Sistotremastrum species

Hou, Li-Xin, Li, Xiang-Lin, Luo, Kai-Yue, Dai, Yu-Cheng, Yuan, Yuan & Zhou, Meng, 2025, A new species of Sistotremastrum (Sistotremastrales, Basidiomycota) from subtropical China, Phytotaxa 690 (1), pp. 89-98 : 96

Key to Sistotremastrum species

We put forth a revised key for the Sistotremastrum species ( Gérald & Alvarado 2021), which includes the insertion of S. massonianum in boldface text as follows:

1. Basidiome smooth to tuberculate ......................................................................................................................................................2.

1. Basidiome odontoid...........................................................................................................................................................................8.

2. Strands present...................................................................................................................................................................................3.

2. Strands absent....................................................................................................................................................................................5.

3. Hyphae in strands 5–6 µm in diam.................................................................................................................................. S. induratum

3. Hyphae in strands 1.5–2.5 µm in diam..............................................................................................................................................4.

4. Hyphidia projecting (especially in young specimens) up to 15 μm above hymenial layer present .................................. S. suecicum

4. Hyphidia embedded in the hymenial layer.......................................................................................................................... S. mendax

5. Hymenophore pale orange to orange when fresh, pale orange to grayish orange to brownish orange on drying and hyphidia absent.................................................................................................................................................................................... S. roseum

5. Hymenophore white to cream-colored or pale ochraceous and hyphidia present.............................................................................6.

6. Basidiospores 4–5 µm long ................................................................................................................................................. S. rigidum

6. Basidiospores more than 5 µm long..................................................................................................................................................7.

7. Basidiomata soft, occurring on angiosperm hosts, tropical species ................................................................................. S. confusum

7. Basidiomata hard, occurring on coniferous hosts, temperate to boreal species .................................................................. S. vigilans

8. Cystidia (leptocystidia) present ......................................................................................................................................... S. geminum

8. Cystidia absent...................................................................................................................................................................................9.

9. Aculei 2–3 per mm or semiporoid present ........................................................................................................................ S. geminum

9. Aculei more than 3 per mm and semiporoid absent ........................................................................................................................10.

10. Aculei 3–5 per mm ................................................................................................................................................... S. massonianum

10. Aculei more than 5 per mm .............................................................................................................................................................11.

11. Basidia 7.2–12.2 µm long............................................................................................................................................ S. denticulatum

11. Basidia 14–19 µm long....................................................................................................................................................................12.

12. Subhymenial hyphae 3−4 μm in diam. and basidiospores 2.5−3.0 µm long ......................................................... S. aculeocrepitans

12. Subhymenial hyphae 1.5–2.5 μm in diam. and basidiospores 2.5 µm long................................................................... S. fibrillosum