SIVFLORA 3.0: Southern Islands Vascular Flora database

The Southern Islands Vascular Flora (SIVFLORA) 3.0 dataset is an update of an open-access compilation of vascular plant occurrence records from the islands of the Southern Ocean. It assembles 16,661 records representing 886 taxa (species and infraspecific ranks) in 320 genera, 91 families, 41 orders, and 4 classes, distributed across 23 islands and archipelagos administered by seven sovereign nations and spanning roughly 37° to 62° S. Of the 886 taxa, 55.9% are native, 11.9% are endemic to the islands, and 33.4% are alien; the categories sum to more than 100% because 17 taxa carry two phytogeographic origins across their range. Richness varies over two orders of magnitude among islands, from 387 taxa in the Falkland/Malvinas Islands to three in the South Orkney and South Sandwich Islands. Every record is traced to its bibliographic source, and an accompanying change log documents each correction applied during compilation. The dataset supports analyses of island biogeography, endemism, and plant naturalization toward the southern limit of vascular plant distribution, and provides a taxonomically harmonized baseline against which future floristic change can be measured.