Unidentified Dendrobium from Viet Nam

[Shmuel Carmeli]

I got this Dendrobium sp. from Viet Nam labeled as Den. schrautii but its flower does not agree with it. It is definitely belonging to the Section Formosea (formerly known a Nigrohirsutae) and its vegetation and flowers closely resemble that of Den. longicornu. I found on the Viet Nam Creature Website a picture of a dendrobium which resembles mine, named Den. chapaense. I couldn't find any other reference for this spices. I add three pictures of the plant and flowers. I'll appriciate your help with the identification of this Dendroium spices.

[King_of_orchid_growing:)]

It's Den longicornu.

[Limbo]

There are about 3 species similiar to D. longicornu. I think the one above is
Dendrobium chapaense Aver., Rheedea 16: 3 (2006).
Growing in North Vietnam, near Sa Pa, may be elsewhere to.