Mushrooms are called as chattraka as they look like an umbrella. Another synonym of mushroom is Sama-svedaja Shaka which means plant produced by sweat or hot moisture.
According to the text Bhavaprakash, anything which originates from sweda/moisture is toxic to the body (and vitiates all the 3 doshas), but the mushrooms which grow in a scared place, or on the stem of trees or on bamboos is less toxic and less harmful, making them suitable for eating.
Following are the properties of edible mushrooms -
Rasa (taste): Madhura (sweet)
Guna (properties): Guru (heavy), Snigdha (unctuous), Picchila (slimy)
Virya (potency): Shita (cold)
Ideally, mushrooms are beneficial for people suffering from shosha (emaciation), daaha (burning sensation) and Amlapitta (some types of gastritis). But because of its toxic nature it is not suitable for regular intake.
PS : This post is for information purpose only, it does not promote self medication. Please contact your ayurveda physician for more details.