Dendrobium ionopus
 

Another member of the Section Calcarifera, coming from the Philippines, is Dendrobium ionopus. Closely related to a group of similar species NOT found on the Philippines, rather on different islands moving down toward New Guinea, a classic example of speciation in motion.
D. ionopus had densly clustered flowers, only about 2cm across, green-gold with red brushings, waxy, two ridges in the lip middle, flowers from the leafless canes during its rest and, like most of the Calcariferas likes to be constantly moist. I find this species a bit sensitive to low room humidity and will drop flowers prematurely if exposed to dry heat, which can be a problem in the Winter flowering season. It likes intermediate conditions, profits from a cooler Winter and good air circulation. Otherwise an easy candidate for the windowsill.

Very interesting. I love the clusters of buds.