Examples of the variation in habitats and growth forms of woody Spermacoceae. (A, B) habitats plus growth form; (C–F) growth form. (A) Overview of Kalahari sand plateau (Mwinilunga, Zambia) where Spermacoce manikensis grows (geoxylic herb; inset, detail of habit). (B) Shore of Lake Bangweulu (Zambia) with S. bangweolensis (inset, detail of habit). (C) Gomphocalyx herniarioides, geoxylic herb (south-west Madagascar). (D) Lathraeocarpa acicularis, shrub (south-west Madagascar). (E) ‘Oldenlandia’ ambovombensis, shrub (south Madagascar). (F) ‘Oldenlandia’ humbertii, shrub (south-west Madagascar).