Conservatoire et Jardin botaniques de la Ville de Genève
Systematics of Dicranaceae
Recent molecular phylogenies of mosses have investigated relationships between the major genera in the Dicranales and the Dicranidae (a monophyletic lineage of mosses consisting of 6 orders, including the Dicranales, with a haploidous peristome) but these studies have also served to highlight the need for a better understanding of the fundamental taxonomy of these groups. With over 1000 species the Dicranaceae s.l. is one of the largest families in the Dicranales. It is a morphologically diverse family which contains both temperate and tropical genera, although the geographic origins of the family itself are not yet fully known. There are many questions that arise in this group relating to their systematic relationships and phylogeographic patterns as well as to patterns of character evolution, especially that of the perisotome. Aims of the programme: To understand the evolution, phylogeny and phylogeography of the Dicranaceae (Dicranales) incorporating studies of taxonomy, morphology-anatomy, phylogeography, population genetics and phylogenetics.
Holomitrium Brid. is one of the largest and most morphologically diverse genera in the Dicranoideae (Dicranaceae, Dicranales). It is a predominately epiphytic genus with around 50 sp. that are found in montane regions across the Neotropics and Paleotropics, as well as in some subtropical areas. The genus Holomitrium will be revised from across its range, completing work already done on the 15 Holomitrium taxa and their putative allies in the Neotropics.
Peristomes have long been used in the classification of mosses at the higher taxonomic levels of families, orders and beyond. Moss peristomes are developmentally conservative structures with established patterns of development. Taxon specific differences at lower taxonomic levels have been found in a number of moss groups. Of particular interest here is whether taxon specific differences can be found between peristome structures at the levels of genera and/or species within the Dicranales, and subsequently whether observed differences contain any phylogenetic signal. Recently published molecular phylogenies of the Dicraniidae will facilitate our investigation of the evolution of the peristome in the Dicranales as well as providing a basis from which assess the value of peristome morphology-anatomy and developmental patterns in the taxomomy of this group of mosses more generally.
The understanding of bryophytes of the montane habitats in the Andes of South America is fragmented and it is these high altitude zones, and especially the paramos, that contains the highest diversity of bryophytes in the tropics. The first phase of this project will focus on collating literature on bryophytes of high altitudes with the aim of preparing a checklist of Paramo Bryophytes. Work will also focus of the databasing and study of herbarium specimens from Paramos. The second phase of the project will focus on the collection of bryophytes from paramos with a specific focus on the study of the Dicranaceae.
Symblepharis Mont. is a predominantly tropical, high-elevation, epiphytic acrocarpous moss genus of around ten species from 35 vaildly published specific names. Of the ten species currently recognised in the genus four are known from the Neotropics (S. fragilis Mitt., S. fuegiana (Cardot) Ochyra, S. krausei (Lorentz) Ochyra & Matteri, S. lindigii Hampe), five from the Paleotropics (S. gracillima Müll. Hal., S. guizhouensis B.C. Tan et al., S. oncophoroides Broth., S. reinwardtii (Dozy & Molk.) Mitt., S. sinensis Müll. Hal.) and one, S. vaginata (Hook. ex Harv.) Wijk & Margad., has been recorded from Asia, North America and South America. Symblepharis was first described by Montagne in 1837 based on S. helicophylla Mont. from South America. It was partially revised in 1898, with a focus on South America, and three new varieties were described from this region (Salmon, 1898). Although Symblepharis has since been treated in regional floras (China - Chien & Crosby 1999; Central America - Allen 1994; East India - Gangulee, 1971; Mexico - Ireland 1994; North America - Ireland 2007) it has not been revised from across its range and both its taxonomy, and its systematic positioning within the Dicranales, are in need of a modern reevaluation.