Evergreen grass rosettes

Hairy Panic Grass, Dichanthelium acuminatum

While out walking Raven this afternoon, I noticed a few clumps of grass in our rearmost field where the tall stems had collapsed sideways to reveal a small, dense basal rosette of leaves – still green. They looked much more like early spring shoots than late fall die-back, which I found curious. Were they simply holding on to life for as long as the lack of snow would permit them to? Or would they really remain green all winter long?

There were two means to answer the question: the easy, but longer, way would be to stuff a stick in the ground at one of them and return mid-winter to check. The harder way would be to come home and try to identify the species of grass to find out what its overwintering habits are.

Identifying grass is a little like identifying sparrows or warblers – once you know what to look for and what the differences are, everything can be figured out relatively easily, but when you first start learning it’s all a giant hodge-podge of lookalikes. Right now I just look at a grass and say: grass. And leave it at that.

I started with a handy website called Ontario Grasses, which has helped me before, but I didn’t see anything there that looked like my species. Not all of Ontario’s grass species are yet up on the website (it’s a hobby project done by the guy in his spare time, I gather), so thinking it probably hadn’t been posted yet, I then turned to my checklist of the plants of Lanark County and started Googling each species with a “common” distribution.

When I got to Dichanthelium acuminatum, this Flickr photo turned up in the results, and I leapt out of my chair and danced about the room crying, “That’s it! That’s it!”

Hairy Panic Grass, Dichanthelium acuminatum

Okay, so no dancing was involved, but I did have that Aha! moment at seeing the image. I’m still not 100% that it’s Dichanthelium acuminatum, but I am positive that it’s at least a Dichanthelium sp. And D. acuminatum is a pretty good bet.

Dichanthelium acuminatum is more commonly known as Hairy Panic Grass, or sometimes Tapered Rosette Grass or Woolly Panic Grass. It’s a common and widespread native species, found pretty much throughout southern Canada and the US. After noticing it at the back field, I watched for it on my return walk, but didn’t see it anywhere else. Our three fields have different, distinct grass communities, I think perhaps partly due to differing grazing pressure from the sheep the previous owners kept, though possibly also the result of underlying soil substrate. It’s been interesting to note how species are distributed between the three areas. The part of the field where I found it is, I think, has slightly richer soil and better moisture than the more open, drier fields.

It might have been easier to identify in the fall, when it still had its seedheads, but the little tufts of leaves along the stem are a helpful identifier. There are a number of different panic grass species, but the clumpiness of the stem tufts seems fairly unique. Also, the leaves are hairy, so logically it should be Hairy Panic Grass. Though I’ve found that such observations are not necessarily a guarantee of correct connections. What was left of the seedhead did, at least, help to narrow down the possibilities.

Hairy Panic Grass, Dichanthelium acuminatum

But back to the basal rosette, which was what had first caught my interest. Now that I knew what the species was, the next thing to look up was its wintering habit. Sure enough, it turns out that Dichanthelium (and the closely related Panicum, from which panic grasses take their common name) species maintain an evergreen rosette of short leaves – what I observed is actually many separate plants all clustered tightly together, which is, I gather, how they grow. The evergreen leaves would give them a leg up on some of their other meadow competition through the ability to photosynthesize late into the season, and to start again first thing following snow melt in the spring.

A couple of websites noted that because they remain green, they provide a source of forage for certain herbivores during the winter months (primarily when the snow isn’t too deep, I suppose). One source said White-tailed Deer and Wild Turkey were the main foragers, though noting that it’s felt to be a poor forage for the deer.

So, I was pleased with that discovery, and that I found an answer without too much pain. I’ll be keeping a watch on our fields now to see if I can find it anywhere else.