Yours is about as dark as I have seen.
Mine started blooming about nine years from flask. That is probably a long time, but I grow indoors so things are slower for me. They are pretty vigorous plants actually.
@JimNJ I am growing out a flask of this cross and have bloomed five so far. They are very good to excellent. My best one had five flowers. This is how most of them have generally looked with varying degrees of horizontal petals and chunky segments.
Also showed one of the OK ones so you can see...
Definitely HCM. Nice one though!
I have grown quite a few vietnamense. They are pretty difficult, although the most recent batch of two I have from Taiwan does pretty well.
I believe a lot of plants with the vietnamense label are either Ho Chi Min or, Ho Chi Min x vietnamense.
So I have three...
Very difficult to grow from seedling. I have killed several.
My mature plant loves constant moisture. I have it in an Orchiata/sponge roc/charcoal.mix with lots of sphagnum moss. Grown in relative shade too. It is a vigorous outlier that blooms every few years or so.
A few years back growers in Taiwan were showing photos of line-bred sanderianums that looked very much not like sanderianum...wide dorsals, dark ovaries, and odd-looking staminodes. They look for all the world like an MK back cross. These plants have of course made their way into the trade as...
Big plants under 65 watt LED, but the mature roths also get a western window (not pictured), so lots of direct sun in the summer, at which point i reduce the hours of LED on that shelf.
Seedlings are under single 48" LED strips, like 30-38 watts.