• Truffles grow beneath oak trees.James And James/Brand X Pictures/Getty Images
  
  Mushrooms are the fruit structures of a large variety of fungi. Some kinds of mushrooms grow from the soil in lawns and pastures, and other types sprout from fallen logs. Some mushrooms are culinary delights, while others are poisonous. You can even find mushrooms used for textile dyes, and shelf fungi used for artistic carvings or paintings. Some of the most delicious and attractive edible mushrooms are those that grow in oak trees.
  
  

Truffles

• Truffles (Tuber melanosporum vittadini) are subterranean mushrooms prized in gourmet cooking as a unique, earthy-smelling delicacy. Truffles have specific habitat needs, growing only near the roots of specific types of trees, primarily oaks. While truffles cannot be cultivated with the same precision and productivity as ordinary agricultural crops, commercial truffle providers plant groves of oak trees, particularly of the English oak or truffle oak species (Quercus robur), first inoculating the roots of the tree saplings with truffle spores, the functional equivalent of a mushroom's seeds. Truffles grow where the spores come in contact with a micro-thin root of the oak tree. The two species grow together, in a symbiotic relationship.
  
  

Hen of the Woods

• The hen of the woods (Grifola frondosa), also called the maitake or sheepshead mushroom, most commonly grows at the base of large oak trees, according to mycologist Dave Fisher, author of "Edible Wild Mushrooms of North America." The hen of the woods is a prized edible and medicinal mushroom frequently found in stands of oak trees in the eastern United States. A single specimen can easily weigh 20 lb., and one oak tree may produce 100 lb. of this mushroom. Hen of the woods mushrooms grow as a cluster or colony of beautifully ruffled ivory to tan caps, edged in darker tan to purple. The underside of each cap is marked by pores, or descending tubes that end in small openings on each cap's lower surface. This helps to distinguish the hen of the woods from other similarly shaped mushrooms that have gills or vertical paper-like dividers on the undersides of their caps.
  
  

Chanterelles

• The chanterelle (Cantharellus cibarius) is a bright-yellow to orange or egg-yolk colored funnel-shaped mushroom found all summer season long beneath hardwood trees, most particularly in stands of oaks (Quercus spp.), according to the Ohio State University Extension. The California golden chanterelle grows exclusively in a symbiotic relationship with the roots of live oak trees (Quercus virginiana). Chanterelles are edible mushrooms highly valued by chefs for their peppery, fruity flavor. The underneath of the chanterelle cap is marked by deep, wavy ridges similar to gills. Exercise caution in the wild harvest of chanterelles and be certain of positive identification before you eat them, as there are several poisonous mushrooms with similar appearance.