La sécrétion des nectaires extra—floraux de quelquesIngaen Guyane française

Summary The Inga genus (Leguminosae-Mimosoideae), endemic of tropical America, is widely found in French Guiana. Most of species live in rain forest and oftenly have a pionner behaviour. On the rachis, in each point of pinnae insertion, the pinnate leaves present a cup—shaped nectary whose structure is very specialized. The functioning and the role of nectaries of four different species (l. pezizifera I. sertulifera, I. stipularis and I. thibaudiana) were studied on two guiana sites. An analysis of secretion rhythms puts in a prominent a pick at six o'clock which can change depending of the environment. A study of nectaries activity shows a nectar production just as well on new leaves as on oldier, with an independent functioning of each nectary for a same leaf. The analysis of nectar's composition allowed to reveal the presence of sugars, amino—acids and lipids for each Inga. Many ants are present on the plant and harvest the exuded nectar. However, it seems that the ants—plant relation is a diffuse type.