A climb to the top of or one of many other volcanoes shows an important and remarkable change in vegetation; lower trees, which are covered in mush and sub-alpine meadows and swamps at the top, gradually replace high trees. A remarkable flower on higher altitudes is the Javanese edelweiss Anaphalis javanica, which only grows on volcanoes. This flower usually reaches four meters in height and is colored white-green because of its small hairs; the flowers are yellow with white. The peak of the volcano itself is bald, because of the last eruption in 1934.
The park also houses the biggest flowers in the world, the monstrous, flesh red flower of the parasite Rafflesia arnoldi and the two-meters-high flower-flames of Amorphophallus titanum.