Unformatted text preview: internode. Nodes and internodes are distinctive on twigs with or without their leaves attached. A leaf scar remains on the stem when leaves dehisce. The pattern of leaf scars is a species characteristic. The vascular bundles of the leaf petiole also leave bundle scars within the leaf scar. Each growing season, a ring of bud scale scars that protected the dormant terminal bud can be seen on twigs. This is one way to determine the age of a twig or branch. Lenticels are also more visible on twigs than on older stems where the bark patterns may mask them. As secondary growth continues, and branches increase in girth, the expansion of cork and bark eventually replaces the features found on twigs. Older branches take on the bark pattern associated with the specific species....
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- Fall '09
- RNA, secondary growth, Plant stem