Oncidium Nanboh Waltz black streaks

[fragrantphals]

I divided a friend's oncidium Nanboh Waltz (Makalii x Ornithorhynchum) and kept the old growth and gave her the piece with lots of new growth. The old growth has black streaks on both sides of the leaves, as if someone took a black pen and made lines on the leaves. The new growth has beautiful unmarked foliage, even the mature new growth on newer pseudobulbs. I think the plant was from a big box store. I hope it isn't a virus, but I don't think it is because the plant was grown in low light conditions for at least 1 year and the lines never showed up on the new growth, even under that stress. Has anyone seen this on Oncidiums before, and what is it? It is apart from my other plants now but I would like to put it under my lights with the rest of them. Thanks!

[dracula]

Hi fragrantphals,
I think you do not have to worry about it..
I think it's purely genetic because of its hybridation with Oncd Ornithorhynchum... it appears on older plants particularly when light is high. Same happens with Ascocentrum (and others) wich is heavily black spotted by high light and much more when display in full sun...

[Tindomul]

Interesting. Dracula, would these be the same reasons for spotting in other Oncidiums? Like Sharry Baby? Thanks.

[justatypn]

I don't think so Tindo, the spotting is from misting form what I was told. They are not so fond of misting. I know my Sharry did not have any spots on them when I brought it home and I mist regularly and wanted to see if it showed any signs of misting spots...yep...they are there. It's not going to do harm, just looks like its a healthy ailing leaf...if they become so overwhelming try connecting the dots and see who wins with the most squares All kidding aside, your Sharry should be fine

[dracula]

.. I copy this on the enet 2 or 3 years ago when I got mine... sorry I don't remember where it was... :
"Oncidium ornithorhynchum is a compact species which throws
short length spikes of pinkish 1" blooms with a delightful scent.
The plant is technically a cool grower, being grown mostly by
hobbyists in intermediate conditions. These conditions cause
pronounced markings on the leaves that are not harmful. This
condition is the reason the plant carries a "5" on our growability
scale. In practice, the plant is easy growing and will bloom readily.

To combat the problems with heat, we grow this species in a fine
fir bark mix, keeping damp, to facilitate cooling via evaporation.
The hobbyist can further help the cause by potting it in a clay pot.
Temps can range from the 50's all the way up to 90. This plant is
also an excellent candidate for water culture, blooming 2-3 times
per year for us."
... so I think it may be the same for most of his hybrids ... for culture conditions.. Phil's Orchid Site - Genus review - ONCIDIUM SECTION ROSTRATA ... Oncd ornyth on the same page... (hope this allowed...)

[Tindomul]

Thanks for the info Cheryl! And here I was misting the plant again .
Drac, great info! Now what do they mean by water culture?

[dracula]

Indeed this one does not like misting at all same as many Zygo's...
sorry Tindo... I didn't see your question... as this Oncd should never completly dry out I suppose they mean hydro or semi-hydro culture...