Saturday, January 26, 2019

My Year of Orchids: How does the orchid plant experience its immediate environment?

I ask this question because it’s a cool morning, just below 50, and while it’s not that humid lots of my plants, for example the banana leaves, had dew on them. I felt inside a couple of the orchid baskets and they were damp. So my inclination at least for this morning is to not water.

But the orchids that aren’t in baskets look a little dry. Their roots are just off white. They are not hanging but kind of crunched up. And they’re more stiff to the touch than flexible. So how are these plants experiencing the air around them? How much is the breeze affecting them? How are they perceiving the temperature? How powerfully do they feel the sun? To what extent are they drying out?

I like to look at the orchid body as a kind of sculpture in space. I’m drawn to abstract shapes and in a way the orchid is like that. More so than say a bromeliad with its organized rosette. But it would be silly to call the orchid random or disorganized. Of course it is made of roots, shoots, and leaves. But the way these features organize themselves on a growing surface might tend to obfuscate their strict organization.

Some of the orchids look folded, or almost folded, tending to turn in on themselves. Or they make small spaces where the “folds” are or between stems of among leaves. So there are small spaces that form, and are present, where the air is calmer, where some moisture collects, where temperatures are maintained, where sunlight is less direct. The orchid body surrounding these spaces must be reacting to its micro-environment just the way outward facing parts of the body interact with the general environment. So it’s possible isn’t it that the same plant may be experiencing different conditions along different parts of its body. This suggests to me that there are slightly different physiological activities at work among groups of anatomically similar cells.

There are also dark spots and areas of “discoloration” that are a response to the environment. Whether these indicate a difference in tissue types or whether they are regions of pigment, for example red-purple antioxidants like anthocyanins, these “discolored” areas are mitigating the severity of the surface, so that the orchid-environment interface is modified. By the way I put discolored in quotes because I like those spots and blemishes. I want my orchids to hang out the way they do in nature, not like well behaved greenhouse pets.

Another mitigating factor is the boundary layer that every plant surface experiences. The boundary layer is a small space just above the surface of the plant that is slightly less windy/cold/hot/dry than the area just above it. So by the fact of having a boundary layer the orchid body is further protected from the ravages of space around it. Wind decreases the protective boundary layer which is why orchids are particularly susceptible to a cold wind.

So how are my orchids experiencing this cool morning? My guess is that their metabolism is a little slower. They are slower to wake up. They may be a little thirsty later in the day but right now a cold shower of mist, especially one with molecules of fertilizer in it, probably isn’t their idea of a perfect morning. I’ll let them build into the day.

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