What Happened to Dendrochilum? Why Chain Orchids Are Now Coelogyne
If you have bought a chain orchid recently, you may have noticed a familiar plant with an unfamiliar name. Dendrochilum wenzelii is now Coelogyne wenzelii; Dendrochilum cobbianum is Coelogyne cobbiana; Pholidota chinensis is Coelogyne chinensis. Here is what happened, and what it means for growers.
The 2021 change
In July 2021, Mark Chase, Barbara Gravendeel, B.P. Sulistyo, R.K. Wati and André Schuiteman published a paper in the journal Phytotaxa expanding Coelogyne to include fourteen other genera: Bracisepalum, Bulleyia, Chelonistele, Dendrochilum, Dickasonia, Entomophobia, Geesinkorchis, Gynoglottis, Ischnogyne, Nabaluia, Neogyna, Otochilus, Panisea and Pholidota. Kew’s Plants of the World Online now follows that classification.
Why it happened
DNA studies over the previous two decades showed that Coelogyne, as it had been defined, was not a natural group. Several smaller genera, including Dendrochilum and Pholidota, sat inside it on the family tree rather than beside it. A genus is meant to contain all the descendants of a common ancestor, so botanists had two options: split Coelogyne into many smaller genera, or merge the others into it. The authors chose to merge, which kept the familiar name Coelogyne for the largest number of species. André Schuiteman of Kew later explained the reasoning for growers in the Journal of the Orchid Society of Great Britain (2022).
How the names changed
For most species, only the genus changed – but the species name sometimes changed with it, for three reasons.
1. Grammatical gender
Dendrochilum is grammatically neuter; Coelogyne is feminine. Adjective-style species names change their endings to agree: tenellum becomes tenella (Coelogyne tenella), cobbianum becomes cobbiana.
2. Nouns keep their form
Some species names are nouns rather than adjectives and do not change. Dendrochilum saccolabium, named for a resemblance to the genus Saccolabium, becomes Coelogyne saccolabium.
3. Names already taken
Where a Dendrochilum name would duplicate an existing Coelogyne name, the species needed an entirely new one. Dendrochilum stenophyllum could not become Coelogyne stenophylla, so it is now Coelogyne lagarophylla. Other examples include D. stenochilum, now C. angustichila, and D. micholitzianum, now C. wilhelmii.
Old and new names for the plants we grow
- Dendrochilum wenzelii → Coelogyne wenzelii
- Dendrochilum cobbianum → Coelogyne cobbiana
- Dendrochilum tenellum → Coelogyne tenella
- Dendrochilum saccolabium → Coelogyne saccolabium
- Dendrochilum javieriense → Coelogyne javieriana
- Dendrochilum stenophyllum → Coelogyne lagarophylla
- Pholidota chinensis → Coelogyne chinensis
What it means for growers
Nothing about the plants has changed – only the labels. Culture is exactly as it was. You will continue to see ‘Dendrochilum’ on labels, in books and at shows for years, and many growers still use it informally. We list each plant under the name Kew accepts, with the former name alongside, so you can match it to an old label or reference. When updating your own labels, writing both names (for example, ‘Coelogyne wenzelii (syn. Dendrochilum wenzelii)’) avoids confusion. A permanent marking pen on T-type labels gives you room for both. Our guide to labelling orchids properly covers making labels that last.
For culture, see the Coelogyne & Dendrochilum Orchid Care Guide and how to grow Dendrochilum (chain orchids) in Australia. You can also browse our current Coelogyne and chain orchids.