Spring Cones!

Conifers, the trees with needle like leaves are well known for their cones. The female woody cone is likely the cone that is most commonly observed. The female woody cones are often gathered seasonally and used as decorations. The male cones are also scale like and grow in dense clusters. On windy days in spring and the beginning of summer small plumes of yellow pollen can be seen arising from the male cones. The pollen grains are carried in the wind to the female cones. At the base of each scale on the female cone there is an ovule which contains the female egg cell. If fertilization of the egg cell is successful a seed will form at the base of the scale. It can take up to two years for the seed to develop. In the autumn of the second year the seed and the surface tissue of the scale separate to form a winged structure. The winged seed can be released in the wind to establish itself as a new seedling.

Below are four images of the male and female cones on a Monterey Pine tree in spring. The first two images are the male pollen cones. The second two images are the early stages of the female cone. The female cone is a distinctive scale like fleshy purple. The female scales will open temporarily to receive the male pollen. Once the male pollen grains have been received the scales on the female cone will reclose and a hard woody cone will develop over time. One of the distinctions between the Gymnosperms (conifers and cycads) and the angiosperms (flowering plants) is the ‘naked seed’. The naked seed of the gymnosperms is not enclosed within an ovary.