In July 2021 Jeff214 sent me keikis from his Dendrobium speciosum var. boreale. He shows the plant in this thread:
Dendrobium speciosum spike watch... - Orchid Board - Most Complete Orchid Forum on the web !
I potted two at my house and took one single-bulb keiki to my mother's garden in coastal Orange County, California. I potted the single bulb keikis in large perlite while awaiting roots.
All three did nothing whatsoever. As I visited my mother over the months and years I noticed the keiki shriveling more and more. By May it looked pretty bad, and I know a lot of people would have thrown it away. The plantlet at my house did nothing in my warm sunroom. My other single-bulb keiki was eaten by a rat.
Just before my most recent visit to my mother I noticed the plant in my sunroom is making new growth from the base. When I got to my mother's house I looked at the keiki as I was watering. It was brown, shriveled and looked dead. I pulled it out of the perlite and saw the base is still alive, and pushing two new growths. No roots yet:
The moral, as Roberta always says, is, "don't throw away old Den. canes until they're really dead." I'm going to soak it in Kelpak from First Rays and pot it up into my humid sunroom.
I don't know why these waited almost 2 years to grow. Jeff214 mentioned the ones he took off the parent began growing immediately.