Q I have an orchid identified as Mtdm. Hawaiian Sunset x Milt. warscewiczii. What does Mtdm. stand for?

A The abbreviation Mtdm. stands for Miltonidium, a cross that involves the genera Miltonia and Oncidium. In your case, Mtdm. Hawaiian Sunset is a cross of Miltonidium Pupukea Sunset and Miltonia warscewiczii, registered in 1997 by H&R Nurseries. Miltonia warscewiczii is the horticultural name of Oncidium fuscatum