Summary:
Features include 1) resupinate growth on rotten wood, 2) dense, narrow, greenish spines on a loose white subiculum that has rhizomorphs, 3) spores that are elliptic or somewhat fusiform, yellow, with cyanophilic warts, 4) a monomitic hyphal system, the hyphae often encrusted, in some cases ampullately widened at the clamped septa.

Microscopic:
SPORES 8-10(12) x 3-4(5) microns, "subfusiform, obliquely tapering to apiculus", yellow, with thickened walls, with cyanophilic warts, contents usually with one oil droplet; BASIDIA 4-spored, 20-35(40) x 6-7 microns, clavate, basally tapering to a stem-like part of varying length, with basal clamp connection, small oil droplets in protoplasm, "basidia in young hymenia (i.e. near the apex of the aculei) pleurobasidial"; CYSTIDIA none; HYPHAE monomitic, 2-4 microns wide, when young thin-walled and smooth, "older hyphae in subiculum and rhizomorphs with somewhat thickened walls", "often encrusted, in some cases ampullately widened at septa", "hyphae in the sterile apical part of the aculei densely parallel", (Eriksson), SPORES 7.5-9 x 3-4 microns, elliptic, verrucose, inamyloid, yellow, cyanophilic, rather thick-walled; BASIDIA not seen, according to the literature 4-spored, 20-25(40) x 5-7 microns, with basal clamp connection; CYSTIDIA not seen; HYPHAE monomitic, 2.5-5(9) microns wide, thin-walled to thick-walled, "some incrusted and somewhat inflated", (Breitenbach)

Notes:
Kavinia alboviridis has been found in BC, ID, MB, NS, ON, PQ, AZ, CA, CO, CT, IA, MA, MI, NM, NY, OH, and TN, (Ginns(5)). It has also been found in Europe including Switzerland (Breitenbach). It occurs in Denmark, Sweden, and Finland, (Eriksson).