2021 August 1

When they reconstructed our road, the final step was to seed the dug-up areas beside the road with grass to reduce erosion. The seed mix that they used was mostly low plants, but there were a significant number of these tall stalks with a distinctive seed head, which I photographed on July 21, 2021:


This is domesticated rye. The seed head is similar to what you see on wheat and barley, but the “beard” (those long shoots projecting up from the seed head) are longer on rye than on wheat or barley.


The seed head stands up straight until it is nearly ripe, at which point it turns light brown and bends over to point towards the ground.


Here we can see the individual grains in the seed head, getting ready to fall out and be dispersed.


The individual grains look pretty similar to wheat, and when they are still a bit green they are soft and fairly tasty.


So it is pretty clear what it is, but the question is why was it in the grass mix? Rye is pretty tall and spindly, and doesn’t look like it would be all that effective as erosion control. The Michigan Department of Transportation has standard ground-cover seed mixes that they specify for use along the edges of roads, so I thought I would look them up and see if they specify rye.

I found a few places selling State Approved Roadside Mixes (Geoturf, Debruyn Seed, Standish Milling), and the primary mix appears to be 50% Perennial Ryegrass, 35% Creeping Red Fescue, and 15% Kentucky Bluegrass.

The thing is, “ryegrass” and “rye” are not the same plant. Ryegrasses are plants in the genus Lolium, and tend to form low-growing clumps that mow nicely to make a lawn. The grain rye, which we have here, is Secale cereale and is clearly very different. While it is possible that they were just seeding with a non-standard mix that contained the grain-type rye on purpose, I kind of wonder if someone made a mistake, and bought the wrong kind of seed because they thought that ryegrass and rye were the same thing.

Anyway. Rye is definitely a domesticated grain, with seedheads that hold onto their seeds until someone intentionally whacks on them to knock them loose. This is important if you are raising grain, because the normal tendency of a grass is to scatter its seeds willy-nilly as soon as they are ripe. But if a grass that you want to harvest does this, you will lose most of your grain. And so, domesticated grains like wheat, rye, barley, and corn have been selected to hold onto their seeds so that we can harvest them.

An interesting point about rye is that it maybe wasn’t actually domesticated on purpose. What our ancestors intended to domesticate was wheat, which is a different genus (Triticum). But even though rye is a separate genus and doesn’t easily cross with wheat[1], it looks similar enough that it ended up growing along with the wheat and getting harvested with it. And, through Vavilovian mimicry, as the wheat grains were selected to be large and plump and tasty, the rye grains plumped up too so that they wouldn’t be detected as a weed and left out. There is even a comic strip about this:

“Eat me like beautiful wheat gets eaten!”

[1] It is possible to cross wheat and rye, but you have to really work at it. The grain triticale was bred by using rye pollen to fertilize wheat, and then treating it with colchicine to make the plant have multiple copies of all of its chromosomes so that the resulting hybrid wouldn’t be sterile. The most commercially successful variety of triticale is the hexaploid variety, which I gather means that every chromosome was duplicated six times.

3 Responses
  1. August 2, 2021

    Totally off-topic for this post, but have you seen this: https://www.youtube.com/watch?v=VwiHf2T9bLU


  2. August 3, 2021

    KT: That tiny camera looks like it would be just the thing for sending down inside of anthills.

  3. Lyle L permalink
    August 18, 2021

    The grain that the Tribbles eat in the Star Trek “Trouble with Tribbles” episode (and die from because it’s been poisoned) is a (fictional) quadroTritcale

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