H4 Oat Medium

Originally cited by Clements et al., 1986 (A preliminary report on the symbiotic germination of European terrestrial orchids. Kew  Bulletin, 41, 437-45), modified by Rasmussen et al, 1990 (Temperature sensitivity of in vitro germination and seedling development of  Dactylorhiza majalis (Orchidaceae) with and without a mycorrhizal fungus. Plant, Cell and Environment, 13, 171-7.)

For symbiotic cultures. 

NH4NO3 * 4 H2O  72 mg  KCl  100 mg  KH2PO4  200 mg  MgSO4 * 7 H2O  100 mg  Yeast extract (Difco)  100 mg  Glucose  2 g  Finely ground oats  3 g  Agar  12 g

Source: Rasmussen, H. Terrestrial orchids from seed to mycotrophic plant. Cambridge University Press, Cambridge. 1995.