[OGD] Re: Orchids Digest, Vol 6, Issue 368
You wrote:
We court unpopularity by continuing. Are you willing to take the risk ?
Given the now-effective killfile operating vis a vis some potential objectors,
of course.
I take the point on D. crumenatum and other mat formers - mine flowered last
w/end with upward of a thousand blossoms. (No doubt you have a tree full, but
this is Britain.) However, the legendary complexity of the orchid flower in
general implies that this complexity does something, or once did something;
and the only thing that it could have done it to was either le bon dieu or its
pollinator. No?
Anyway, to the tetchy concept of swarms. All sciences go through three
phases: naming the parts, building a phenomenology - what works - and finally
an understanding of the clockwork: why the divisions, why the system in
question works. Plant taxonomy was confronted with the riches of the world in
the C18 and C19th, and reacted with names, sets and other completely
understandable and helpful things. However, we are now moving into the third
of the three stages in biology, and these frankly artificial and usually
conceptual divisions will not quite do. Some things need splitting, some need
lumping. Some things are not really things at all, but artifacts of
observation. Practically, anyone who operates in the field knows that the more
you see, the more the neat boundaries tend to blur. Aerides odorata is common
across SE Asia, but a Nepali, Sri Lankan and Sumatran representative of the
local population variance are really very different from each other. If they
were sympatric, no doubt someone would have added two new species - even
genera - to the crowded list of sarcanthineae. Well, of course; for what was
Hooker - or whoever named the (I think Indian) holotype - to know of these
other places at that time. And so forth. But times have changed.
Any population has a variance associated with it. Plot any two characteristics
of a species - petal width, petal length - for several dozen field-measured
representatives and you do not get a point, but a blob. The issue is whether a
related but potentially distinct blob overlaps or is distinct enough to make
it useful to treat its members as distinct. There are three ways into this.
The first, which I find preferable over the others, is for someone who knows
the class of organism well - and these specific populations in particular - to
make a judgement as to whether how they live in the round makes them truly
distinct. Essentially, is it helpful to the expert mind to separate these
entities or no? And by expert, I don't mean someone adept at whisker-counting,
but one possessed of an ecological expertise which asks whether the lives led
by the populations makes them effectively distinct in habit, sexual
transmission and role.
The second is to apply rigor to the phenotypes. This uses principal component
analysis to arrive at a tree structure. Colleagues of mine use this tool on
human populations to see which groups are distinct in their - for example,
political behaviour - with an aim to tailor communications specific to the
subgroups which emerge from this. There is an example where we worked on UN
urban data to arrive at a similar classification of the world's cities on
www.chforum.org/library/xc132.html#dendro This procedure removes - or renders
formal - the human judgement of what matters.
The third procedure uses information from the analysis of the genome and
matters dependent on it. This is pretty primitive at the moment: one or more
genes only, difference measured not for what it says but for how it says it. I
suspect this approach will mature as understanding of the proteome evolves:
that is, what turns off and on in response to which signals in order to
generate a leaf, this kind of leaf, this kind of leaf with hairs...
Ultimately, how you classify something depends on what you want to do with it.
Engines: {IC, turbine, stirling} IC: {sparked, not sparked}; Sparked: {two
stroke, four stroke}; Two stroke: {diddle and dah}. But you could also say
Engines: {durable, high power to weight}; etc or Engines: {pollutive, low
emissions}; and so forth.
There is no universal way of dividing a population into sets, any more than
there is one answer to the question why? (Why is that flower red? Because
Mrs Jones chose it and she like red; because red sells best so horticulturists
breed it and florists stock it; because of anthrocyanin; because humming birds
see red; because that is the colour worn by grooms at weddings ...)
But enough.
