Updates on the classification and numbers of marine fungi Author Calabon, Mark S. Author Jones, E. B. Gareth Author Pang, Ka-Lai Author Abdel-Wahab, Mohamed A. Author Jin, Jing Author Devadatha, Bandarupalli Author Sadaba, Resurreccion B. Author Apurillo, Carlo Chris Author Hyde, Kevin D. text Botanica Marina 2023 Warsaw, Poland 2023-07-21 66 4 213 238 http://dx.doi.org/10.1515/bot-2023-0032 journal article 10.1515/bot-2023-0032 1437-4323 11000251 2.5.6 Hypoxylon aurantium and H. mangrovei Dayarathne et al. (2020a) introduced these two species based on morphological observations and nucleotide differences of the ITS and tub2 gene loci. Hypoxylon aurantium is a distinctive Hypoxylon species in possessing a bright orange ascostromatal surface which is somewhat similar to H. fendleri ( Vasilyeva et al. 2007 ) . Hypoxylon aurantium and H. fendleri formed a sister lineage with high statistical support (97 % ML , 0.97 PP) and the base pair difference of ITS and tub2 gene loci accounts 52 out of 604 (84 %) and 163 bp out of 1028 bp (15 %), respectively. Hypoxylon mangrovei strains formed a well-separated (100 % ML , 1.00 PP) lineage in a sister clade to H. lenormandii , with which it shares some morphological features. They differ in the size of stromata (2 – 3.5 × 1.5 – 2.8 × 0.4 – 1 mm vs. 13 – 85 × 6 – 27 × 0.5 – 1 mm ) and base pair difference: ITS , 27 bp out of 470 bp (5.7 %) and tub2 73 out of 594 (12.3 %) and RPB 2 data.