A unique cactus with scented and possibly bat-dispersed fruits: Rhipsalis juengeri

Rhipsalis juengeri was described in 1995 as an unusual representative of epiphytic cacti, forming more than 3 m long curtains, hanging from the canopy of the Atlantic Rainforest in eastern Brazil. At the apex of thin, pendant shoots, green-brownish berries are formed. We report here as a novelty for the Cactaceae that these berries are strongly scented, and present an odour analysis along with an olfactoric survey of fruits of about 50 species and varieties of the cactus tribe Rhipsalideae. The volatile blend of berries of R. juengeri is dominated by ketones, some of which are responsible for the characteristic blackcurrant-like scent, as is shown by GC-olfactometry. The odour and inconspicuous colour stand out among fruits of other epiphytic cacti that are thought to be consumed by birds. Fruit characters of R. juengeri and the flagellicarpic presentation indicate adaptation to chiropterochory.