Anton Kerner has shown that crowded inflorescences such as those of Compositae and Umbelliferae are especially adapted for geitonogamy.
I, Branch with male (a) and female (b) inflorescences; 2, bract with three male flowers; 3, bract with three female flowers; 4, infrutescence; 5, fruit.
Spikelets unisexual, male and female in separate inflorescences or on different parts of the same inflorescence.
In the conifers proper the female reproductive organs have the form of cones, which may be styled flowers or inflorescences according to different interpretations of their morphology.
The male and female inflorescences have the form of simple or paniculate spikes.
Numerous circular pits occur on the concentric ridges of the depressed and wrinkled crown, marking the position of former inflorescences borne in the leaf-axil at different stages in the growth of the plant.