Goodbye "Sand Lover" grass :-( and a plea for help

I just wanted to come out to share a lament about the taxon swap of Ammophila arenaria to Calamagrostis arenaria. Because, honestly, I’m super sad about the change and I was thinking maybe some other plant geeks would be able to sympathize without thinking I’m insane.

I’ve been giving talks about the Oregon dunes to adults and kids for 20 years. I love telling kids, “…and do you know what? Ammophila means SAND LOVER and that SAND LOVER GRASS LOVES SAND. In fact, it loves it so much that it is spreading all over the dunes and the sand is disappearing!” And from there we talk about how it is altering the dunes by blocking incoming sand via foredune creation, resulting in deflation plane formation and plant succession.

The impact of yelling out SAND LOVER GRASS works. We have a dunes program in Florence with kids starting in 2nd grade, then again in 4th, then again in 7th. When I ask the fourth graders if they remember why the dunes are disappearing, they always yell out SAND LOVER GRASS (so they clearly remember it from second grade). In 7th, they are too cool to yell it out, but they remember and answer the question correctly.

Somehow I think saying REED GRASS isn’t going to work as well. :frowning:

Anyway, my plea for help: Can someone help me (because I’m not a botanist or a scientist) formulate a simple way to explain the name change when giving upcoming talks to adults? What study was done, what they found and why they changed the name. I read the paper attached to the taxon swap in iNat, but honestly, it was a lot of science for this non-scientist…It sounds like a gene study was done and showed the grass to be of a different genus? Is that correct? I would love a few plain English sentences to help me explain it correctly.

Thank you in advance!


You can tell people that species may hide more genetic affinity than how much morphology could suggest. In this light, it has turned out that the genus Ammophila is much more genetically close to Calamagrostis than previously thought on a morphological basis. So that, botanists have decided that it could be worth including Ammophila (which is an newer name) in Agrostis (which is older).

I was a little bit surprised too since spikelets seem so different to my eyes. Anyway, sometimes it has happened that taxonomic changes have been reverted in the light of new findings.


Just wait 3 more years, maybe they’ll rename it back :)


The paper is here (and a second study supports their conclusions):

The discussion of Ammophilia arenaria is buried in the Discussion section and best found by using the “search” feature for this phrase “The relationship between Ammophila and Calamagrostis has been questionable”.

There are many species within this group of plants, each with different sets of traits. Using DNA sequences, which often are a better reflection of actual relationships than morphology, researchers found the two species of Ammophilia to not be closely related. Their similar traits may be caused by adaptation to similar habitats (sand) rather than shared ancestry. Both species are more closely related to species of Calamagrostis than to one another.

This is sort of like discovering that two orphaned siblings (both having red hair and given the surname Rood–Dutch for red), actually had different sets of biological parents (so aren’t actually siblings) despite their shared hair color. And now we know who their relatives actually are (a large clan with the surname Jones; who all have brown hair). It’s sad that their given surname, despite it fitting their traits so well, doesn’t reflect that they were actually born into the Jones family. But everyone is happy that we learned who their actual relatives are. And now we can start to understand more about them–like how’d they come by that red hair!

From the paper:
" The contracted panicles and large spikelets of the two unrelated species of Ammophila that we now recognize in Calamagrostis may be due to selection related to their habitat. Other examples of selection for contracted panicles and large spikelet in pooid grasses that grow in sand dunes include Poa douglasii Nees and P. macrantha Vasey (Poa sect. Madropoa Soreng) in North America, P. cumingii Trin. (sect. Dioicopoa E. Desv.) in South America, and P. billardierei St. Yves (sect. Austrofestuca (Tzvelev) Soreng & L.J. Gillespie) in Australia. The Eastern Asian steppe sand dune genus Psammochloa Hitchc. (Stipeae) also has a contracted panicle with large spikelets, and looks superficially like Ammophila, but it has very different lodicules (three in number that are flabellate and vascularized), a short cauducous awn from between two lobes, and nerves in glumes and lemma with some cross-veins. This pattern of convergent evolution in morphology related to a unique ecological niche warrants further study."


when i think of Ammophila, i think of a wasp. it loves sand, too, and they exist in Oregon. so you can still tell kids that Ammophila loves sand.


At least the specific name, arenaria, is still there and refers to sand. For common name, I’d call it whatever you prefer. And maybe mention the old genus name even if not currently in use.


