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Network analysis is an effective tool to describe and quantify the ecological interactions between plants and root‐associated fungi. Mycoheterotrophic plants, such as orchids, critically rely on mycorrhizal fungi for nutrients to survive, so investigating the structure of those intimate interactions brings new insights into the plant community assembly and coexistence. So far, there is little consensus on the structure of those interactions, described either as nested (generalist interactions), modular (highly specific interactions) or of both topologies. Biotic factors (e.g., mycorrhizal specificity) were shown to influence the network structure, while there is less evidence of abiotic factor effects. By using next‐generation sequencing of the orchid mycorrhizal fungal (OMF) community associated to with plant individuals belonging to 17 orchid species, we assessed the structure of four orchid–OMF networks in two European regions under contrasting climatic conditions (Mediterranean vs. Continental). Each network contained four to 12 co‐occurring orchid species, including six species shared among the regions. All four networks were both nested and modular, and fungal communities were different between co‐occurring orchid species, despite multiple sharing of fungi across some orchids. Co‐occurring orchid species growing in Mediterranean climate were associated with more dissimilar fungal communities, consistent with a more modular network structure compared to the Continental ones. OMF diversity was comparable among orchid species since most orchids were associated with multiple rarer fungi and with only a few highly dominant ones in the roots. Our results provide useful highlights into potential factors involved in structuring plant–mycorrhizal fungus interactions in different climatic conditions.

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A new species of Dichaea sect. Dichaea from the Andean forests in Colombia is described and illustrated based on living material. Dichaea andina is compared with the morphologically similar D. lagotis and D. pendula, from which it can be distinguished by a number of vegetative and floral and features. Dichaea andina differs from D. lagotis in the broadly anchoriform lip, the hypochile transversely subrounded and the epichile transversely narrowly elliptic, briefly apiculate. Similarly, it differs from D. pendula in the caespitose habit, the leaves without cross-venation, and the inflorescence straight produced below the foliage, among other features. Ecological information for the new species is also provided.