In this paper, we report a study of the mating system and gene flow of Symphonia globulifera, a hermaphroditic, mainly bird-pollinated tree species with a large geographic distribution in the tropical Americas and Africa.

Using three microsatellites, we analysed 534 seeds of 28 open pollinated families and 164 adults at the experimental site ‘Paracou’ in French Guiana. We observed, compared to other tropical tree species, relatively high values for the effective number of alleles.
Significant spatial genetic structure was detected, with trees at distances up to 150 m more genetically similar than expected at random. (lire la suite…)

Palm life form and species found in the main ecosystems of the 3 Guianas (savannahs, herbaceous swampy savannahs, forests) are described and listed respectively.

Stems are erect, creeping, climbing or suterranean, and palms are solitary or clustered. Leaf blades are entire, irregularly or regularly divided into pinnae which are regularly disposed in one plane or clustered or oriented in several directions from the rachis.

All these characters are considered in relation to habitat. Small, clustered palms with entires or divides leaves predominate in shady understory. (lire la suite…)

Une espèce nouvelle de Passiflora (P. vescoi Rignon) est décrite de Guyane française. Elle fait partie du sous-genre Astrophea au sein duquel elle est proche de P. costata. (lire la suite…)

Spadix temperature was measured in three species of Philodendron: P. acutatum, P. pedatum and P. solimoesense.

These species showed two different patterns of spadix temperature during their flowering cycle. In P. acutatum and P. pedatum (subgenus Philodendron), the spadix warmed up twice during the beginning of each flowering night with a temperature not significantly different from that of ambient air between the two peaks. (lire la suite…)

The pollination of Philodendron solimoesense (subgenus Meconostigma) was studied in four populations of French Guiana. Flowering is asynchronous within each population during July, and the flowering cycle is a 2-d process.

Numerous insects visit Philodendron inflorescences, but the main pollinator seems to be Cyclocephala colasi (Scarabaeidae, Dynastinae).
(lire la suite…)