No Idea-Please Help ID!

[ghuylar]

Hello!

I was visiting a friend today and he asked me for help identifying an orchid in his collection which has no tag. This is the first time it has bloomed for him in the 20 years he has had it due to providing constant summer levels of light and not providing a natural winter photo period. Attached are photos of the flowers, spiking habit, and foliage. It is a LARGE plant and the spikes are probably a foot and a half long if I had to guess? If you have any ideas for a winter flowering plant that looks similar please let me know!

[neophyte]

Maybe Dendrobium speciosum?

[ghuylar]

Honestly, I think you're right on the dot. I looked up pictures and its a dead ringer for the plant I saw. Same thick canes and odd leaves. Flowers have the same shape and color. I'll pass it on, thank you!

[Fairorchids]

Originally Posted by neophyte

Maybe Dendrobium speciosum?

Correct.

There are 3 or 4 different varieties of this species, with varying plant statures. Then, many of the plants in cultivation result from sib crosses, sometimes across the variety lines, so plant sizes vary a lot. It is impressive in bloom, but flowers only last 2-3 weeks.

Key cultivation issues:
Water & fertilize well, as soon as it is done blooming. Do not let it dry out.
Sept 15th: Stop fertilizing.
Oct 15th: Reduce watering by 90% (I give it a splash every 3-4 weeks). Once buds are fully formed, you can increase watering. When flowers start to open, go back to full watering and start fertilizing.

It can go outside as soon as last frost date is past. It is fine in full sun, and it can stay outside till first frost is in the forecast.

[Clawhammer]

Originally Posted by Fairorchids

Correct.

There are 3 or 4 different varieties of this species, with varying plant statures. Then, many of the plants in cultivation result from sib crosses, sometimes across the variety lines, so plant sizes vary a lot. It is impressive in bloom, but flowers only last 2-3 weeks.

Key cultivation issues:
Water & fertilize well, as soon as it is done blooming. Do not let it dry out.
Sept 15th: Stop fertilizing.
Oct 15th: Reduce watering by 90% (I give it a splash every 3-4 weeks). Once buds are fully formed, you can increase watering. When flowers start to open, go back to full watering and start fertilizing.

It can go outside as soon as last frost date is past. It is fine in full sun, and it can stay outside till first frost is in the forecast.

Kim, I got a Den speciosum from SVO about 10 months ago and it has not done a single thing except grow some additional roots. No new growth, no flowers. Bulbs look the exact same (no wrinkling). None of my other 300+ plants have just sat around doing nothing. Any idea why?

[Roberta]

Den speciosum is a VERY slow grower. From the seedling stage, 15 years to flower is not unusual. As Kim noted, there are several varieties... the smaller ones tend to develop a bit faster. But this is one you just want to pretty much ignore and let it grow. It's progress is measured in years, not months. But when it does bloom, oh baby! Then, like with a child, you'll wonder where the last decade went.

I don't give mine any special treatment over the course of the year... but I live in a location where they grow very well outdoors, seem to thrive on whatever weather Mother Nature throws at them.So "big" is less of a problem. I do water them in winter, less than in summer just like everything else because things dry out more slowly. I have found that I have to give them a bit of shading in summer - those hard, tough leaves do burn in direct sun.

[Fairorchids]

Roberta,

You are some 550 miles further south than I am in NJ, so light shade requirement makes sense. Here, at 40 deg N placing them in full sun (together with Den. kingianum & speciosum) works just fine. This should go for Seattle too.

[Roberta]

It's also a matter of sun direction and shading from trees, etc.... my yard is east-west with nothing to block sun, in the summer the area where my Den speciosums live gets absolutely blasted in the middle of summer. I even use light shading on my Cyms. Plants with truly verical leaves (like L. anceps and the rupiculous Laelias) seem to be able to take the blast, but Den speciosum (and kingianum) have leaves that are more horizontal, so it just a bit too much surface area. (I have the burned spots to prove it) In winter, when the sun angle is lower and the sun is more southerly at mid-day, the house blocks direct sun most of the time, so my back yard is really shady - even too shady but nothing I can do about it.