Dehydrated Phal? Help?

[james mickelso]

Air roots and "sub" roots are the same thing.

[rvalkenburg]

Yes and no... They are the same fabric and structure but should be treated differently when potting. Air roots should stay air root when repotting and not placed in any media. Where sub roots should always be maintained within the media.

[james mickelso]

Negatory. They are the same. And can be planted under the surface or above it. The velamen of the so-called air root is just not as open as those under the media surface to decrease water loss and the velamen under the media is more open due to the more moist environment. You can either cover the roots or allow them to be above the surface. They will grow either way just fine. As roots age on a mount they become more open than newer roots and change appearance.

[rvalkenburg]

We agree to disagree :-).
We all have differences in growing and caring for our lovely Orchids. I have spent years researching root growth and velamen cell structure and the Air roots velamen construction is similar to Terrestrial roots but with many differences as well. The epidermis is thicker and has a mush different absorption capability. Also Air roots assist with photosynthesis as where the Terrestrial roots do very little even in a clear pot. I have seen time and time again, if you place an Air root during re-potting in the media, it will die off, the same with exposing a Terrestrial out of the pot.

[james mickelso]

The surface density is different because under the media it is in a more humid environment while exposed to the air or when young it isn't. But the root is exactly the same and it can go from exposed in the air or buried under media and then repotted opposite. I have repotted many many orchids which have grown new roots and which were on the surface, then put them under the media and they soon became identical to those which always grew under the surface. I have also taken orchids out of pots where those roots were always under the media and mounted them. The roots surface stayed spongy and quickly absorbed water and lived to a ripe old age. The appearance or surface density of an exposed root is an adaption by the orchid to lessen moisture loss. If you desiccate an orchid in a pot where it's roots have grown under the media, then take that orchid out of it's pot, the roots will once again have the same appearance of an exposed root. Water a root that is exposed to the air for awhile, or let it age, and it's surface characteristics will become the same, to an extent, as those of a buried root. I have pictures by the bunches of this. I will dig some out if you'ld like. I belabor this point for the new growers here because of the number of times I read where that new grower is confused by the very appearance of the roots we are discussing. They see a difference between the buried root and the air root and assume they are different roots. I explain they are one and the same because they are. There is a difference in the appearance but not in their functionality. The root under the media will absorb water more quickly than a root that is new or growing above the media because of the environment it is in but when that environment changes it will assume the appearance for that environment. Not as a function of a difference in what they are but in where they are or their age. But they are the same thing. A root.