) Ochyra, P. c. var. minor (Lesq.) Ochyra, P. c. var. pseudodecipiens (Amann) Ochyra, P. c. var. ptychodioides (G. Roth) Ochyra, P. c. var. sulcata (Lindb.) Ochyra and P. decipiens var. napaeiformis (Schiffn.) Ochyra, while Cratoneuron commutatovirescens Amann and C. sulcatoirrigatum Meyl. are tentatively reduced to the status of varieties within P. commutata as P. c. var. commutatovirescens (Amann) Ochyra and P. c. var. sulcatoirrigata (Meyl.) Ochyra. A brief assessment of the Thuidiaceae is presented and its subfamily Helodioideae Fleisch. is raised to family rank as Helodiaceae (Fleisch.) Ochyra. Apart from Helodium and Palustriella it includes Bryochenea Gao & Chang and Actinothuidium (Besch.) Broth., while Bryonoguchia Iwats. & Inoue and Hylocomiopsis Card. are excluded from the family. A key for separation of the genera of the Helodiaceae is given. Other heterogeneous elements in Cratoneuron are also discussed. C. perplicatum (Dusén) Broth. and C. submersum Herz. are identical to Drepanocladus longifolius (Mitt.) Broth. ex Par.; C. sordidum (C. Muell.) Broth. and C. drepanocladioides Broth. in Dryg. are inseparable from Drepanocladus sendtneri (Schimp.) Warnst.; C. mendozense Herz. is placed in synonymy with Drepanocladus aduncus (Hedw.) Warnst.; and Hypnum filicinum var. minus Wils. & Hook. f., Cratoneuron kerguelense (Mitt.) Broth. and C. arcticum Steere are considered to be synonymous with Pseudoleskea chilensis (Lor.) Ochyra. The conspecificity of the latter species has considerably extended the range of P. chilensis that is now established as a bipolar disjunct.