In my opinion Dendrobiums are easy to grow and divide. I only have one variety of den. and it was given to me as a "dead" plant by a patient 4-5 yrs ago. The variety is not known. I have a rather large "mother" plant, with the longest stem being approximately 32" long and the overall width of the den. plant is approximately 26". There are three flower stalks present and two more were cut off after blooming. This plant has been in bloom for almost two months and will likely be in bloom until January. I have a 1 yr division that has a flowering stalk and two 6 mo divisions that have not yet grown stalks. These were taken from the mother plant.
The first and last pics are of the mother plant. Notice in the first pic the darker green and older stems and flower stalks on the left and the light green stems on the right. In the last pic the older growth/flowers are on the right with newer growth on the left.
The middle pics are the flowers. Perhaps someone can come up with a name for the variety. Remember to click on the pics for best view. Ken