Traditional leafy vegetables (LFT) are plants whose leaves are used and consumed by local human populations. Africa is an enormous reservoir of diversity for those vegetables which participate to food security, nutrition and monetary income in both rural and urban areas. The leafy vegetables are rich in fibres, vitamins and minerals. But intensive and repeated harvesting of the LFT in Africa results in their increasing rarity. Among endogenous leafy vegetables recorded in Benin, Sesamum radiatum Schumach. & Thonn. (Pedaliaceae) is a species commonly consumed by many ethnic groups. During plant development, quantitative and qualitative modifications occur, such as an increase in stem size and the production of leaves, flowers, fruit and grains To contribute to a better understanding of the breeding system and phenology for in situ and ex situ conservation of S. radiatum, we conducted both on-station and on-farm experiments. The on-station experiment was conducted at the International Institute of Tropical Agriculture in Abomey-Calavi in South Benin ( E) to study the phenology, the floral biology, the reproductive system and the insects visiting the flowers of the species .The on-farm experiment was carried out in Savè, in central Benin ( E) to study exclusively the floral biology and the insects visiting the flowers of the plant in its natural biotope. We studied plant phenology, anthesis, floral morphology and structure, pollen viability, the reproductive system and the insects visiting flowers. Data was analysed by using simple descriptive statistics (percentages, means, etc.) to characterise the species specific traits that are available in summary tables. In order to determine the reproductive system of the species, four pollination tests, (lot 1 = natural pollination (control); lot 2 = natural autopollination with flowers of the same plant; lot 3 = manual autopollination on castrated flowers with pollen from the same plant; lot 4 = natural allopollination on castrated flowers within pollen from other plants), were carried out. The pollination rate data was linearised and analysed with an ANOVA. Student-Newman-Keuls tests were used to test for significant differences between pollination treatments. Results indicated that S. radiatum is a facultatively allogamous hermaphrodite plant with a pollen/ovule ratio equal to 66.1. Regarding the phenology of this species, plant development occurs in 75 days with four development phases. The first phase lasts for seven days with plant height of 22.2 ± 4.6 mm, the second phase takes 32 days (39 days after plant rising) and the plant height is 226.0 ± 8.9 mm, the following phase extends on six days with a plant height of 675.0 ± 33.8 mm. The fourth phase stretches out to 28 days and the plant height reaches 810.0 ± 21.0 mm. Blooming period ranges from 4h00 to 6h00 with flowering peak at 6h00. Flowering was initiated 56 days after seedling emergence and most of the flowers (98%) appeared 71 days after seedling emergence. Insects encountered on open flowers were mostly hymenopterans, Lasioglossum duponti (Vachal), Apis mellifera L., Amegilla sp., Amegilla acraensis Fabricius and Xylocopa sp followed by dipterans, Paragus borbonicus Macquart, Eurycarenus sp. Some insects like Apis mellifera visited the flowers early in the morning (6h00 and 9h00) whereas others such as Xylocopa sp visited the flowers all day long. High synchrony in flowering times among plants suggests that the rate of allogamy in S. radiatum may be high.