Abstract Detail

Systematics

Li, Gary [1], Fritsch, Peter W. [2].

A revision of the valvate group of Styrax series Cyrta (Styracaceae).

Styrax (Styracaceae) comprises about 130 species of trees and shrubs found in the Mediterranean region, eastern and southeastern Asia, Malesia, and the New World. Although multiple regional floras have covered parts of Styrax taxonomy, a comprehensive taxonomic assessment of the genus has not been conducted since Perkins’ 1907 worldwide treatment in Das Pflanzenreich. To begin to address this, regional taxonomic revisions have been conducted for much of the New World, and for Asia, a treatment of the members of S. series Cyrta with imbricate floral aestivation was accomplished in 2003. Our current research aims to complete the treatment of this series by revising the members of the series with valvate floral aestivation. The valvate group is endemic to East and Southeast Asia, ranging from eastern India through southern China to Micronesia, and south to Borneo, New Guinea, and the Solomon Islands, although it is absent from the Philippines. We examined over 1300 specimens from 26 herbaria with significant holdings of Asian Styrax. Our revision includes a key to species, descriptions, distribution maps, illustrations, lectotypifications, synonymy, and a list of all exsiccatae examined and identified to species. Results warrant the recognition of eleven species. We resurrected S. bracteolatus, S. rubifolius, S. subcrenatus, and S. warburgii as species to be recognized and clarified circumscriptions and nomenclature for the other seven species. Styrax agrestis, here recircumscribed much more narrowly than in prior floras, along with S. bracteolatus and S. rubifolius, are rare endemics of conservation concern. Patterns of morphological variation suggest introgression among species in southeastern China. We observed some problematic specimens with unique combinations of characters whose taxonomic status remains unresolved because only single specimens with either flowers or fruits were available; at least some of these may represent undescribed species. Our work highlights the importance of basic taxonomic work for the protection and management of species and their habitats, and sets the stage for a deeper understanding for Styrax evolution.

1 - California Academy of Sciences, Botany, 55 Music Concourse Drive, San Francisco, CA, 94118, USA
2 - Botanical Research Institute of Texas, 1700 University Drive, Fort Worth, TX, 76107-3400, USA

Keywords:
Styracaceae
Styrax
Asia
Taxonomic revision.

Presentation Type: Oral Paper
Session: 37, Systematics II: Caryophyllids & Basal Asterids
Location: Sundance 4/Omni Hotel
Date: Wednesday, June 28th, 2017
Time: 12:00 PM
Number: 37008
Abstract ID:200
Candidate for Awards:None