Cladodes (also called cladophylls or phylloclades) are shoot systems in which leaves do not develop; rather, the stems become flattened and assume the photosynthetic functions of the plant. In asparagus (Asparagus officinalis; Asparagaceae), the scales found on the asparagus spears are the true leaves. If the thick, fleshy asparagus spears continue to grow, flat, green, leaflike structures called cladodes develop in the axils of the scale leaves. The presence of cladodes in unrelated desert angiosperm families is an excellent example of convergent evolution, or the independent development of the same characteristic in unrelated taxa.