THE GENUS ORTHOTRICHUM HEDW. (ORTHOTRICHACEAE, MUSCI) IN SOUTHEAST ASIA. A TAXONOMIC REVISION

Abstract

  Thirtyeight taxa of Orthotrichum Hedw. (thirtysix species and two varieties) are reported from Southeast Asia. Seven species (O. pulchrum Lewinsky, O. tortifolium Lewinsky, O. taiwanense Lewinsky, O. erosum Lewinsky, O. schoddei Lewinsky, O. subpumilum Lewinsky, O. sinuosum Lewinsky), one variety (O. hookeri var. granulatum Lewinsky) and one combination (O. laevigatum Zett. var. japonicum (Iwats.) Lewinsky) are new. A section Callistoma Iwats. & Sharp is elevated to the rank of subgenus Callistomum (Iwats. & Sharp) Lewinsky. The remaining taxa reported are: O. firmum Vent., O. hookeri Mitt., O. brassii Bartr., O. dasymitrium Lewinsky, O. leiolecythis C. Muell., O. striatum Hedw., O. speciosum Nees, O. rupestre Schwaegr., O. sordidum Sull. & Lesq., O. affine Brid., O. obtusifolium Brid., O. exiguum Sull., O. anomalum Hedw., O. cupulatum Brid., O. ibukiense Toy., O. urnigerum Myr., O. griffithii Dix., O. crispifolium Broth., O. hooglandii Bartr., O. alpestre B.S.G., O. erubescens C. Muell., O. meyenianum Hamp., O. revolutum C. Muell., O. pallens Brid., O. pumilum Sw., O. rogeri Brid., O. crenulatum Mitt., O. callistomum B.S.G. All species are described and illustrated. A key is provided.

  The species are montane in Kashmir, the Himalayas, southeastern China, Taiwan and New Guinea, found between ca. 2.000 and 4.000 m; in Japan, Korea and eastern China they are also present at sea level. Taxa from the southern region are of Gondwanalandic origin, whereas those of the northern parts are identical with or closely related to those of mainly Northern Hemispheric distribution.

  SEM-studies of peristomes of O. griffithii, O. crispifolium, O. hooglandii, O. callistomum and O. tortifolium support their apomorphic character.