Out of curiosity

[SOS]

How would you go about flasking Masdevallia caesia, a pendant species? They seem anti-gravitropic. Ive spoken with Tom Perlite about flasking them and he told me he had a huge problem with survival rates. I never took into account they must grow upside down.

Indulge me if you would.

[RosieC]

Interesting one. I'm not in to propagation (yet) but I like to read and learn and this one intreages me as well.

[Royal]

Interesting question. My first guess would be that it shouldn't matter. Lots of things grow kind of funny in flask and only "normalize" after being deflasked (Coryanthes, Gongora, etc).

Assuming that this type of growth habit does pose problems, I see one potential option. Let the flask cool in while on its side so that when righted, the media is on a "wall" of the flask. A steep slant may work as well, but either way would require fairly stiff media. Just theorizing here, I've never grown anything like this in vitro.

[King_of_orchid_growing:)]

This does appear to be a major problem.

Even growing in stiff media and placing the flask at a steep angle would be a problem to achieve, as the media would still slide off.

Perhaps the only solution would be to deflask the seedlings before they become pendant in nature.

But again, this would probably incur heavy losses.

[Royal]

How about this idea...

Use a liquid medium, no agar. Grow the plants on a filter paper bridge. This method wicks the nutrient media through the paper, but suspends the plant material above the liquid level. I've never tried this either, but it is not uncommon. I imagine it would take a little practice folding the paper bridges to get them to stay in place during autoclaving. There is probably a technique published somehwere, but here's the basic idea: fold/cut the paper into a long strip, bend the strip into an upside down "U" shape, wedge the "legs" of the "U" down into the flask, use the bottom of the "U" as a platform for the protocorms. Using tall and narrow flasks would allow for longer pendant growth and may help hold the paper bridge in place.

[catwalker808]

I have 2 different comments regarding this issue. First, I believe that the native habitat of the masdevallia is in the southern hemisphere. Tom, in San Francisco, is in the northern hemisphere ... therefore any normal culture there would inherently be growing the plant upside down.

For you skeptics who scoff at this explanation, here's another. There are many pendant growing plants which are propagated and grow under normal tissue culture conditions ... namely with the bottles right side up, with the medium at the bottom. As plants grow larger after they come out of the bottle, the weight & mass of the plant may cause it to be pendant (as with long leaved Brassavolas). Possibly, negative photo-tropism (aversion to light) might play some role in downward growth. If germination & juvenile growth in a flask depended on a flask being upside down, then pendant plants, in nature, would need to germinate and only grow under the limbs of trees. (Plants such as the Masdevallia probably need the shade/ shelter and the moisture seeping down from a branch above).

While still in a flask, plants have very limited weight & mass. The inward sloping flask wall & the neighboring plants would support upward growth. If you wish to test the effects of negative photo-tropism, place the artificial light source under the flask or below & to the side of the flask base.

However, from our extensive experience with growing all kinds of plants in flask, I don't believe it is necessary to grow a flask, slanted or upside down just because an adult plant happens to grow in a pendant manner.

[s1214215]

I agree. I have a flask of Brassovolva sp and it is upright now, but as an adult it is a hanger.

Brett

[Royal]

Originally Posted by catwalker808

I have 2 different comments regarding this issue. First, I believe that the native habitat of the masdevallia is in the southern hemisphere. Tom, in San Francisco, is in the northern hemisphere ... therefore any normal culture there would inherently be growing the plant upside down.

[SOS]

These probably do begin life right side up but their surface area to mass would not be proportionate after the first couple growths. After the third or fourth growth I would assume they want to fall over.

Phototropism is not considered tropic anymore. Its a nastic movement, and uses a 'nasty' suffix.