The Circle of Life

Anacardium occidentale, like all other angiosperms, has a life cycle that includes "alternation of generations." This means that during its life time, the plant alternates between a dominant diploid sporophyte generation and a haploid gametophyte generation.

 

Within the flower's anthers (male parts), are thousands of diploid spores called microsporangium. These then divide by meiosis to produce a haploid pollen grain. Within the flower's carpals (the female parts), a single diploid macrospore is contained in the ovule. This divides by meiosis to give four megaspores, though only one survives. Since they produce different kinds of spores, angiosperms are considered heterosporous. Then the pollen grain (containing the sperm), lands on the stigma to pollinate the flower. It is here that the pollen grain germinates and develops into the zygote to begin the next sporophyte generation.

     

 

In many angiosperms, flowers are pollination is helped along by insects, the wind, other organisms, etc. Anacardium occidentale is affected by all of these factors, however studies have shown that in this particular tree, wind is less of a factor than would be expected. According to the Journal of Agricultural Science, issue number 0021-8596, studies suggest that the primary pollinator of cashew trees is surprisingly the honey bee, Apis mellifera.To learn more about Apis mellifera, click here to visit a fellow student's web page!