Figure 4.24 Left. Root of clover (Trifolium subterraneum) colonised by an arbuscular mycorrhizal fungus. The fungus has formed thick entry hyphae in the epidermis before spreading through the cortex cells, forming an arbuscule (A) in many cortex cells and some vesicles (V). Roots were cleared (to make them transparent) and then stained with Trypan blue. Right. Root of leek (Allium porrum) colonised by indigenous mycorrhizal fungi showing hyphae, arbuscules and many large vesicles. (Photographs courtesy M. Brundrett)