This species is characterized by its shrub habit, well developed stipules that are shortly fused at the base, narrowly elliptic leaves, few-flowered cymose inflorescences, corolla tubes 12-15 mm long, and hirtellous capsules. It was described based on a few specimens from a poorly known, unusal region,w tih sclerophyllous scrub vegetation, and considered endemic to this site. Ladenbergia siranensis is similar to Ladenbergia acutiffolia, which grows as a tree with larger inflorescences, and Ladenbergia shawistigma, with smaller inflorescences.