Vegetatively not to be kept apart from Oncidium cebolleta (3rd photo), this plant with terete leaves originates from hot savannahs or woodlands in the north of South America. It is sensitive to humidity and cold water in winter.
Some people call it now Trichocentrum, but I don't want to follow.
The golden flowers smell of marguerites (oxeye daisy, Leucanthemum), mothball or my grandmothers wardrobe, not bad from a little distance.