Ancient Plant Lineages Endemic to Africa and Its Islands: An Analysis on the Distribution and Diversity

Abstract

Although Africa and Madagascar host numerous endemic plant families and genera, there has been no attempt to use recent phylogenies in order to summarise information on their age or map their distribution and diversity. Here, we list 35 plant lineages endemic to Africa and its islands deemed to be older than 100 Mya, map their distribution, richness, and weighted endemism, and discuss intrinsic and extrinsic factors that may have facilitated their survival. High concentrations of ancient endemic lineages are found in the Cape and more broadly across southern Africa, in the Congolian rainforests, but also in East Africa and Madagascar, these last two areas sharing surprisingly many lineages. Africa and its islands host a highly distinctive assemblage of unique plant lineages, adapted to humid, mesic, dry, and in several cases fire-prone, environments. A better understanding of their history and ecology will facilitate their conservation in a changing climate.

The Greater Midlands—A Mid-Elevation Centre of Floristic Endemism in Summer-Rainfall Eastern South Africa

“…6-7%), estimated at around 3000-4000 vascular species. Poor gymnosperm representation is partly due to antiquity and association with palaeo-climates [45]. Dominance of angiosperms, globally the largest and youngest phylum of plants, took place during the Cretaceous period (ca.…”

“…Most of the CE endemics are cycads or asclepiads. Cycads (Cycadales-Zamiaceae) are one of Africa's ancient phylogenetic endemic lineages likely older than 100 Ma [45] and amongst the most threatened plant groups on Earth with 60% at risk of extinction [96]. This is attributed to high levels of illicit harvesting for the horticultural trade (private collections and landscaped gardens) and traditional medicine [97,98].…”

“…This is attributed to high levels of illicit harvesting for the horticultural trade (private collections and landscaped gardens) and traditional medicine [97,98]. Ancient floristic lineages such as cycads are high conservation priorities [45]. Several CE Apocynaceae are highly range-restricted, known only from single localities, rendering them extremely vulnerable to extinction.…”