Lectotypification on Acroporium hyalinum (Reinw. ex Schwägr.) Mitt. (Hypnales: Sematophyllaceae)

Abstract

Acroporium hyalinum (Reinw. ex Schwägr.) Mitt., an older name than Acroporium stramineum (Reinw. & Hornsch.) M.Fleisch. for this taxon, is applied here in accordance to the principle of nomenclatural priority. The Acroporium hyalinum is broadly circumscribed by its erect-spreading, broadly lanceolate leaves with short acuminate tips. Its infra-specific delimitation, however, has not been clearly defined. Based on careful examination of nearly 200 specimens, including 35 types associated with A. hyalinum, all the three varieties proposed by Tan in 1994 (Acroporium stramineum (Reinw. & Hornsch.) M.Fleisch. var. stramineum, A. stramineum var. hamulatum (M.Fleisch.) B.C.Tan, and A. stramineum var. turgidum (Mitt.) B.C.Tan) are accepted here as Acroporium hyalinum (Reinw. ex Schwägr.) Mitt. var. hyalinum, A. hyalinum var. hamulatum (M.Fleisch.) M.S.Chua & B.C.Ho and A. hyalinum var. turgidum (M.Fleisch.) M.S.Chua & B.C.Ho, respectively, the latter two names being new combinations. Descriptions and an identification key of these three varieties are provided, along with taxonomic notes and illustrations. Lectotypification of Hypnum hyalinum Reinw. & Hornsch. is proposed.