Five taxa that morphologically resemble Astrocystis and Collodiscula were collected on bamboo culms from Guizhou, Hainan and Yunnan provinces in China. Based on morphology and molecular analyses (combined ITS, RPB2, β-tubulin and α-actin genes), these species were identified as Astrocystis cocoes (a new record to China), A. bambusicola, Collodiscula japonica and two new species (A. multiloculata and C. lancangjiangensis). Astrocystis multiloculata can be distinguished from other Astrocystis species by its superficial stromata containing many perithecia and larger ascospores (19–25 × 7–11 μm). Collodiscula lancangjiangensis has larger ascospores (26–36.5 × 5–7.5 μm) than those of the most similar species C. fangjingshanensis (19–25.5 × 4.5–6 μm). It also has larger, 3-septate ascospores than C. japonica (1-septate, 19–26 × 4.5–5.5 μm).