Ted,

Tolumnias, formerly known as equitant oncidiums, typically have no
pseudobulbs (or if they do, they are quite diminutive), and have "fans" of
fleshy leaves that closely overlap (the definition of "equitant") at the
base. They are somewhat fleshy and typically triangular in cross-section,
with the sides a bit concave, and it seems to be the degree of concavity
that varies with water storage.

As to the herbs in S/H, they do great! I have tried sowing seeds right in
the medium with mixed success, so instead, I sow them in ProMix and
transplant them once they are up and growing. I have also had success
sowing the seeds between layers of moist paper towels and transplant them
once they're germinated and have roots.
--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Artwork, Books and Lots of Free Info!


"Ted Byers" wrote in message
...

"Ray" wrote in message
...
Ted,

Even though they were once lumped into a single genus, tolumnia and
oncidiums are quite different in their natural cultural conditions.

Out of curiosity, how similar are they morphologically? I did a search
for pictures of Tolumnia using google, but the links I have pursued so far
have only shown images of the flowers, which look much like the flowers of
the Oncidiums I have seen.

If I recall correctly (I may be overgeneralizing, but you'll get the
point anyway), tolumnias typically populate spindly branches of shrubs on
the windward side of Caribbean islands and nearby mainland locales. As
such, they are bathed in constant breezes and dry out almost instantly
after rains. Many oncidiums, on the other hand, and more typically
"jungle-based," with the overall wetter conditions seen there.

Do they have the adaptations one would usually expect in plants living in
a relatively arid environment, such as fleshy leaves, perhaps
proportionately larger pseudobulbs than the Oncidiums, roots that are
better designed against dessication than one would expect from a
rainforest epiphyte?

I have never actually seen a Tolumnia in the flesh.

Every attempt I have made to grow tolumnias in true S/H conditions has
failed, which I rationalize by thinking about the vast dissimilarity of
that root climate to that of the twigs. On the other hand, every
pseudobulbed oncidium I've tried - Sharry Baby, a couple of species, and
any big yellow "dancing doll" included - has thrived.

Given what you have said about their natural environment, I would be
astonished if they were found by someone to thrive in semihydro. If there
are people who succeed in growing them in semihydro, what is the reason?
Are they doing it in an environment that has much drier air, and thus much
greater evaporative demand? If so, I could see that demand drying the air
in the pores within the media, while the water in the pellets supplies
sufficient water for the plant to meet that demand. If that is right, I
could see the plant growing faster than normal since plant production is
often correlated with evapotranspiration rates (at least in crop plants
I've studied - I don't know how well that empirical relationship applies
to orchids, if at all).

My statement that I have the ascocentrums in clay pots of PrimeAgra was
meant to point out that PrimeAgra can be used as a non-S/H growing
medium. I did not say they were in S/H. But let me throw some more
confusion into the fray: I would not recommend ascofinetia be grown in
S/H, even though some folks are good at it, but I am successfully growing
Neofinetia falcata that way.

OK, I misunderstood you there.

If Neofinetia does well in semihydro, but Ascofinetia does not, should
that be taken to mean that Ascocentrum does not particularly like
semihydro, and has passed that trait on to Ascofinetia? If not, what is
the reason you wouldn't recommend semihydro for Acsofinetia even though
some succeed with it?

And here is a question about semihydro that is completely unrelated to
orchids, unless there are orchids used as herbs in some cuisine with which
I am completely unfamiliar. My neice is training to be a chef, and I thus
tried to get her started in growing her own herbs, but to no avail. She
must have thumbs even blacker than her mother and aunts, who can even kill
plastic plants. ;-) The question is, if we have some seeds for a
number of herbs, how can we get them germiinated and then growing in
semihydro. My hope is that if we can get them growing in semihydro, she
will be able to maintain them by simply restoring the initial water level
in the reservoir when that drops by a centimetre or two. She is one that
often forgets to water her plants, and so they usually die from
dessication! Of course, seedlings are much more vulnerable to her than a
relatively mature plant, but even they die from dessication eventually.
I'd like to try to make taking care of plants as easy as possible, to
improve her chances of keeping the herbs healthy enough to use in her
outstanding cooking. It is amazing to me that such an outstanding chef
could be so severely challenged when it comes to keeping plants healthy!

Cheers,

Ted

--
R.E. (Ted) Byers, Ph.D., Ed.D.
R & D Decision Support Solutions
http://www.randddecisionsupportsolutions.com/
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