_
Oliver Sparrow
Tel: UK (0)20 7736 9716
www.chforum.org
www.treknepal.org
www.datafreeze.com
___
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[OGD] Orquidea (Mex.) 1974
Hi OGD, I'm looking for a copy of an article on Barkeria naevosa by Frederico Halbinger in a 1974 issue of Orquidea (Mex.) 3: 77-83. Please email me off list if you can help. Cheers, Gary Gary Yong Gee Roger Sawkins Phone 61 (0)7 3398 4222 PO Box 57, Cannon Hill Qld 4170 Australia http://www.yonggee.name ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Articles
Does anyone know were I can get any articles on Sophronitis besides the A.O.S May 2004 issue, that someone very kindly sent me. Thanks, Les. [demime 1.01d removed an attachment of type image/gif which had a name of IMSTP.gif] [demime 1.01d removed an attachment of type Image/jpeg which had a name of clear-day2.jpg] ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re: Cleaning pots/thermal sterilization
Sorry to differ with you, and here I think I am on firmer ground than with 8 foot tubes. I used to sterilize all my pots with bleach solution. The past ten years or so I have been sterilizing the clay pots and metal stakes in the self cleaning oven, which I believe gets to 700 deg. F. Way overkill. Laboratory autoclaves, and also the pressure cookers used for flasking, get no where near that temperature. Nor do they need to spend all that much time at temperature. 300F for half an hour is more than adequate (probably also excessive) for all disinfection needs, including virus destruction - after all, they're just nucleic acids surrounded by protein. Should even take care of prions. Just imagine what your roast chicken would be like when cooked at 700F. Carl BSE doesn't affect us ducks Gustafson ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re: Calcium, chloride, and sodium
I found that in a hard water area, the sodium hypochlorite in bleach combined with calcium in the water to saturate the pot with calcium chloride or something similar, which is poisonous to plants. It killed the roots wherever they touched the pot. I may not be exactly right about the chemistry, but I could see the results. Cleaning the pots in the self cleaning oven is harmless and efficient. The oven doesn't care in the least. It's the sodium that matters, calcium is kind of important for cell walls and membranes, for example. Chloride is also important in many processes, for example photosynthesis. Carl It's all on the web, as well as scientific literature Gustafson ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re: Setting up a Terrarium Suitable for Orchids
Hi there: I saw your messageboard posting on the orchid terrarium that you built for your dorm room and wondered if I could ask a question or two, since Im going to attempt the same thing. Im mostly concerned with watering drainage issues, since Id like to be able to set up some kind of timer-controlled watering/misting system for when Im out of town (which happens fairly often). Did you get good results with the reservoir system that you mentioned? And did providing drainage holes in the bottom of the terrarium (plus the fans) eliminate stagnation fungus problems? Im concerned that just sopping up extra water with a sponge would encourage fungus, but I havent tried it myself. You mentioned that you could provide a few digital pictures of the setupwould you be willing to send copies to me? Id be grateful. Thanks very much! Eli Chartkoff Los Angeles ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Re: Orchids Digest, Issue 366, Msg 7--STAINLESS STEEL
There are differing qualities of stainless steel. Lesser qualities will indeed corrode when exposed to chlorine bleach. Anyone who works with surgical tools will verify this, Andy. --Stitzelweller ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] articles...spheroids / Masdevallia / Dracula ?
Les : Always glad to help but could you be more specific ? Are you preparing a book, writing articles on the genera Sophronitis / Masdevallia / Dracula ? What publications do you have in your personal library ? What publications are available at your local orchid society ? What publications are available at the library of your local botanical garden ? *** For the genus Sophronitis, if you want to start from the beginning, you should get the first publication where the name of the genus was mentioned : Botanical Register; consisting of coloured . . . 14: sub t. 1147. 1828. For Dracula : Selbyana 2(2-3): 190-191. 1978. For Masdevallia : Flora Peruvianae, et Chilensis Prodromus 122, pl. 27. 1794. *** I presume that you do not except that someone else will do a thorough research for you on the genera you are interested in. I am sure though that if you already have a good collection of articles that you will get help from subscribers to the OGD for those articles that you cannot get in your neck of the woods. The best of luck in the continuation of your research. Regards, Viateur ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] species concept
