What type of leaf anatomy is characteristic of C4 plants?

Kranz anatomy is the characteristic leaf anatomy of C4 plants. The name comes from the German word Kranz, meaning “wreath,” because each vascular bundle is typically encircled by a ring of bundle-sheath cells, which is itself surrounded by mesophyll cells.

This arrangement supports C4 photosynthesis. Mesophyll cells first capture carbon dioxide with PEP carboxylase, producing four-carbon compounds such as malate or aspartate. These compounds move into bundle-sheath cells, where they release concentrated carbon dioxide for RuBisCO. The higher carbon-dioxide concentration reduces photorespiration, especially in hot, bright environments.

A common mix-up is treating “bundle sheath” as the answer. Bundle-sheath cells are a component of Kranz anatomy, not the name of the complete anatomical pattern. Palisade and mesophyll describe cell or tissue types found in leaves more generally. Kranz anatomy is strongly associated with C4 plants, although a few C4 species use single-cell carbon-concentrating systems without the classic rings. Hatch and Slack elucidated the C4 pathway in the 1960s.