Friday, July 21, 2023

A Beautiful Bouteloua Bonanza

Bouteloua curtipendula (side oats grama)

Species from the genus Bouteloua (from the subfamily Chloridoideae) are one of the dominant plants of the shortgrass prairie.

These relatively small grasses include Bouteloua gracilis (blue grama grass), Bouteloua dactyloides (buffalo grass), and Bouteloua curtipendula (side oats grama)

The shortgrass prairie is an ecoregion that is semi-arid, with cool winters and warm summers. It occupies a slice of land in North America to the west of the more famous tall grass prairies, with a region of mixed grasses between them. As indicated by the name, the ecoregion is dominated by short-statured grasses such as Bouteloua spp.

Modified from wikipedia By User: TheshibbolethHowpper 

A lot of the attention on prairies in general are focused on the tallgrass species, such as Andropogon gerardii, Schizachyrium scoparium, Panicum virgatum, and the like, but as I travelled through the states with mixed and short grass prairies, I fell into serious liking (even loving!) for the short-statured grasses that are found in these expansive areas.

Both B. gracilis and B. dactyloides are really small grasses, but their reproductive structures are quite distinctive and in my eyes quite beautiful. The inflorescence of B. gracilis (blue grama grass) is small, but easily seen with the naked eye even from the height of a person, since they usually occur in masses. 

B. gracilis

The species is especially attractive when the bright green anthers start poking out from the spikelets, and I have seen this species used quite liberally as ornamentals here in Colorado, and elsewhere, such as western Kansas. I remember my first experience with this species was in New Mexico several years back. At the time, I had never seen such an odd looking inflorescence.

B.gracilis with green anthers and ant on top!

B. dactyloides (buffalo grass) is even more unusual when it comes to reproduction. It is one of the few grasses that are mostly dioecious, with some individuals having only female flowers, and some individuals having only male flowers. In addition, most grasses have perfect flowers, which contain both male and female reproductive parts in the same flower, but B. dactyloides flowers are mostly unisexual, either having male OR female parts. 


The staminate (male) flowerheads are distinctive, with bright orangey anthers. Unlike B.gracilis, it is a bit harder to spot B. dactyloides by its flowerhead from a distance, but I've found that experience seeing the grass many times does help.

B.dactyloides male staminate flowerhead

The female pistillate structures of B. dactyloides are even more unusual. They are hidden beneath the leaves, the 3 to 5 spikelets protected by spikes. Each spikelet has only one floret, and once fertilized the entire spike structure falls to the ground.

B.dactyloides female pistillate flowerhead

The species has been used as turf grass, and I remember wanting to see whether I could use it in my lawn in New Jersey. The main problem with its use as a lawn is that it does tend to brown and go into hibernation as the cold approaches, which would be slightly problematic in a suburban environment used to green lawns all year round.

B. dactyloides staminate spikelet

Finally, perhaps the most beautiful species in the genus that I've seen so far is Bouteloua curtipendula (side oats grama).

This is a somewhat larger species than the two others, and its inflorescence is a long spike. The spikelets have iridescent violet and green hues interspersed with cream, and look like streamlined and aerodynamic hood ornaments on a race car.

Bouteloua curtipendulaa (pre-anthesis)

The appearance of orange anthers later simply adds to the alluring look of this species. I usually see specimens of this species as lone individuals, unlike B. gracilis and B. dactyloides, which are more rhizomatous and spread clusters or colonies. 

Bouteloua curtipendulaa with orange anthers and white stigma

There are other species in the genus here in Colorado, such as Bouteloua hirsuta, which has a rachis that extends well past the spikelets, and I am hoping that I get to see and photograph these as well in the short time that I am here. But in the meantime, I spend time marveling at the various little beauties that I find as I hike the the hidden and not so hidden pathways in the area.

Bouteloua gracilis with green anthers


  1. It's a great year for B. gracilis here in the Laramie Basin with all the moisture. I've never seen so many stems and such densities of heads! Really beautiful :)

    1. It's become one of my fav grasses. I can see why some places here use it as ornamentals.

  2. Beautiful! I am in New Mexico and as part of my project to go native, I would like to use buffalo grass as an alternative. Just a section of the backyard for now. Thanks for showing how interesting it is

    - Carol

    1. Go for it! I think that state is perfect for the species.