A taxonomic revision of the Hebe parviflora complex (Scrophulariaceae), based on morphology and flavonoid chemistry

Two entities have long been recognised at the rank of either species or var iety in the New Zealand endemic Hebe parviflora complex but, because one of the critical type specimens had not previously been examined by New Zealan d botanists, there has been uncertainty regarding the correct application o f names. The two entities can be distinguished on characters of habit, leav es, flowers, leaf flavonoids, and chromosome number, and are accepted here at species rank. H. parviflora is the correct name for the tetraploid entit y previously known as H. parviflora var. arborea, and H. stenophylla is the diploid entity previously known as H. parviflora var. angustifolia (the au tonym var. parviflora has not been used in any recent treatments). H. steno phylla has several distinct geographic races and new names are provided at varietal rank for two of these: var. hesperia occurs in limestone areas nea r the north-west coast of the South Island, between Cape Farewell and the H eaphy River; var, oliveri occurs on exposed bluffs on Stephens Island in Co ok Strait. Circumscription of these varieties leaves var. stenophylla compr ising a range of morphological forms whose relationships require further el ucidation. A comparative study of leaf flavonoids identifies flavonoid char acters that clearly distinguish H. parviflora and H. stenophylla, and the p rofiles of these species are compared with those of the related species H. strictissima and H. traversii. Historical factors affecting the distributio n of H. parviflora and H. stenophylla are discussed, and descriptions, dist ribution maps, and illustrations of diagnostic morphological characters are provided for all taxa.