In botany, the reproductive structure of the conifers and cycads; also known as a strobilus. It consists of a central axis surrounded by numerous, overlapping, scalelike, modified leaves (sporophylls) that bear the reproductive organs. Usually there are separate male and female cones, the former bearing pollen sacs containing pollen grains, and the larger female cones bearing the ovules that contain the ova or egg cells. The pollen is carried from male to female cones by the wind (anemophily). The seeds develop within the female cone and are released as the scales open in dry atmospheric conditions, which favor seed dispersal.
In some groups (for example, the pines) the cones take two or even three years to reach maturity. The cones of junipers have fleshy cone scales that fuse to form a berrylike structure. One group of angiosperms, the alders, also bear conelike structures; these are the woody remains of the short female catkins, and they contain the alder fruits. In zoology, cones are a type of light-sensitive cell found in the retina of the eye.
1. A skin sore caused by chafing.
2. Abnormal swelling of plant tissue caused by insects or microorganisms or injury.
Abnormal outgrowth on a plant that develops as a result of attack by insects or, less commonly, by bacteria, fungi, mites, or nematodes. The attack causes an increase in the number of cells or an enlargement of existing cells in the plant. Gall-forming insects generally pass the early stages of their life inside the gall.
Gall wasps are responsible for the conspicuous bud galls forming on oak trees, 2.5–4 cm/1–1.5 in across, known as “oak apples”.