Female cannabis flowers are distinguished by their white hairs, which first appear in pairs at the top of the stem and branches and at the internodes where branches emerge from the stem. These hairs will increase in number, thicken into clusters and change colour from white to orange as flowering progresses.
Male cannabis flowers may be recognized by the pairs of tiny pods (initially, smaller than a match-head) in the same locations. They too will quickly increase in number. Soon after forming, these pods will open into mature male flowers which will then distribute pollen.