"Once part of the supercontinent Gondwana, New Zealand has been isolated by oceanic barriers for at least the last 80 million years. Because of its isolation, heterogeneous landscape, and latitudinal range from the subtropics to the subantarctic, New Zealand hosts a diverse and largely endemic flora. Although the fossil record, morphological diversity, and present distribution patterns may imply an ancient evolutionary history, the mountains of New Zealand were only recently uplifted, and achieved their full elevation only by the late Pliocene... he evolution of the subalpine and alpine flora of New Zealand has largely occurred within the past few million years.
One of the most spectacular adaptive radiations in the mountains of New Zealand is the Hebe complex. According to Garnock-Jones, it forms a putatively monophyletic assemblage of approximately 150 species that range from eastern Australia and New Guinea to South America and the Falkland Islands. The greatest diversity is centred in New Zealand where the Hebe complex consists of several clearly defined lineages that were probably derived from an Australian progenitor." 
"The Hebe Society promotes the cultivation of hebes and other New Zealand native plants." 
Efforts have been underway to expand the number of cultivars available as pot plants since the 1980s. 
 Wagstaff, S. J., & Garnock‐Jones, P. J. (1998). Evolution and biogeography of the Hebe complex (Scrophulariaceae) inferred from ITS sequences. New Zealand Journal of Botany, 36(3), 425-437.
 Hebe Society. (2020). http://www.hebesoc.org/
 Noack Kristensen, L. (1988, August). Hebe cultivars as potential new pot plants. In I International Symposium on the Development of New Floricultural Crops 252 (pp. 235-238).