Stoebe vulgaris is a dominant woody shrub in South African grasslands and savannas, widely recognized for its aggressive encroachment into degraded rangelands. Despite its ecological and economic significance, research on this species has historically been fragmented across fields such as taxonomy, ecology, control strategies, phytochemistry, and remote sensing. This systematic review synthesizes nearly a century of scientific literature (n = 106) to critically evaluate the scope, trends, and gaps in S. vulgaris research. Ecological studies reveal S. vulgaris preference for disturbed, nutrient-poor soils, and fire-prone systems, yet regional variation in environmental response remains poorly understood. While numerous control strategies have been tested, few link treatment outcomes to plant traits, site conditions, or long-term vegetation recovery. Emerging research on phytochemistry and remote sensing offers promising tools for management but are limited in scope and geographic coverage. Additionally, the species' taxonomic history has been complex. Recent genomic analyses identified S. vulgaris as part of the Seriphium plumosum complex and proposed dividing the broad concept into seven ecologically distinct species. While this clarification narrows the ecological and geographical characteristics of the problem species major challenges remain for ecological modeling, remote detection, and management approaches. Crucially, broader ecosystem-level impacts such as effects on biodiversity, soil, water dynamics, and herbivore movement remain understudied. We identify key research gaps and call for an integrated, ecologically grounded, and spatially comprehensive research framework to improve monitoring and control of S. vulgaris and to ensure the sustainability of South Africa's rangelands.