Dendrobium is a huge genus. It has been subdivided into different Sections of plants with similar growth and flowering. Your Dendrobium is probably in section Dendrobium, and when it flowers you can look it up here:
IOSPE PHOTOS
If it grows in the wild near you, it might be possible to figure out which of these it is. The above site tells where all the plants come from, and has photos.
And I would like to repeat - almost all orchids can be bought from nurseries who propagate them. It damages nature to take them from the wild.
Linear Mode
