Observations on <i>Distichophyllum procumbens</i> Mitt. A pleurocarpous and secondarily-aquatic moss new to Nigeria

Abstract

A pleurocarpous moss found to be anchored and thriving on rock in an aquatic habitat at Ago-Iwoye in Ogun State, Nigeria, was identified as Distichophyllum procumbens Mitt. and described. As the moss had been reported to be corticolous and terricolous in Ghana and Cameroon, this is the first report of its occurrence in Nigeria and of its aquatic nature in Africa. Based on field study and microscopic examination of the morphological features of the moss, observations were made on its structural adaptations to an aquatic habitat. The rheophilous adaptations include, shoots turning reddish brown when exposed in the dry season, "stem leaf " having border and strong costa, aperistomate capsule splitting into valves for spore discharge, and the presence of rhizoids only at the base of the stem without any tomentum.