Colombia is without a doubt one of the most biodiverse countries in the world, and members of the Orchidaceae family are among the largest contributors. With reports ranging from 3600 to +4200, the country is only surpassed by Ecuador in absolute numbers of orchid species. In relative numbers, estimated as species per area, Colombia is far behind countries like Costa Rica and Panama. However, its size, the complexity of its mountainous systems, and geographical position, flanked by the Atlantic and Pacific Oceans, and with Andean, Central American and Amazonian influences, suggest that it must be much more diverse than any of the surrounding countries. It is this gap between the expected diversity in the country and what is known that we wish to address here.

The necessity for a serial publication illustrating the diversity of Colombian orchids, perhaps the richest orchid flora in the world, emerged from an informal meeting during the VIII Congreso Nacional de Botánica in Manizales, Colombia in 2015. A large part of the current editorial team of Icones Colombianae was present during that meeting. After the successful publication of the first three volumes of the series in 2017, 2018 and 2019, attention towards the orchid flora of Colombia has grown.

The volumes, published as part of the broader Species Orchidacearum serial, have proven to be a useful tool not only for students and researchers, but also for more general audiences, including local communities and decision makers. Careful taxonomic work, enriched by detailed photographic documentation on the local orchid floras, slowly but surely set the basis for a multitude of biodiversity related studies and may be crucial to tackle large and highly diverse countries such as Colombia.

Icones Colombianae aims to promote broad and unrestricted public access to the scientific knowledge on biodiversity. Through this initiative, the work of different local researchers and orchid enthusiasts is made freely available and easily accessible online to the whole community. The interest that people from the communities where the orchids grow have shown in these publications speaks of the important role that such initiatives play in biodiversity education and conservation efforts.

An additional twelve Colombian orchid species are fully illustrated in the form of Lankester Composite Dissection Plates (LCDPs) in the current volume. Two new species are described for the first time: Andinia auriculipetala S.Vieira-Uribe & N.Gutiérrez, a species from La Belleza Municipality in Santander, distinguished by the ear-like petals, and Epidendrum scrotiforme Est.Domínguez, S.Mesa, E.Santiago & Hágsater, a species from Antioquia, that can be recognized by the prominent nectary forming a vesicle.

The publication of the first photographs of these previously undescribed species, as well as of other rare orchids in Icones Colombianae highlight the relevance of these efforts. The reduction of the habitats where these species grow is a constant reminder of the pressures they are under; properly documenting them and making this information easily accesible to anyone interested, is of help in stressing the importance of conservation efforts in these and other areas.

The necessity for a serial publication illustrating the diversity of Colombian orchids, perhaps the richest orchid flora in the world, emerged from an informal meeting during the VIII Congreso Nacional de Botánica in Manizales, Colombia in 2015. A large part of the current editorial team of Icones Colombianae was present during that meeting. After the successful publication of the first three volumes of the series in 2017, 2018 and 2019, attention towards the orchid flora of Colombia has grown.

The volumes, published as part of the broader Species Orchidacearum serial, have proven to be a useful tool not only for students and researchers, but also for more general audiences, including local communities and decision makers. Careful taxonomic work, enriched by detailed photographic documentation on the local orchid floras, slowly but surely set the basis for a multitude of biodiversity related studies and may be crucial to tackle large and highly diverse countries such as Colombia.

Icones Colombianae aims to promote broad and unrestricted public access to the scientific knowledge on biodiversity. Through this initiative, the work of different local researchers and orchid enthusiasts is made freely available and easily accessible online to the whole community. The interest that people from the communities where the orchids grow have shown in these publications speaks of the important role that such initiatives play in biodiversity education and conservation efforts.

In this volume we present for the first time in this serial publication, twelve Colombian species belonging to twelve orchid genera: Acineta, Bifrenaria, Cyrtochilum, Encyclia, Epidendrum, Houlletia, Masdevallia, Odontoglossum, Oncidium, Phragmipedium, Sauvetrea and Xylobium.

Several of the species documented here are very popular among enthusiasts, like Acineta superba, Encyclia stellata, Masdevallia stenorhynchos, Odontoglossum lindleyanum, Oncidium fuscatum, and Xylobium elongatum, while others are very rare in the wild and collections such as Bifrenaria longicornis and Sauvetrea sessilis, here reported for the departments of Vaupes and Santander, respectively. The latter is a poorly known species, here recorded for Colombia for the first time, which belongs to an obscure and poorly illustrated genus. Moreover, Bifrenaria longicornis represents the first Amazonic species documented in this serial publication.

We document three species endemic to Colombia: Epidendrum pazii, Masdevallia stenorhynchos and Phragmipedium schlimii, the two latter were categorized following IUCN criteria as Endangered (EN) due to the loss of their natural habitat and illegal extraction.

The editors