Leaves alternating on the stem. One at a node.
Leaves
opposite on the stem. Two at a node.
Leaves whorled on the stem. Three or more at a node.
Leaf arrangements on the stem
Illustrations by Marina Smelik.
Leaves can be attached to the stem in one of three ways: alternating, opposite or whorled. The leaf arrangement is fairly consistent, but you may find a few plants that exhibit more than one type of leaf arrangement. When determining how the leaves are attached to the stem, don't look at leaves near the tip of the stem since those leaves may be crowded together and confuse you. Rather, look farther down the stem where the leaves are well spaced to determine the leaf arrangement.