Ptychostomum

Ptychostomum is a genus of mosses belonging to the family Bryaceae. It has an almost cosmopolitan distribution. It has two subgenera, Psychostomum (Ptychostomum) and Psychostomum (Cladodium).

Species
The following species are recognised in the genus Ptychostomum:
 * Ptychostomum acutiforme (Limpr.) J.R. Spence
 * Ptychostomum altisetum (Müll.Hal.) J.R.Spence & H.P.Ramsay
 * Ptychostomum amblyodon (Müll. Hal.) Chen Y. Wang & J.C. Zhao
 * Ptychostomum angustifolium (Brid.) J.R.Spence & H.P.Ramsay
 * Ptychostomum archangelicum (Bruch & Schimp.) J.R. Spence
 * Ptychostomum arcticum (R. Br.) J.R. Spence
 * Ptychostomum austriacum (Köckinger, Holyoak & Suanjak) D. Bell & Holyoak
 * Ptychostomum badium (Bruch ex Brid.) J.R.Spence
 * Ptychostomum bimum (Schreb.) J.R. Spence
 * Ptychostomum bornholmense (Wink. & R. Ruthe) Holyoak & N. Pedersen
 * Ptychostomum bryoides (R.Br.) J.R.Spence
 * Ptychostomum calophyllum (R. Br.) J.R. Spence
 * Ptychostomum capillare (Hedw.) Holyoak & N. Pedersen
 * Ptychostomum cellulare (Hook.) D. Bell & Holyoak
 * Ptychostomum cernuum (Hedw.) Hornsch.
 * Ptychostomum chorizodontum (Cardot & Broth.) J.R. Spence
 * Ptychostomum compactum Hornsch.
 * Ptychostomum creberrimum (Taylor) J.R. Spence & H.P. Ramsay
 * Ptychostomum cryophilum (Mårtensson) J.R. Spence
 * Ptychostomum cyclophyllum (Schwägr.) J.R. Spence
 * Ptychostomum cylindrothecium (R. Br. bis) J.R. Spence & H.P. Ramsay
 * Ptychostomum dicarpum (E.B. Bartram) J.R. Spence
 * Ptychostomum donianum (Grev.) Holyoak & N. Pedersen
 * Ptychostomum elegans (Nees ex Brid.) D. Bell & Holyoak
 * Ptychostomum funkii (Schwägr.) J.R. Spence
 * Ptychostomum hawaiicum (Hoe) J.R. Spence
 * Ptychostomum imbricatulum (Müll. Hal.) Holyoak & N. Pedersen
 * Ptychostomum inclinatum (Sw. ex Brid.) J.R.Spence
 * Ptychostomum intermedium (Brid.) J.R. Spence
 * Ptychostomum knowltonii (Barnes) J.R. Spence
 * Ptychostomum lamprochaete (Dusén) J.R. Spence
 * Ptychostomum lonchocaulon (Müll. Hal.) J.R. Spence
 * Ptychostomum longisetum (Blandow ex Schwägr.) J.R. Spence
 * Ptychostomum marratii (Hook. & Wilson) J. R. Spence
 * Ptychostomum meesioides (Kindb.) J.R. Spence
 * Ptychostomum minii (Podp. ex Guim.) D.Bell & Holyoak
 * Ptychostomum moravicum (Podp.) Ros & Mazimpaka
 * Ptychostomum neodamense (Itzigs.) J.R. Spence
 * Ptychostomum nitidulum (Lindb.) J.R. Spence
 * Ptychostomum ovatum (Hedw.) J.R.Spence
 * Ptychostomum pacificum J.R. Spence & Shevock
 * Ptychostomum pallens (Sw.) J.R. Spence
 * Ptychostomum pallescens (Schleich. ex Schwägr.) J.R. Spence
 * Ptychostomum pauperculum (E.B. Bartram) J.R. Spence
 * Ptychostomum pendulum Hornsch.
 * Ptychostomum pseudotriquetrum (Hedw.) J.R. Spence & H.P. Ramsay ex Holyoak & N. Pedersen
 * Ptychostomum reedii (H. Rob.) J.R. Spence
 * Ptychostomum rubens (Mitt.) Holyoak & N. Pedersen
 * Ptychostomum rutilans (Brid.) J.R. Spence
 * Ptychostomum salinum (I. Hagen ex Limpr.) J.R. Spence
 * Ptychostomum schleicheri (DC.) J.R. Spence
 * Ptychostomum sibiricum (Lindb. & Arnell) J.R. Spence
 * Ptychostomum subneodamense (Kindb.) J.R. Spence
 * Ptychostomum torquescens (Bruch & Schimp.) Ros & Mazimpaka
 * Ptychostomum touwii Bijlsma, Kruijer & M. Stech
 * Ptychostomum turbinatum (Hedw.) J.R. Spence
 * Ptychostomum vermigerum (Arnell & C.E.O. Jensen) J.R. Spence
 * Ptychostomum vernicosum (Dusén) J.R. Spence
 * Ptychostomum warneum (Schwägr. ex Steud.) J.R. Spence
 * Ptychostomum weigelii (Biehler) J.R.Spence
 * Ptychostomum wrightii (Sull. & Lesq.) J.R. Spence