How do species concepts deal with the inclusion/exclusion of natural hybrids? In his last post, Greig mentions his concept of species as My taxonomic unit is probably the Biological Species: which can be defined as natural populations of living, reproducing, genetically related individuals isolated from other populations by barriers to gene exchange. How does this concept of species explain natural hybrids? By this definition, as they do not have barriers to gene exchange (at least not total barriers), would the parent species not then be considered the same species? How would this deal with Phalaenopsis x intermedia? As the natural hybrid between P. aphrodite and P. equestris, it has, according to Christenson, also formed a genetically stabilized population which acts like a species and is self-reproducing in nature. I guess here we are seeing the establishment of an individual species in the future, but how to deal with this in terms of Greig's definition of species? Or we could consider P. x leucorrhoda, the natural hybrid of P. aphrodite and P. schilleriana. This has not established itself as a breeding population, only isolated plants. This definition could also ask us to consider Cattleya x guatemalensis, the hybrid of C. skinneri and C. aurantiaca, as all one species. I think I would have to take the definition of species beyond this Biological Species and more to the direction of Greig's interpretation of Peter's: Morphological Species: defined as the smallest population structurally distinct and distinguishable from all others. But then I find that this can create too much splitting off of species for the smallest variations which could be found. Thanks for the discussion. Jay Norris Ravenvision Photographic www.ravenvision.ca ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Fantastic Dendobium crumenatum
We've been talking about Dendrobium crumenatum's habit of flowering prolifically. The following link takes you to some (unfortunately low-res) photos of a particularly good specimen: http://www.orchidspng.com/discus/messages/6/6005.html?1094130901 We couldn't count the flowers ... there were tens of thousands. I'd like to boast that it is mine, but it isn't. Peter O'Byrne Singapore ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] More plant virus stuff
[EMAIL PROTECTED] spaketh thusly: The active ingredient in bleach is not gaseous chlorine but hypochlorite ion, which is not volatile. If hypochlorite in the form of bleach is not volatile, there would be no reason to cap the bottle, and one would not smell chlorine from an open container. Hypochlorite reverts to diatomic chlorine when permitted, reducing the potency of bleach solutions. Bleach is created through a process in which the chlorine is retained in solution by its very high pH; Clorox used to have a very nice web page on the subject, but it seems to have disappeared. In any event, lye (sodium hydroxide) is dissolved in water to produce a solution with a very high pH. The high pH allows chlorine gas which is bubbled up through it to be retained. The chlorine is held in the form of the hypochlorite ion, which is surprisingly ineffective at disinfection. More important is hypochlorous acid, which has ~80x the strength of the hypochlorite ion to deactivate biologicals. Forming hypochlorous acid: Cl2 + H2O --HOCl + HCl (low pH) Forming bleach solution: Cl2 + H2O + 2Na+ + OH- -- 2Na+ + 2OCl- (high pH, equation not balanced) But- if one were to drop the pH of the second solution (with the hypochlorite ion, the OCl-), it goes a little something like this: Equilibrium between hypochlorite and hypochlorous acid: OCl- + H+ -- HOCl (hypochlorous acid) While the hypochlorous acid one is marked as reversible, they're all pretty much reversible, except when gas is released. Plus, it's early in the morning, and I'm caffeine-deprived. Someone will check me on these equations, I trust. However, this last one is very dangerous: too much acid, and the gas chlorine comes out a lot faster than it does when in alkaline solution (bleach). Chlorine is very toxic, of course, in elemental form to us air-breathers. Accordingly, bleach needs no confinement to work properly. It destroys the amino acid tyrosine, a constitute of all complex proteins, on immediate contact; the rest of the organic matter follows close behind. Perhaps it seems too easy to accept without performing traditional orchid rituals, but bleach is really that effective and can be used with confidence to clean pots and sterilize cutting edges. While this may be true under certain conditions, field tests have demonstrated that bleach does not serve to deactivate plant viruses all the time. If memory serves, one of the oldest tests was at Epcot, where tomato plants were tested with bleach-treated cutting edges, and infectivity remained at the 20-30% level with relatively brief exposure (a few minutes). The problem is that cutting edges are not perfectly smooth, and a thin layer of plant sap may protect viruses from deactivation. Scrubbing in conjunction with soaking is required for the best results. It is not at all clear that chlorine is the effective component in bleach for disinfection of tools in any event; trisodium phosphate works as well or better, even with no chlorine in it. The reason is fairly simple: the very high pH of a saturated TSP solution is sufficient to denature viruses. In a similar manner, the very high pH of the bleach solution- from the lye used to hold the chlorine there in the first place- is probably responsible for most of the activity. Virkon S, a chlorine-based disinfectant that does *not* have a high pH, failed to deactivate pepper mild mottle virus (PMMV) in fresh and dried leaf and root material at exposure