Three coralloid species of the genus Trechispora (Trechisporales, Basidiomycota) in China: two newly discovered taxa and one reported for the first time Author Deng, Peng-Tao https://orcid.org/0000-0002-8755-7965 College of Life Science, Hunan Normal University, Changsha 410081, China Author Yan, Jun https://orcid.org/0000-0002-2832-8046 College of Life Science, Hunan Normal University, Changsha 410081, China Author Liu, Xiang-Fen College of Life Science, Hunan Normal University, Changsha 410081, China Author He, Zheng-Mi https://orcid.org/0000-0001-8754-3427 College of Life Science, Hunan Normal University, Changsha 410081, China Author Lin, Yuan Bureau of Forestry, Tongdao Dong Autonomous County, Huaihua, Hunan 418500, China Author Lu, Ming-Xin Bureau of Forestry, Tongdao Dong Autonomous County, Huaihua, Hunan 418500, China Author Zhang, Ping https://orcid.org/0000-0002-8751-704X College of Life Science, Hunan Normal University, Changsha 410081, China zhangping0000@163.net text MycoKeys 2023 2023-09-07 99 153 170 http://dx.doi.org/10.3897/mycokeys.99.109375 journal article http://dx.doi.org/10.3897/mycokeys.99.109375 1314-4049-99-153 5867DAD4BAD85603A7904B48DAFD8B78 Trechispora laxa P. Zhang & P.T. Deng sp. nov. Figs 5 , 6 , 7 Diagnosis. Differs from Trechispora havencampii by the loose branches and 4-spored basidia. Type . China , Hainan Province , Baoting County , Qixianling Hot Springs National Forest Park , 18°70′24″N, 109°69′35″E, 300 m asl , 31 July 2021 , leg. P. Zhang ( holotype MHHNU10714) . Etymology. laxus (Latin), loose, referring to the loose branching. Basidiomata. Solitary or scattered, fleshy consistency, 45-55 mm tall, 30-35 mm broad, fresh color (8B6-7), apices white when young but turning grayish purple (14B6) with age, drying pale grayish beige (4C3). Stipe single, white (1A1), 10-15 mm tall. Branches polychotomous from the stipe, dichotomous towards apices, not flattened, loose, divided 3-5 times, terminal branches relatively short and with color transitions to lilac, apices pale purple or white, acute, axils U-shaped. Taste and odor not recorded. Figure 5. Basidiomata of Trechispora laxa (MHHNU10714). Scale bars: 1 cm. Micromorphology. Context with parallel arranged hyphae, 2-4 μm wide; generative hyphae clamped, smooth, thin-walled, hyaline, no calcium oxalate crystals. Subhymenial hyphae branched and wide, 3-8 μm ; ampullate septa present at the base of the stipe, up to 6-8 μm wide. Basidia 20-26 x 7-9 µm with four sterigmata 4-5 µm long and a basal clamp connection, hyaline, subclavate, barrel-shaped. Cystidia absent. Basidiospores [40/3/2] 5-6 x 3-4 μm [Q = 1.25-1.71(1.83), Qm = 1.46 +/- 0.16], ellipsoid, slightly irregular, inner side slightly concave, aculeate or finely verrucose, spines 1-1.5 μm long, apex not sharp but blunt; hilar appendage obscured by spore ornamentation; usually uniguttulate; hyaline, thin-walled, inamyloid. Figure 6. Microscopic features of Trechispora laxa (MHHNU10714) a basidiospores b basidia. Habit and distribution. Solitary or scattered, grows in soil in broadleaf forest; basidiomata generally occur in summer. Known only from the type locality in China. Figure 7. Scanning electron micrograph of basidiospores of Trechispora laxa (MHHNU10714). Notes. The branches of T. laxa are scattered, not dense, and the apices are white or lilac gray with age. In the field, T. laxa and Trechispora havencampii are similar because of their pale grayish brown coloration, but T. havencampii has dense branches, tips white and axils V-shaped, and 2-spored basidia with long sterigmata (5-9.5µm). Trechispora longiramosa differs from T. laxa by having long terminal branches, densely branched and white to honey-yellow tips. Trechispora sanpapaoensis has smaller basidia (11-26 x 5.5-11.0 μm ) and a grayish brown stipe. Trechispora termitophila develops abundant basidiomata in active termite nests, but T. laxa generally grows in the soil of broadleaf forest. Trechispora foetida has a reddish brown to deep brown, flattened stipe, and branching in one plane. In comparison, T. laxa is flesh colored, turning grayish purple in the terminal branches, the branches are not flattened, the branches are not white, and the stipe is non-flat. An additional pigmented species, Trechispora robusta described from Brazil, is pale grayish with internodes irregular, branches flattened to subcylindrical, and inflated hyphae.