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 58 champion evergreen DHJanzen100369.jpg high resolution
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| On the one hand, a cactus is the champion evergreen, since it is always green and the oldest green parts are as old as the plant itself. But, that is cheating because it is the stem, rather than a leaf. In this image is a greenhouse potted plant of Welwitschia (Gnetaceae, a Gymnosperm) from southern Africa, the champion evergreen. This plant from very arid desert-like circumstances has just two leaves. Strap like and achieving up to several meters in length, they are continually added to at the base and never drop off. The actual leaf tissue may be only 5-15 years of age on a given plant (since the tip finally dies and falls off), but the leaf itself as a structure is as old as the plant, which may be many decades to centuries. | ||
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