Xerophyta is a genus of monocotyledonous flowering plants in the family Velloziaceae, placed in the order Pandanales. The genus was described in 1789 by Antoine Laurent de Jussieu and comprises around 20 accepted species distributed across sub-Saharan Africa, Madagascar, and the Arabian Peninsula.
Plants in the genus are notable for their extraordinary capacity to survive desiccation. Several species are poikilochlorophyllous, meaning they dismantle their photosynthetic apparatus — losing chlorophyll and halting both photosynthesis and transpiration — during prolonged drought. Upon return of moisture, they regenerate chloroplasts and resume full metabolic activity. This strategy is among the most extreme forms of vegetative desiccation tolerance known in flowering plants.
Research on the genome of Xerophyta viscosa has indicated that this desiccation tolerance is underpinned by the same genetic toolkit employed by orthodox seeds in most angiosperms — suggesting an evolutionary co-option of seed-survival mechanisms in vegetative tissue.
The genus name reflects this defining characteristic: it derives from the Ancient Greek ξηρός (xeros, "dry") and φυτά (phutá, "plants"). Xerophyta species are typically found in rocky outcrops, cliff faces, and seasonally arid habitats across Africa and its associated island systems, where extreme moisture fluctuation is the norm.
Etymology
The name Xerophyta was coined by Antoine Laurent de Jussieu in 1789 and derives from the Ancient Greek ξηρός (xeros, "dry") and φυτά (phutá, "plants"), directly referencing the genus's defining tolerance of extreme drought conditions.
Distribution
Xerophyta is native to sub-Saharan Africa, Madagascar, and the Arabian Peninsula. Species are characteristically found on rocky outcrops, cliff ledges, and other exposed habitats subject to seasonal or prolonged drought.
Ecology
Several Xerophyta species are poikilochlorophyllous — they dismantle their chloroplasts and cease photosynthesis entirely during drought, then reconstitute functional photosynthetic machinery once water returns. Genome studies of Xerophyta viscosa suggest this vegetative desiccation tolerance co-opts the genetic programme normally used by desiccation-tolerant seeds in flowering plants.
Taxonomy Notes
Xerophyta belongs to the family Velloziaceae in the order Pandanales (kingdom Plantae, phylum Anthophyta). Several species formerly placed in Xerophyta have been moved to related genera including Barbaceniopsis, Nanuza, and Vellozia. GBIF records approximately 20 accepted descendants.
