About Drosera erythrorhiza subsp. collina N.Marchhant & Lowrie
Drosera erythrorhiza, commonly called the red ink sundew, is a perennial tuberous carnivorous plant in the genus Drosera that is endemic to Western Australia. It grows in a rosette form, and is distinguished from other species in section Erythrorhiza by its many-flowered cymose inflorescences that can hold up to 50 individual flowers. It was first described by John Lindley in his 1839 publication A sketch of the vegetation of the Swan River Colony. In 1992, N. G. Marchant and Allen Lowrie described three new subspecies of this species, also creating the autonym D. erythrorhiza subsp. erythrorhiza. Subspecies were separated from this variable species primarily based on leaf morphology and distribution. This taxon, D. erythrorhiza subsp. collina, is named for its native hilly habitat, and typically produces more leaves of varying shapes within a single rosette. D. erythrorhiza subsp. erythrorhiza has fewer, wider leaves compared to D. erythrorhiza subsp. magna, which has larger (wider) leaves and often produces more of them. The final subspecies, D. erythrorhiza subsp. squamosa, was originally described by George Bentham in 1864 at the species rank as Drosera squamosa; Marchant and Lowrie later reduced it to subspecies rank under D. erythrorhiza. Subspecies squamosa differs from subsp. erythrorhiza by its red leaf margins, which are caused by dense red tentacles. Earlier, in his 1906 taxonomic monograph of the Droseraceae, Ludwig Diels introduced a new variety: D. erythrorhiza var. imbecilla. In 1999, Jindřich Chrtek and Zdeňka Slavíková proposed an alternative competing taxonomy, arguing that all tuberous Drosera (the entire Drosera subgenus Ergaleium) should be reclassified into Johann Georg Christian Lehmann's 1844 genus Sondera, which had previously been reduced to a synonym of Drosera. In this reclassification, Chrtek and Slavíková elevated Marchant and Lowrie's subspecies to full species rank, establishing Sondera collina, S. erythrorhiza, S. magna, and S. squamosa. This reclassification is not widely followed by the botanical community.
