Cross-section through the leaf of a leek. The spongy tissue, called mesophyll, is typical of leaves. Here the leaf shown magnified is just 1.2 millimeters thick.
Images excerpted from Wonders of the Plant Kingdom: A Microcosm Revealed, © Wolfgang Stuppy, Rob Kesseler & Madeline Harley/Papadakis Publisher.
Published in the United States by the University of Chicago Press.