New species of Sphagnum from the Philippines with remarkable morphological characters

Abstract

Sphagnum apopenneysii B.C. Tan, Ignatov, Ignatova, & B. Mishler is described as a species new to science. It was found submerged in a high mountain lake, at 2385 m elev. on Mt. Apo on Mindanao island in the Philippines. The new species is peculiar in its poor expression of leaf cell dimorphism. Cells in the upper half of the branch leaves are all identical, linear-vermicular, and all have chloroplasts and nuclei. In the mid-leaf, a moderate differentiation in shape appears with larger cells, approaching in shape to hyalocysts, yet still containing chlorophyll. Only near the base of the branch leaves is a pattern common to most Sphagnum species observed, including inflated hyalocysts with fibrils, albeit without any pores. Collections from deeper water have long lanceolate leaves, while plants from shallower water have stem leaves that are ovate-triangular, similar to those in many species of Sphagnum in section Cuspidata. Both nuclear and plastid DNA sequence data support the placement of this new moss in section Cuspidata.