I purchased this Dendrobium Cuthbertsonii from Gold Country Orchids at their open house in March of 2020. It is planted in sphagnum moss in a one-inch pot. It had a single flower when I purchased it, and has developed a second flower. It has a reputation for holding these flowers for months.
Dendrobium cuthbertsonii is native to New Guinea. Plants are found at high altitudes (>2000m), on mossy trees or rocks near streams. It usually grows well under the same conditions as the cold-loving genus Masdevallia. High humidity, very good water, and air movement are particularly important. I am currently growing this on the east side of the greenhouse, hanging on the wall where it gets some morning sun, but all other light is indirect.