This species is characterized by its sometimes rather robust habit, well developed stipules with laciniate or glandular margins and a ligulate appendage with glands at its tip, often well developed leaves, pedunculate paniculiform inflorescences with cymose branches, reduced bracts, and medium-sized flowers and fruits. It is variable in the shape, size, and degree of toughness of the leaves, the size of the stipules, the degree of development of the petioles, and the size of the flowers and fruits. Steyermark (1974) circumscribed Rudgea hostmanniana somewhat narrowly, with the plants with more more tough-textured, often smaller leaves and smaller stipules separated in Rudgea bolivarensis, Rudgea corocoroensis, and Rudgea maypurensis and the plants of Trinidad and Tobago considered a separate subspecies. Howard (1989) did not taxonomically separate the plants of Trinidad & Tobago from the plants of continental South America, and formally synonymized the variety Steyermark recognized for these. The species Rudgea merumensis is also similar, and was separated by Steyermark but may fall within Zappi's circumsciption of Rudgea hostmanniana.
Zappi (2004) circumscribed Rudgea hostmanniana quite broadly, and synonymized the other three species that Steyermark (1974) recognized; she did recognize two subspecies, Rudgea hostmanniana subsp. hostmanniana, widely distributed and more commonly collected, and Rudgea hostmanniana subsp. maypurensis. Steyermark separated Rudgea maypurensis by its distinctive rather small shiny subsessile leaves, its quite short stipules with the sheath portion hardly expanded, its smaller fruits, and its habitat in savannas and on low granite outcrops (lajas) in southern Colombia and Venezuela. In contrast Rudgea hostmanniana has well developed stipules, medium-sized to large dull leaves, developed petioles, larger fruits, and a distribution in evergreen to semideciduous forest on various substrates but not granite outcrops.
Lachenaud et al. (2022) analyzed Rudgea hostmanniana and similar species in detail, and concluded by circumscribing this species more narrowly, and more similarly to Steyermark. They presented a table of distinguisihing morphological features, and again recognized Rudgea maypurensis, Rudgea billietiae, and Rudgea bolivarensis as distinct species. They also discussed Rudgea hostmanniana subsp. freemanuii (as "freemannii") of northern Venezuela and the Antille, but did not arrive at a conclusion about its taxonomic status.