Nepenthes tobaica is a species of pitcher plant endemic to Sumatra. It is particularly abundant near Lake Toba, for which it is named, where it can be found in practically all slopes in the mountainous region. The species has pitchers with a simple morphology, with a small peristome, angled lid and somewhat bulbous lower half. The lower pitchers feature a set of subtle wings running down the sides. The pitchers display remarkable variation in colour and patterning, even in plants within the same immediate vicinity.
I observed the species around Lake Toba, mostly in the steep hills surrounding the caldera. The plants mostly grow terrestrially on slopes and cliffsides, especially amongst Gleichenia ferns but also in open Casuarinaceae forest. The plants seem to prefer a high level of light.