I got a email inquire from a client asking why they had be-bee like structures on their White Pine trees. It was a reminder of botany 101 that we have two major groups of plants. One being angiosperms(flowering plants) and gymnosperms( Cone bearing plants).Seed ferns gave rise to the gymnosperms during the Paleozoic Era, about 390 million years ago.
Conifers produce flower-like structures in the early spring, but technically, no, they don't produce true flowers. Immature cones of conifer trees are short-lived structures that make a brief appearance during the months of May and June. Male pollen cones are round structures that range from hot pink to deep purple.Most people are familiar with conifer cones, although they tend to call all of them “pine cones.”
In common with other members of the class Gymnospermae, pine trees have no flower or fruit. Rather, the ovule (and later the seed) are "naked" (gymno = naked, in Greek) and are, in all members of the Pinaecae family, wedged between the scales of a woody "cone," so named because it is generally cone-shaped. The cone bearing the female gametes is larger and is commonly recognized simply as the pine cone, but also can be called the female cone or megasporangiate strobilus.
In some texts the name for the structure bearing the male gamete also incorporates the name cone, such as the "male cones" or "pollen cones," but these structures are clustered, are much smaller and deteriorate quickly. They really shouldn't be called cones, although there is not a good common term for them. These "male cones" are properly called microsporangiate strobili, which is not an easy common usage term. Also the term "catkins" (from cat tails) which is used in the case of the angiosperms doesn't describe them well and is not commonly used for gymnosperms. The pollen shed from the microsporangiate strobili is carried to the megasporangiate strobili (cones) by the wind. Pines are not pollinated by insects.
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Pine cones (herein referring only to the true female cones) have a peduncle (stem) which attaches to the branch (usually the upper branches) of the tree and this continues through the entire length of the cone as the rachis (axis). Multiple cone scales arise along the length of the rachis in a helical fashion to give the cone most its mass and characteristic external appearance. The cone scales each carry two ovules which usually develop into seeds on their ventral (the side closer to the distal end of the cone) surfaces. Hence these scales are also called ovuliferous scales or seed scales. Lack of pollination, genetic defects or other mishaps may result in sterile (or no)seeds. A smaller bract scale subtends and merges with the cone scale dorsal surface and is quite inconspicuous. (The bract scales can be clearly seen on Douglas fir cones because they are longer than the seed scales and protrude as the familiar trident tags.)
The seed scale has two parts. The first is the umbo which is the first year's growth and distal most portion of the the two year old cone's scales. The umbo in many of the yellow pines (Diploxylon) has a sharp spike ("prickle"). The second part of the seed scale grows in the second year (after fertilization) of the seed scale and is called the apophysis. Pine cones reach maturity in two years in almost all species.