the lid is a vivid red, making the plants particularly easy to spot amongst other vegetation. Ecology Nepenthes tobaica is endemic to Sumatra. Its natural range was once thought to stretch from the Gayo Lands of Aceh in the north to Tarutung in the south. Towards the end of the 20th century, new locations of this species were discovered further south. These include Mount Sorik Merapi and a unique high altitude peat swamp habitat near Lake Kerinci in Jambi. Charles Clarke cites its altitudinal range as 380 to 1800 m above sea level, with a habitat near the port town of Sibolga constituting the lower extreme and Mount Pangulubao the upper extreme. However, according to Matthew Jebb and Martin Cheek, N. tobaica can grow at altitudes of up to 2750 m. This species typically grows terrestrially in exposed areas. Nepenthes tobaica commonly grows in forest edges, where it is often sympatric with species of Leptospermum and Rhodomyrtus. Nepenthes tobaica is very abundant in the Lake Toba region, to the point where it is "difficult to avoid seeing it there". N. tobaica is also known to grow in high altitude peat swamp forest near Lake Kerinci, at an altitude of 1100 m. At this location, the species grows alongside N. ampullaria, N. gracilis, N. mirabilis, N. reinwardtiana, and N. spathulata. The Nepenthes species and hybrids at this site exhibit high levels of introgression. The vegetation is dominated by species of the genera Rhododendron and Melastoma, as well as orchids and ferns. It is very stunted and dense, with few trees exceeding 3 m in height. It is somewhat reminiscent of the highland heath forests around Bareo in Sarawak, Borneo. The conservation status of N. tobaica is listed as Least Concern on the IUCN Red List based on an assessment carried out in 2018. Pitcher infauna The pitchers of N. tobaica play host to a wide variety of infaunal organisms. The mite species Creutzeria tobaica was described from the pitchers of a Javanese Nepenthes identified as N. tobaica. However, N. tobaica has not been recorded outside of Sumatra. Related species In 2001, Charles Clarke performed a cladistic analysis of the Nepenthes species of Sumatra and Peninsular Malaysia using 70 morphological characteristics of each taxon. The following is a portion of the resultant cladogram, showing part of "Clade 6". The sister pair of N. angasanensis and N. mikei has 79% support. The pitchers