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Tuhinga 15: 27 - 41
ABSTRACT: This paper investigates geographic variation in Hebe macrantha, endemic to mountains of South Island, New Zealand. It assesses the attributes, distribution, and appropriate taxonomic status of its two previously described varieties, the validity and circumscriptions of which have been questioned by some taxonomists. Morphometric analyses support the existence of two distinguishable entities that equate with previous circumscriptions of these varieties, whose continued recognition is recommended. Variety brachyphylla occurs in the north of the species’ geographic range, from the Anatoki Range, northwest Nelson, to the Hanmer Range, north Canterbury. Variety macrantha is geographically more widespread and morphologically more variable. It occurs in the south of the species’ range, south and west from Mt Haast (southwest Nelson) and Lewis Pass (south Nelson/north Canterbury), as well as at Lake Tennyson (southeast Nelson), the only locality at which specimens assigned to both varieties occur. The two varieties are morphologically most similar at localities close to their geographic interface. Patterns of variation in leaf flavonoids neither strongly support nor contradict recognition of the two varieties. Analysed samples share a similar and, within Hebe, distinctive flavonoid profile, and the distribution of two flavonoid glycosides is partly correlated with the morphological circumscription of varieties (the correlation is incomplete in samples taken near the geographic interface of varieties). A distribution map and a table of key morphological differences between varieties are provided.
KEYWORDS: Hebe macrantha, Scrophulariaceae, Plantaginaceae, flavonoids, New Zealand flora.