As an aging individual, sometimes I see things that aren’t there.
Bearing that in mind, I swear that my mustard plants move over the course of a day. At least the younger ones. They seem to face their flowers into the sunlight. Which would make them, technically, heliotropic.
Like sunflowers.
But with mustard, you get nothing near as showy as sunflowers. Sunflowers stake their whole reputation on that. With mustard, it’s a lot subtler. It leaves me guessing whether they actually moved, or whether I’m just imaging it. You look at the bed in the AM sun, and you say, are those plants doing what I think they’re doing? Or is that just an effect of the angle of the sunlight? Repeat in the P.M.
And, unlike sunflowers, where you have big, individually-identifiable blooms, with mustard, it’s more of a herd phenomenon. The whole stand of mustard seems to be leaning one way or the other, depending on the time of day.
OK, fair enough. I find the perception of diurnal mustard movement to be mildly entertaining. And almost totally ignored on the internet, which is perhaps even more amusing.
But is it real?
First, the heliotropism appears to be somewhere in the mustard gene pool. You can find the extremely rare internet reference stating that some varieties of mustard are heliotropic. Like so:
Source: https://www.picturethisai.com/wiki/Sinapis_arvensis.html. You have to open links to find this particular text.
Next, can I catch them in the act with a couple of simple snapshots from my phone/camera?
Eh, maybe.
In this first shot, I’m using a weedy vine in the background as a landmark. Note that the stem that was bent right (around 1 PM) was fully upright by evening.
This second example is closer to what I actually experience. Around 1 PM, it sure looks like all those stems are leaning toward the sunlight. Note the strong leaners circled. But, but the end of the day, those strong leaners are gone, and things just … seem a lot more vertical.
Honestly, I think I’m going to have to set up a video camera can catch them in the act. That will be tomorrow’s task. And if these move, as I think they do, compressing a day of video into a few seconds should show that clearly.
Stay tuned.
