Adequacy of Morphological Traits in Discrimination Among Sphaeralcea (Globemallow) in Utah

Water conservation in urban areas can be enhanced by encouraging installation of lowwater landscapes in ornamental settings. Appropriate plant selection for low-water landscapes is complicated by concern about water-use efficiency of plants and as well as their aesthetic value. Sphaeralcea common to Utah are drought-tolerant and have ornamental value. However their widespread use in the industry is hindered by their complex genetics. They are difficult to differentiate morphologically due to presumed natural hybridization among populations. This leads to species misidentification and erodes consumer confidence in the native plant industry. Environmental factors also might account for variation in leaf morphological characters and decrease accuracy in species identification. The objectives of our study were to evaluate the influence of environment on leaf character trait stability, and to use molecular marker technology to investigate taxonomic relationships between species. Live plant materials were collected from several populations each of Sphaeralcea coccinea, S. grossulariifolia, S. munroana, S. parvifolia, and S. leptophylla (control). Voucher specimens were used to confirm species identification using traditional morphological characters. Live plant materials were transplanted from their native habitats into a common garden. Leaf measurements were recorded on established plants. Plants were then pruned back to basal leaves, and measurements recorded again after 6 weeks of shoot regrowth. Principal Component Analysis of leaf morphological data suggested environmentally related plasticity of leaf morphological characters in these species. DNA sequence analysis of nuclear ITS and chloroplast intergenic spacer regions, using universal primer pairs, was not adequate to resolve differences at the species level. Phylogenetic trees constructed from these data indicate relatively recent divergence of the species. The Amplified fragment length polymorphism (AFLP) technique will be used to further characterize the genetic variation among and within these species