Dendrobium bullenianum has long been known as Den. topaziacum and you can still find it in collections, and for sale, labeled as such. Flowers are variable and can range in color from lemon yellow to dusty orange. The best clones have open flowewrs with nicely proportioned petals and sepals and are a clear orange color with red striping. Dendrobium bullenianum is endemic to the Philippines where it is found growing in steamy coastal forests below 300m elevation. Flowers are produced on second-year leafless canes several times a year with the primary flowering occurring in the spring.