To me it sounds like an entire generation of kids knows the species as “Sand Lover Grass”, and so do you. This is how common names form, and because you have been saying it for so long, I see no real issue with continuing to call the species “Sand Lover Grass” despite the genus change. Maybe in 50 years it will become the predominant common name.


I think your first paragraph was intended to end, "including Ammophila(which is a newer name) to Calamagrostis [not Agrostis] (which is older).

Pedantic plant taxonomist here. Sorry.

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It sounds like you are worried that a change in the scientific name necessitates a change in science education, but I don’t think this is the case.

It’s great that you want to understand this process, but I don’t think your average adult is going to need an in depth explanation of taxonomy. If someone is interested, it’s definitely good to have a clear explanation, but this is probably a less important part of the grass to be explaining to people.

I was also thinking this. If Ammophila is such an effective means of education, you can still use it by saying, “An older scientific name is Ammophila,” (more correct but maybe more confusing) or, “One scientific name is Ammophila” (less correct but maybe more understandable). The end result should be the same.


Yes, it might be interesting to point out that both scientific and common names are not set in stone and there is variety and change over time and with new understanding of relationships. But I wouldn’t belabor the point as it’s of lesser importance next to what you are trying to teach them.


A freudian slip. Yes, you are a little bit pedantic ;-)


I share your sadness!
It reminds me of when I learned (I was a teenager then) that Brontosaurus (the ‘thunder lizard’) should be Apatosaurus (the ‘deceptive lizard’), that Eohippus (the ‘dawn horse’) should be Hyracotherium (the ‘hyrax animal’) … these were some of my favourite extinct animals.
It’s always sad when names that sound good, get replaced by less inspiring ones, as a result of our increased knowledge of the phylogenetic relationships… That’s the intricacies of taxonomy.
Calamagrostis is indeed an older name (it dates from 1763) than Ammophila (which dates from 1809). See:


I think that maybe saying something along the lines of: “the scientific name used to be Ammophila arenaria, because Ammophila means sand lover, and this plant loves sand” and then continuing with explaining how they changed the name to mean reed grass. And, like @safron said, maybe using it as a common name, since it really does seem to have an impact on kids (and what naturalist doesn’t enjoy seeing a bunch of enthusiastic little kids learn about nature? And kids can retain a surprising amount of knowledge when given the opportunity)


Right now, biologists are trying hard to make sure that all the organisms that share a scientific name are in the same “clade”. A clade is a group that share one common ancestor. The current idea is that each name should be used for ALL the members of that clade.

The species that have been placed in Ammophila do constitute a clade – they’re all descended from the same common ancestor and Ammophila does include all the descendants of that common ancestor. HOWEVER . . . .

Calamagrostis species are all descendants of one common ancestor. As Calamagrostis has traditionally been defined, though, it has not included ALL descendants of that common ancestor. It’s not a complete clade because Ammophila species are also descendants of the last common ancestor of Calamagrostis. In fact, they’re descendants of an ancestor within Calamagrostis. What to do? Option 1: Add the Ammophila species into Calamagrostis. Option 2: split up Calamagrostis into 3 or more genera arranged so that each genus consists of a common ancestor and ALL of its descendants. The choice of whether to split or lump often depends on whether there are some neat lines separating into groups the species within the parent genus, Calamagrostis in this case. Sometimes it’s just a matter of preference, since either option leads to names that meet the definition of clades.

Many of us, of course, prefer Option 3: Let each name refer to a group of species that look alike, that can easily be recognized as each other’s close relatives. This option has absolutely zero traction at the moment, though. Sigh.


Like when Chrysalidocarpus (the ‘butterfly palm’) became Dypsis. Ew!

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yeah i think it’s just a case of having to mourn the loss for now. The people who control taxonomy have decided these sorts of changes are necessary and important, and there isn’t really a mechanism for anyone else to have any input on it. Taxonomy isn’t a democracy, not even close. Social, cultural, or spiritual effects aren’t taken into account with name changes. Just DNA code.

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Not sure how social, cultural, and/or spiritual effects should have any bearing on what scientific names are applied. Yes, contradictory opinions can be involved (lumper vs. splitter) but they arise from different philosophies of where to drawn the line between species and in higher taxa. That’s really a problem of Linnaean taxonomy and organisms that aren’t easily assigned to discrete categories.


it will matter when it matters.


Thank you for this great response with so much detail. For some reason I did not get any notification that there were replies to my post (so I thought it was just dead in the water); imagine my surprise to come out here and see so many responses with helpful information!! :heart:

Thank you.

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This is helpful information. Thank you!