Morphological variation among Sticherus flabellatus (Gleicheniaceae) populations of the Sydney region

Abstract

The morphological variation among 14 natural populations of the horticulturally important species, Sticherus flabellatus was assessed by using a set of quantitative whole-plant (sporophyte) and frond characters, and photosynthetic pigments. Of the 14 populations, 11 were located within or on the periphery of the Sydney region, and three populations were outside this region (two north, one south) to represent most of the species’ New South Wales range. Univariate and multivariate statistical analyses revealed significant differentiation of all 14 populations. Discrimination of the populations was based on a subset of whole-plant and frond characters, with photosynthetic pigment ratios exhibiting the greatest variation between populations. These traits exhibited sufficient variation to be useful as markers for population identification and discrimination. The distribution of morphological variation revealed two broad ecotypes; closed forest and open forest. These local adaptations could not be partitioned into geographic regions. The distribution of variation in this species has implications for the horticultural industry and the conservation of natural populations.