Rhyncostele x humeanum is a naturally occurring hybrid of Rhynchostele cordata and Rhynchostele rossii. This orchid has been easy to grow, potted in hydroton, in our cool room. Even with repotting in the spring, this plant produced an outstanding flower spike in November-January, as you can see in the images below.
Both parent species inhabit the cool to cold, high elevation mist forests of Mexico and Central America. However, Rhynchostele x humeana has been more tolerant of our increasingly warm summer nights compared to our other high elevation orchid species from New Guinea.
The cool room where Rhynchostele x humeana lives is 50F (10C) at night in winter, and has summer highs in the mid 80s (28C). Historically, our summer nights have been 50-55F (10-12C), but for the past two years, we have more consistently seen 55-60F (12-15C) for our summer low temperatures.