 "L. sonderi" is most closely related to "L. dubia" and it has even been described as a variety of "L. dubia" in the past.Johannes Mildbraed was the first person to reduce "L. sonderi" to a variety of "L. dubia" in his 1908 taxonomic monograph on the Stylidiaceae in which he noted he could not find any significant difference between "L. sonderi" and "L. dubia" to maintain the separate taxonomic treatment of the two species.Later studies have considered the species to be distinct.