Rediscovery of Timmiella acaulon (Timmiellaceae) in the Chaco province, northeastern Argentina

Abstract

Background and aims: Herbarium specimens were reviewed as part of broader project that deals with the diversity of bryophytes from the Chaco province (Argentina). One of the samples matched the description of Timmiella acaulon, a species poorly known. The aim of this work is to record T. acaulon as new to Chaco Province and to describe morphologically and illustrate in detail this remarkable species. M&M: Herbarium samples were analyzed with standard techniques for bryophytes. Examination with scanning electron microscope was made using samples mounted directly on double-sided tape and coated in gold-palladium. Results: Timmiella acaulon is newly registered for Chaco province. A complete and detailed morphological description, and illustrations are here presented. Conclusions: Due to the rediscovery of the species more than 100 years after its original description, the distribution range of T. acaulon is extended to northeastern Argentina, and details of morphological characters of systematic value are provided.