Cyathodium Lehm.

Key to the species of Cyathodium in China 1. Plants possessing non-hairy involucres ........................................................................................... 2 – Plants possessing hairy involucres ................................................................................................... 4 2. Mature spores permanently united in tetrads ............................................... C. tetrasporum sp. nov. – Mature spores not permanently united in tetrads ............................................................................. 3 3. Spores 40–83 μm in diameter with baculate ornamentations; thalli up to 4 mm wide; elaters 8–11 per capsule ........................................................................................... C. cavernarum Kunze ex Lehm. – Spores 36–52 μm in diameter with small granulose ornamentation; thalli 0.5–2.6 mm wide; elaters 4–8 per capsule ......................................................................................... C. smaragdinum Schiffn. 4. Mature spores singly or in diads; spore surface with baculate-tuberculate ornamentation ................ ........................................................................................................... C. indicum Udar & D.K.Singh – Mature spores occurring singly; spore surface with baculate-muricate ornamentation .................. 5 5. Thallus with ventral pores; spores with spinate ornamentations, spines with rounded apex ............. ....................................................................................................................... C. tuberosum Kashyap – Thallus without ventral pores; spores with tuberculate or spinate ornamentations, spines with pointed apex .................................................................................................................................................. 6 6. Spores with spinate ornamentation, spines 5–7 μm long ...................... C. aureonitens (Griff.) Mitt. – Spores with tuberculate ornamentation, tubercles 2.5–3.0 μm long ................................................... .................................................................................................. C. tuberculatum Udar & D.K.Singh