Abstract
Two new species of Polyporales, Cerrena caulinicystidiata and Polyporus minutissimus, are illustrated and described on the basis of morphological studies and phylogenetic analyses from southern China and Vietnam. C. caulinicystidiata is characterized by annual, resupinate, sometimes effused-reflexed basidiocarps, greyish orange to brownish orange pore surface, irregular pores (3–8 per mm), a trimitic hyphal system, pyriform to ventricose cystidia, and subglobose basidiospores 3.2–4.5 × 2.8–3.5 µm in size. P. minutissimus is characterized by annual, solitary, fan-shaped with a depressed center or infundibuliform basidiocarps, obvious black stipe, cream to buff yellow pileal surface with glabrous, occasionally zonate and radially aligned stripes, angular pores (6–9 per mm), a dimitic hyphal system, and cylindrical basidiospores, 5–9.2 × 2.2–4 μm. Detailed descriptions and illustrations of the two new species are provided. The differences between the two new species and their morphologically similar and phylogenetically related species are discussed.