Pileus: often viscid, often brightly and unusually colored. Look
For remnants of the cortina along its edge.
: a "cortina" – a membranous veil (see photographs under
), but sometimes membranous (Singer
Stipe: viscid, often bulbous, "ring zone" of remnants of the cortina often present
Stature: Tricholomatoid - Naucorioid –Armillarioid (?)
: mycorrhizal, therefore associated with trees, especially conifers and shrubs (Largent
Basidiospores: rusty brown and warty or wrinkled, inamyloid
Cystidia: sometimes present, but usually absent
Spore Print: rusty brown
Lamellae: variously attached, often colored even before spore production, then becoming rust brown.
Lamellar Trama: regular
In the field look carefully at the stipe to see if spores have colored the remnants of the cortina, which often disintegrates. If a little Cortinarius is coming up under a big Cortinarius you often can see the rust brown spores on the cap of the little guy.
Looking at the description of the Microcharacters and the Field characters above you'd think that it this would not be an easy genus to recognize. According to Smith, 1949, Cortinarius is a "difficult genus to describe, but easy to recognize." Cortinarii are pretty mushrooms. Note, for instance, the viscid (sticky) pileus and stipe. No dull, lifeless surfaces for these guys.
The cortina remains the key character. Always look for it.
The cutis and/or trama often react to hydroxide applications by changing color (www.mycokey.com)
There are over 500 species in North America (Bessette et al., 1997)