IOSPE has
Phymatidium Lindl. 1833 SUBFAMILY Epidendroideae, TRIBE Cymbidieae SUBTRIBE Oncidiinae
NCBI has
Cymbidieae
Oncidiinae
Phymatidium
From the
Kew Bulletin:
A Taxonomic Revision of the Genus Phymatidium (Orchidaceae: Oncidiinae)
"The genus
Phymatidium belongs to the
Ornithocephalus group of
Oncidiinae (
Orchidaceae) and was established by Lindley in 1833 based on
P. delicatum and
P. falcifolium."
I found research papers studying its DNA and concurring it is related to
Ornithocephalus, in
Oncidiinae.
Here is a link I just stumbled upon discussing it in habitat:
Orchid News # 19
Hybrid Mode
