Morphological variation within the genus Blandfordia (Liliaceae) in relation to Its environment

Abstract

The taxa in Blandfordia are often difficult to separate morphologically. A multivariate morphometric analysis of data from both herbarium and field samples suggests that the genus consists of at least four polythetically distinct taxa, corresponding to the traditional concepts of B. cunninghamii Lindley, B. grandifora R.Br., B. nobilis Smith, and B. punicea (Labill.) Sweet. The morphological boundaries between most of these species are arbitrary but are closely related to a number of environmental variables. Due to large intra-population variability, discrimination between these taxa is possible only on the basis of a combination of attributes, notably leaf width and margin sculpturing, and flower length and diameter. The morphological distinction between B. punicea and the other species is clear and seems to be maintained by its geographical isolation. The distinction between B. grandiflora and B. cunninghamii is based on vegetative rather than floral attributes and is made difficult by phenotypic response of B. cunninghamii plants to light intensity. Gene flow between these two species appears to be restricted by their separate habitats. The distinction between B. grandiflora and B. nobilis is based on floral rather than vegetative attributes and is related to latitude with the species being more distinct in the area of parapatry than in the area of allopatry. In the small area of sympatry there appears to be introgression of B. nobilis attributes into B. grandiflora populations.