Table Mountain Pine ConeThe cone of Table Mountain Pine (Pinus pungens) from South Africa may look m

Table Mountain Pine ConeThe cone of Table Mountain Pine (Pinus pungens) from South Africa may look more like the end of a medieval weapon than a reproductive structure, but the cones of gymnosperms house seeds.Each scale on a pine cone typically holds 1-2 seeds fused to the top of the scale, with a small bract on the underside. The seeds each fall off with a thin sheet of the scale attached to it, acting as a wing. The wing allows the seed to fall a horizontal distance up to 3 times the vertical height of the tree on a windy day. This convergent evolution is similar in function to that of samaras, the winged seeds of angiosperms such as maples, and ashes. The cone scales close when there is high moisture content, depicted in picture. The outer surface of each scale that is visible when a cone is closed is called the apophysis. In the middle of the apophysis is a scar or protrusion called the umbo, which typically represents the first year’s growth of the cone. The umbo on Pinus pungens and other pines as well, grows into a stout protrusion or spike that makes it very uncomfortable to handle. Not very much has been written about the purpose of a protruding umbo, there does not appear to be any fitness gain. Dendrologist Dr. Richard Braham shared his humorous position on the origin of traits like protruding umbos, colored buds, and other diagnostic traits; their purpose is simply to help dendrologists identify the trees!-Greg AegisFurther Readinghttp://www.pinetum.org/Lovett/pinecones.htmhttp://www.ncsu.edu/project/dendrology/index/plantae/vascular/seedplants/gymnosperms/conifers/pine/pinus/australes/tablemountain/reproductive.htmlPhoto Cred“Botany Bill”http://blog.botanybill.info/?p=959 -- source link

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