Stipitate hydnums of the southern United States 1: Phellodon mississippiensis sp nov.

During a general survey of fleshy fungi from Mississippi, an undescribed Phellodon species was observed in the Tombigbee National Forest at the same location over a two-year period. No other studies of the stipitate hydnums are available for the midsouthern states that directly compare with the new species. Molecular sequence data of P. mississippiensis were distinct from other Phellodon spp. of the southeastern United States. The highly fused (concrescent) basidiomata of P. mississippiensis are found under mixed hardwoods and associated pines. The light tan to light rust (orange) or salmon color on the marginal spines and along the margin of the small (<= 5 cm broad) stout spongy tomentose basidiomata makes this species distinct. The presence of rare clamp connections was observed in the trama hyphae. However, identification of P. mississippiensis can be complicated by its concrescent nature and the indeterminate growth forms caused by environmental conditions. Morphological characters and results from the phylogenetic analysis are included in the species description.