European species of the rare orchid family (Orchidaceae) have smaller flowers but richer inflorescences in comparison to their relatives – orchids of tropics and subtropics. The representatives of orchid family are characterized by many peculiarities. Their seeds can germinate only in the presence of symbiotic fungi, although, each species is tied to its own type of fungi. Also, each species has special requirements for light, heat, humidity and its pollinators. The orchid families grow in all types of habitats of the Sulov Rocks, such as forests, meadows, rocks and wetlands. Orchis are very sensitive to changes in environment conditions. Some light-demanding species are threatened by spreading shadows at overgrown pastures and meadows, e.g. the lesser butterfly-orchid (Platanthera bifolia), greater butterfly-orchid (Platanthera chlorantha), the early-purple orchid (Orchis mascula), military orchid (Orchis militaris), marsh fragrant orchid (Gymnadenia conopsea). Sphecidaes of the genus Gorytes pollinate Ophrys (Ophrys insectifera). Males are attracted by the smell of a flower, which is similar to the smell of pheromones. After that, they notice the flower itself, which has the shape and color of females. Ophrys (Ophrys holubyana) is rare and cannot be found further to the north of the Sulov Rocks. Orchis pallens thrives on the forest edges and forest glades. There are many species of helleborines. The dark-red helleborine (Epipactis atrorubens) is remarkable. The white hellborine (Cephalanthera damasonium) grows in the beech forests and the red hellborine (Cephalanthera rubra) grows in the pine forests.
Sulov is one of the richest localities of the Orchis families in the Central Europe. In fact, 36 species were registered in the area of the Sulov-Hradna. Many habitats have disappeared irretrievably due to drainage, change of farming and building of cottages, consequently, some species are endangered. Indeed, the occurrence of four species have not been confirmed in the last two decades.