Terete Oncidium in Veracruz state?

[estación seca]

In 2001 I was in Veracruz, México, on the Atlantic slope in seasonally dry oak forest. It is a spot where Dioon edule
ecotype Río Verde grows. In the crown of an oak, in what would be always-dense shade, I saw a terete-leaved plant I think was an Oncidium. It was too dark under the canopy for me to get a photo because the plant was out of flash range and we didn't have a ladder. The leaves were dark green, singly grooved, 12-18 inches long, spindle-shaped, and came to a sharp point. There were about 10 leaves hanging down from the base in a tight cluster. I could not see well enough to see pseudobulbs. I saw no old inflorescences.

Any idea which species this could be? It did not look like O. cebolleta, which is a much smaller plant. Thanks.