Athyrium haleakalae (Athyriaceae), a new rheophytic fern species from East Maui, Hawaiian Islands: with notes on its distribution, ecology, and conservation status

Kenneth R Wood; Warren L Wagner

doi:10.3897/phytokeys.76.11637

Athyrium haleakalae (Athyriaceae), a new rheophytic fern species from East Maui, Hawaiian Islands: with notes on its distribution, ecology, and conservation status

PhytoKeys. 2017 Jan 19:(76):115-124. doi: 10.3897/phytokeys.76.11637. eCollection 2017.

Authors

Kenneth R Wood¹, Warren L Wagner²

Affiliations

¹ National Tropical Botanical Garden, 3530 Papalina Road, Kalāheo, HI 96741, USA.
² Department of Botany, Smithsonian Institution, PO Box 37012, Washington, DC 20013-7012, USA.

Abstract

Athyrium haleakalae K.R. Wood & W.L. Wagner (Athyriaceae), a small lithophytic fern from East Maui, Hawaiian Islands, is described and illustrated. Notes on its distribution, ecology, and conservation status are also presented. The new species appears to be an obligate rheophyte, preferring sites of fast moving water along concave walls of streams and waterfalls. Athyrium haleakalae differs from the only other known Hawaiian Athyrium, Athyrium microphyllum (Sm.) Alston, in having rhizomes 1-3 cm long and lanceolate blades 1- to 2-pinnate-pinnatifid, 3-8(-11) × 1-3(-4) cm, as compared to Athyrium microphyllum having rhizomes (10-)15-30 cm long and ovate to ovate-triangular blades 3-pinnate-pinnatifid to 4-pinnate, 30-82 × 20-50 cm.

Keywords: Athyriaceae; Athyrium; Critically Endangered; East Maui endemic; Hawaiian Islands; new species; rheophyte.