A taxonomic revision of Hedwigiaceae Schimp. from the Sino-Himalaya

Abstract

A taxonomic revision of Hedwigiaceae Schimp. from the Sino-Himalaya is provided. This region includes the Himalaya and the Hengduan Mountains of western China (Yunnan, Sichuan, and Xizang Provinces); recent fieldwork in this region has resulted in new collections of Hedwigiaceae which required taxonomic revision. Light microscopy and SEM were used to explore taxonomic characters significant for genus and species delimitation; diversity of leaf papillae was found to be particularly useful at both genus and species level. Five species of Hedwigiaceae are reported from the region: Braunia attenuata (Mitt.) A.Jaeger., B. alopecura (Brid.) Limpr., Hedwigia stellata Hedenäs, H. ciliata (Hedw.) P.Beauv., and H. emodica Hampe ex Müll.Hal. Descriptions and keys are provided to the genera and species; Braunia delavayi Besch. is synonymized under B. attenuata. Observations on the ecology and phytogeography of regional Hedwigiaceae are discussed. Braunia attenuata and B. alopecura are reported as new to Nepal; Hedwigia stellata is reported as new to the Sino-Himalaya (India, Nepal, Bhutan, and China) and H. emodica new to Nepal and China.

Keywords:

• Hedwigiaceae
• Braunia
• Hedwigia
• Himalaya
• China

The Royal Botanic Garden Edinburgh is thanked for providing facilities for the MSc study under which this project was undertaken, and NERC for awarding ND a studentship for this course. The authors wish to thank the curators of the herbaria at Natural History Museum, London, Botanical Museum, Helsinki, and The Linnean Society of London for loan of types and other specimens. Frieda Christie is thanked for assistance with SEM work. Tom Blockeel (Sheffield) and Efrain de Luna (Xalapa) and an anonymous referee are thanked for comments on drafts of this paper and Lars Hedenäs (Stockholm) for advice and unpublished information.

Taxonomic Additions and Changes: Braunia attenuata (Mitt.) A.Jaeger (Braunia delavayi Besch., syn. nov.).