I've never heard anyone expound on this subject before.
But, to me what I'm about to say is trivially true from my experience and observations.
Anyone disagree?
I welcome your comments.
When most people see a Dendrobium, it is usually in a pot that has been grown indoors: a greenhouse, or a home, by a grower or enthusiast.
When you purchase an orchid, it is nicely and neatly in a pot.
To conserve growing space they are neatly tied, clamped or whatever into a vertical position.
The more they are kept compact, the more you can get in to the your growing space.
Anything necessary for more orchids.
As a reformed inhome grower, I fully agree with that sentiment.
I've even seen pendant Dendrobiums tied into a vertical growth habit.
Den. pendulum is an example that sticks in my mind.
Orchids are not naturally neat, orderly, space saving growers.
But, they can be trained to be.
That is what the normal orchid enthusiast sees and thinks that's how they are.
While not a very good example yet, this is a group of a Den. nobile hybrid.
They are well into their second year after mounting here.
Some did bloom last spring, but the PBs are not yet as large as they will be in a year or a few.
Instead of mounting them on top of the trunk, I tied them to the side of it to encourage them to grow recumbent.
The planting I was given these from was growing very much like this group growing in a neighbor's yard.
There are several others around the area that are growing similarly.
Almost all of them are Yamamoto hybrids.
The two pictured here are.
Every Yamamoto Dendrobium you normally see for sale in a pot is neatly growing vertically.