Blusher

The blusher is the common name for several closely related species of the genus "Amanita". A. rubescens, found in Europe and eastern North America, and A. novinupta in western North America. Both their scientific and common names are derived from the propensity of their flesh to turn pink on bruising, or cutting.
The mushroom is edible and tasty, sought for in several European countries. It is readily recognizable by its pinkish color on the bottom of the stem. It is avoided by novice mushroomers as without knowledge it can be confused with deadly poisonous species.
Description.
The European blusher has a reddish-brown convex pileus (cap), that is up to 15 cm across, and strewn with small cream-coloured warts. It is sometimes covered with an ochre-yellow flush which can be washed by the rain. The flesh of the mushroom is white, becoming pink when bruised or exposed to air. This is a key feature in differentiating it from the poisonous false blusher or panther cap "(Amanita pantherina)", whose flesh does not. The stipe (stem) is white with flushes of the cap colour, and grows to a height of up to 15 cm. The gills are white and free of the stem, and display red spots when damaged.
The ring is striate (i.e. has ridges) on its upper side, another feature distinguishing it from "Amanita pantherina".
The spores are white, ovate, amyloid, and approximately 8 by 5 µm in size.
The flavour of the uncooked flesh is mild, but has a faint acrid aftertaste. The smell is not strong.
The mushroom is often attacked by insects.
Distribution and habitat.
It is common throughout much of Europe and eastern North America (in the latter region there are at least three different species that fit into the name "Amanita amerirubescens") growing on poor soils as well as in deciduous and coniferous woodlands, appearing from June through to November in the UK. It has also been recorded from South Africa, where it is thought to have been accidentally introduced with trees imported from Europe.
In eastern North America, "Amanita rubescens" is frequently parasitized by "Hypomyces hyalinus". Parasitized fruiting bodies are extremely difficult to recognize unless they occur in conjunction with healthy ones, although some retain the "blushing" characteristic of the species.
"Amanita novinupta".
A species found in the western U.S., only recently formally described and until then frequently misidentified as "A. rubescens"; see MykoWeb - Fungi of California - "Amanita novinupta" for details.
Other species.
Closely related species include "Amanita brunneolocularis", "A. orsonii", "A. rubescens" var. "alba", and "A. rubescens" var. "congolensis".
Uses.
Both "A. rubescens" and "A. novinupta" are edible when cooked. European "Amanita rubescens" is known to contain a hemolytic protein in its raw state; it is unknown whether North American "A. rubescens" and "A. novinupta" are similarly toxic when eaten raw. This protein is destroyed by cooking, so it is important to cook this mushroom before eating.
"Amanita novinupta" is highly regarded as a choice edible in the region in which it is found. However, the edibility of blusher species other than "A. rubescens" and "A. novinupta" has not been established and experimentation is not advised.