A purple mushroom

This little mushroom was growing alone on grass under oak trees near my home. It has a very nice dark purple color that is reminiscent of aubergines and has a nice chubby hemispheric cap that makes it a very cool specimen. Unfortunately it was damaged and very young when I found it.

Date: 07/17/2011
Location: Rollins Park, Rockville, MD
Habitat: Solitary, growing on grass under oak trees

Measurements
Pileus diameter - 23.8 mm
Pileus height - 16.5 mm
Stipe lenght - 26 mm
Stipe diameter at apex - 12.5 mm
Stipe diameter at middle - 12.5 mm
Stipe diameter at base - 11.5 mm


Description
Pileus - Purple, glabrous, dull, round, hemispheric. Margin is incurved. Smell is fruity and aromatic. Flesh is white. Taste is very bitter. Flesh does not stain when bruised.
Hymenium - White pore surface with tubes 1 mm long. Does not stain when bruised.
Stipe - solid, white flesh, purple cuticle, central, slightly tapered, inserted, does not stain. No ring or volva.
Spore print - not obtained.

Impressions

This specimen looks like a Tylopilus plumbeoviolaceous. Apart from the odor, which I found to be quite agreable, the rest of the observed characteristics fit with Roody's description (p. 341). The mushroom is very bitter and is described as being inedible (I wonder who would try eating it anyway).  This is in contrast with the somewhat similar T. eximius (Lilac-brown Bolete), which is considered by some as being edible (although there are some reports of poisoning caused by this mushroom). The speckled stipe and  non-distinctive flavor allows one to easily distinguish it from T. plumbeoviolaceous. Other lookalikes which are also bitter are T. rubrobrunneus (Reddish brown bitter Bolete) and T. violantinctus (Pale Violet Bitter Bolete). The former develops olive-brown stains on the stalk and the later has a pale purplish to grayish violet or pale brown pileus.


References
Falcon Guide to North American Mushrooms, page 380
Mushroooms of West Virgina and the Central Appalachians, page 341