Alexander von Humboldt, Aspects of nature, in different lands and different climates… (1849)
“ In these physiognomic considerations we by no means comprise under the name of Heaths the whole of the natural family of Ericaceæ, which on account of the similarity and analogy of the floral parts includes Rhododendron, Befaria, Gaultheria, Escallonia, &c. We confine ourselves to the highly accordant and characteristic form of the species of Erica, including Calluna (Erica) Vulgaris, L., the common heather. ”