times of less than 24 hours; even at 24 hours, some material retained infectivity. Similarly, blades treated with Virkon S retained infectivity at a low level at 1, 5, and (in one case) 10 minutes of exposure. These experiments were run with large sample sizes (in the hundreds and even thousands of samples). I cannot supply a time table of the rapidity of destruction of every chemical entity, but it does not take much to destroy functional protoplasm. Twenty-four seconds should suffice, 24 hours gives one a safety margin. I would sooner be suspect of the oven than an exposure to good strong bleach.Bert Pressman The Plant Viruses Online index lists several viruses that have been recorded in refereed literature as infecting orchids. Some data are supplied as follows. Turnip mosaic potyvirus (known from Calanthe): thermal inactivation point (TIP) of 62 degrees C. http://image.fs.uidaho.edu/vide/descr855.htm Cymbidium mosaic potexvirus (from Cattleya): TIP of 60 to 70 degrees C. http://image.fs.uidaho.edu/vide/descr274.htm Orchid fleck(?) rhabdovirus (from Cymbidium and many more): longevity of the sap in vitro (LIV) of 1 days (at 6 degrees C). http://image.fs.uidaho.edu/vide/descr541.htm Cymbidium ringspot tombusvirus (Cymbidium and others): TIP of 85 to 90 degrees C. http://image.fs.uidaho.edu/vide/descr275.htm Odontoglossum ringspot tobamovirus (many genera): TIP of 90 degrees C. This was once known as tobacco mosaic virus
[OGD] Hanging metal screens
I plan to put metal screening immediately in front on the sloping windows of my Green House. (The Green House itself was designed poorly and I was too inexperienced to know any better.) The frame is aluminum. Any suggestions on how to do this? What to use? I was planning on just hanging the wire without a wooden frame. Help!! Thank You in advance, Gail Sklar ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
[OGD] Still more Chlorine
AJ Hicks questions [OGD V6#370] the chemistry behind my recommendation of bleach as a virtually instantaneous sterilization agent. He cites the odor of chlorine in bleach as evidence of the volatility of hypochlorite. He is correct that the manufacture of bleach involves the uptake of gaseous chlorine by a very alkaline solution of lye but he got the chemistry wrong. Hypochlorite is generated by the following equation: Cl2 + 2OH- --- ClO- + Cl- + H2O Although the equilibrium lies strongly to the right, there is always some free chlorine present, which accounts for its odor in bleach; if a small portion of the chlorine escapes as gas, the equilibrium compensates for this by shifting slightly to the left and supplying replacement elemental chlorine. Thus there is always an odor of chlorine coming from bleach without an appreciable portion of it escaping into the atmosphere. Therefore, as I originally stated, no confinement is necessary for bleach to be effective. Even my wife knows this when she does the laundry. The formation of hypochlorous acid at low pH is of no consequence since the pH of bleach is high, therefor the statement, But if one were to drop the pH of the second solution... is irrelevant. The sodium ion, Na+ has nothing to do with it! Yes, acidification could release a lot of chlorine gas, but this, too, is irrelevant since we do not normally add acid to bleach, nor can I figure out why we would ever want to do such a foolish and dangerous thing. I know how fast bleach reacts with cellular material, but the details of contradicting field tests are not given. Perhaps the bleach was too dilute, or perhaps the experimentor did not understand the need to conduct tests with reasonably fresh bleach, or perhaps his tests for live virus were contaminated by external sources of virus. If the experimentor did not understand the underlying principles of destruction of virus by bleach perhaps his technic was flawed. AJ repeats one of the most ridiculous myths of orchidology, namely that there is something mystical about TSP. I am surprised he didn't complete the myth by mentioning that undissolved crystals must be at the bottom of the container, otherwise the magic doesn't work. The antiviral activity of TSP arises from its extremely high pH. You can get the same results by adding 1 teaspoon of lye to a gallon of water. The statement by AJ that TSP is a more effective sterilizing agent than bleach is not even close to true. If the phosphate in TSP contributed to its sterilizing ability, why would we expose our precious orchids to phosphate in our fertilizers? Phosphate, like calcium, is not an enemy of orchid growth but a friend. Virkon S is cited as a chlorine based disinfectant, but it is NOT chlorine or hypochlorite, which we are discussing. Table salt is also chlorine based, but has minimal toxicity unless we are prone to hypertension. A compendium of orchid viruses is included by AJ without explanation of what relevance it has for the effectiveness of bleach in destroying virus. I apologize for being so harsh in responding to AJ's criticisms, but I habitually crusade against myths of orchid culture that are repeated from one orchid grower to another with strong conviction, but are nevertheless without firm scientific support. Growing orchids properly is challenging enough without paying blind respect to these extraneous myths. ___ the OrchidGuide Digest (OGD) [EMAIL PROTECTED] http://lists.orchidguide.com/mailman/listinfo/orchids
