Trigonidium, abbreviated as Trgdm in horticultural trade, was a formerly accepted genus of orchids comprising roughly twenty species found from Mexico to Brazil.
[1] Trigonidium derives from the Greek "trigonon", meaning "triangle", in reference to the triangular shape of the flowers.
Its pseudobulbs are cylindrical or ovoid with overlapping sheathes at their base and one or two leaves at their apex.
[2] The flowers have shiny pads and eyespots that lure male bees to perform pseudocopulation with the blossoms.
[3] Former species include:[4] Plants formerly placed in the genus grow well in pots with standard epiphyte mix, in intermediate conditions with light shade and high humidity.