A palynological study of natural honeys from the Bongaigaon district of Assam, northeast India

Palynological examination of 18 honey samples (BG-1-18) procured from nine localities in the Bongaigaon District, Assam, India, produced a assemblage of pollen in terms of quantity and diversity. According to palynological assessment of the honey samples, 12 were unifloral (five in terms of Brassica campestris, two from Elaeocarpus rugosus and one each from Mimosa pudica, Xanthium strumarium, Syzygium cumini, Salmalia malabaricum and Meliaceae). Six were multifloral; the dominant taxa include Mimosa, Brassica, Coriandrum, Ziziphus mauritiana and Salmalia. Taxa such as Cassia fistula, Acacia catechu, Toona ciliata, Butea monosperma, Lagerstroemia parviflora, Lamiaceae, Malvaceae and Oleaceae were minor sources of nectar and bee forage, as indicated by low frequencies of their pollen. The numerous pollen types and their diversity show that bees travel considerable distances to collect nectar for honey production. The study could be helpful in evaluating the allergenicity of some honeys in the area of investigation, causing hay fever, asthma, dermatitis and other disorders, where composition is mainly of Compositae allergic' pollen such as Xanthium (BG-2; 57.78%; unifloral) and Eupatorium (BG-4; 37.64%; unifloral).