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 40 tendrils for climbing DHJanzen100351.jpg high resolution
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| This image contains two ways that leaves have been modified evolutionarily into climbing structures. In the lower left there is a Costa Rican bignoniaceous vine with trifoliate compound leaves. However, the central leaflet on the leaf has become a trifid (examine its tip) tendril that will wrap around whatever it contacts to support the growing, elongating vine. But note also that while this works very well to bind to small stems, it cannot begin to reach around the large tree stem in the image. In the center is a grape vine (Vitaceae) that has solved the problem of climbing a large tree. It has modified a leaf into a tendril with the ecological equivalent of suction cups on the end. The tendril extends out over the surface, the flat area at the tip expands on a microscale into the tiny cracks in the bark and then hardens, and as the tendril dies it dries and shrinks, pulling the vine tightly against the tree trunk. Such a mechanism allows the vine to climb straight up a smooth vertical surface and not be killed by later expansion of the tree trunk. | ||
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