On the Kalahari sand savannas of central Angola, botanists recently described Baphia arenicola, a remarkable “underground tree” in the Legume family.
Its name literally means “growing on sand,” and like other geoxylic plants in the region, most of its woody mass is buried beneath the surface, with only low shoots and small white flowers briefly visible above ground.
➡️ Imagine…Underground forests!! Baphia arenicola is part of a broader growth form known as geoxylic suffrutex (often called “underground trees” or “geoxyles”), in which plants develop massive woody structures below ground and only short-lived, low stems above it.
This strategy has evolved repeatedly in Afrotropical savannas and grasslands, where frequent fire, grazing, and seasonal drought make tall, fully exposed trees vulnerable.
By keeping most of their biomass safely underground, geoxyles can resprout after fire, withstand intense herbivory, and persist for extremely long periods—acting as living archives of old-growth savannas and indicators of intact grassy ecosystems.
Field surveys show B. arenicola is known from just a few localities, yet it can be locally abundant in nutrient-poor grasslands that are unsuitable for agriculture, giving it a current conservation status of Least Concern.
Reference: Goyder, D.J., Gonçalves, F.M.P., & Meller, P. (2023). New species of Asclepias (Apocynaceae), Baphia (Leguminosae) and Thunbergia (Acanthaceae) from Angola’s Kalahari sand woodlands and savannas. PhytoKeys 237: 1–35.