Madagascar is a world’s biodiversity hotspot, showing exceptionally high levels of species rich- ness and endemism. Despite the island’s pro- longed geographic isolation (150 to 160 Ma from Africa, 84 to 90 Mya from India), most of its extant endemic plant species are the result of recent long-distance dispersals, mainly from continen- tal Africa. The genus Helichrysum is a relevant study-case to explore the evolutionary and bio- geographic history of Malagasy flora because it represents one-fifth of the Compositae species of the island. We generated a time-calibrated phylogeny of 350 Helichrysum species (including 60% of the Malagasy endemics) based on tar- get-enrichment DNA sequence data and con- ducted ancestral range estimation analyses. Our results reveal at least six independent dispersal events to Madagascar from African regions since the Pliocene. Notably, Madagascar was colonized at least twice by lineages originating from the Tropical Afromontane region, leading to signifi- cant subsequent radiations in the island’s high- lands and mountains. The southern African mon- tane grasslands have also played a key role in Madagascar’s colonization, originating at least three clades on the island, one of which notably diversified. Helichrysum mahafaly, endemic to the arid SW region of Madagascar, was inferred to originate from an ancestor coming from the arid region of SW Africa. The similarity of habitats between source and colonized areas suggests the prevalence of niche conservatism, a common phenomenon in allopatric speciation following the colonization of a newly isolated region. Our results underscore the affinities between conti- nental Africa and Madagascar’s montane floras. The main radiations of Helichrysum in Madagas- car’s mountains occurred within the last 2 My, coinciding with a transition towards a cool, arid climate and the expansion of open habitats, and were likely driven by a combination of allopatric and ecological speciation.