Dendrobium crumenatum Swartz (1799.)
Despite its unruly vegetative growth, its famous flowering habit makes this orchid highly interesting and desirable. Namely, fully developed buds may stay unopened even for months but on the effect of a sudden, say 10 °C temperature drop all will open simultaneously - exactly eight days later, at sunset, within minutes.
In nature the heavy, relatively cool rains arriving after the hot, dry season trigger this unforgettable sight ...