Here come the Four Horsemen of the Prairies

Panicum virgatum in Open Space area, in Broomfield, CO

Colorado is short grass territory (or at the least the eastern part of the state is), but as summer here is getting into full swing, I noticed that some of the iconic tallgrass prairie species are starting to show themselves.

The Four Horsemen of the Prairies refers to four species that tend to dominate the prairies farther east. The ensemble cast includes Andropogon gerardii (Big Bluestem), Panicum virgatum (Switchgrass) , Schizachyrium scoparium (Little Bluestem), and Sorghastrum nutans (Indiangrass).

Sorghastrum nutans in Broomfield, CO

I must admit that I was not really looking for them, engrossed as I was by the more western oriented species here, but I was walking along one of the Open Spaces in Broomfield when I spotted what looked to be Panicum virgatum in flower. The largish specimens lined part of the path, and a quick check of the flowerhead confirmed the identity.

I've always been a fan of this species as an ornamental, but seeing it in situ always is a treat, especially when in flower.

Sorghastrum nutans in Broomfield, CO

The second "horseman" I saw was one that for one reason or the other, I have not encountered much. This time, I found a slew of Sorghastrum nutans (Indiangrass) flowering along a sidewalk in Broomfield, CO, as well as in the various trails around Boulder.

Many people consider it a beauty, but personally, the fleshy colored and awned flowerheads of the species has never struck me as particularly attractive. Nevertheless, I was enchanted by the small flowerheads, which had escaped the mower blades by virtue of being shielded underneath some metal handhold along the path.

Schizachyrium scoparium along sidewalk in Broomfield, CO

And then there's Schizachyrium scoparium (Little bluestem), which I have owned as an ornamental and is an attractive plant to me. Unfortunately, the single specimen I have stumbled upon so far was still in the earlier stages of flowering, but I am looking forward to seeing more of this species going forward. 

Ladybug on Bothriochloa ischaemum(?). Where art thou Andropogon gerardii?

I was also on the lookout for the biggest horseman of all - Andropogon gerardii (Big Bluestem), but all the lookalikes I found at first seemed to be of some other species...specifically, Bothriochloa ischaemum, which is called yellow bluestem or King ranch Bluestem (in Texas).

Andropogon gerardii near Enchanted Mesa Trail, Boulder, CO

There are trails in that city called Lower and Upper Bluestem trails, and so I expected to find bluestems in the area, which I did. Unfortunately, most seemed to be yellow bluestem (Bothriochloa ischaemum) at this time.

It did not help that my identification skills aren't the best, but I finally found specimens of this large species during one of my hikes in Boulder. Not, as it turns out in the bluestem trails, but in trails closer to Chautauqua Park. Perhaps later in the season this tallest of the Four Horsemen will make its presence more widely known.

Sporobolus michauxianus (formerly Spartina pectinata) near Lower Bluestem Trail, Boulder, CO

Finally, I also found a really tall and attractive species that I identified as Sporobolus michauxianus (formerly Spartina pectinata). This is commonly called Prairie Cordgrass here, and it has amazing

pinkish anthers! When I first saw it from a distance I thought it was some weird A. gerardii, but I'm happy to have met the acquaintance of another spectacular looking member of the Poaceae during my trip to Colorado.

Sporobolus michauxianus (formerly Spartina pectinata) near Lower Bluestem Trail, Boulder, CO

Ornamental Grass Hunting at the Big Box Stores (and Where Big Box Grasses Go to Die)

Leymus arenarius spikelets (taken using non-macro lens)

I am a big fan of ornamental grasses. 

In my time I have purchased many natives such as various Panicum virgatum cultivars ("Northwind",  "Thundercloud", "Heavy Metal", "Hot Rod"), Andropogon gerardii cultivars ("Black Hawk", "RainDance"), and even a few Schizachyrium scoparium like “Twilight Zone”. I even have potential invasives like Miscanthus sinensis "Morning Light" and Japanese Blood Grass (Imperata cylindrica), both of which I obtained a long time back before I knew they were considered iffy ornamentals.

Most of my purchases have been at specialized Garden Centers or from online, but every time I visit Lowe's or Home Depot, I make it a point to visit their Garden department in search of unusual grasses.

The typical store scatters the grasses across various sections, but Lowe's is a favorite of mine because some Lowe's stores even have an ornamental grass section!

You go, Lowe's!

On one trip to a New Jersey Lowe's I decided to list all the available ornamental grasses in the store. 

Most of the ornamental grasses were crowded into one bench, but there were still a few scattered here and there. The usual purple fountain grasses were available (Cenchrus setaceus/Pennisetum setaceum), as were varieties of Miscanthus sinensis ("Adagio", "Variegata"), and the really cute Festuca glauca (in this case, "Beyond Blue"). There were even pots of Cymbopogon citratus (Lemon grass), which normally is placed separately from other ornamentals. These are typical types for this region, as well as in Florida stores (especially the fountain grasses).

Interestingly enough, I did find a species that I normally don't see in New Jersey stores. A couple of pots had Cortaderia selloana (White Pampas Grass)!

An unusual Cortaderia selloana for sale

This species of course has been considered invasive for some time now, but it would be wrong to say it is not gorgeous when in full flower, and so it has been a favorite of lay gardeners in many places. I was surprised to see it here though, as  it usually grows better farther south.

But the species that really stopped me in my tracks was a row of Leymus arenarius. The grasses were in flower, and the blue green hue of the leaves of this native species made me love it on sight. It's safe to say that I will likely get this sand-loving grass in future if I have space for it in my new home.

Leymus arenarius - beautiful in blue

On the way back to my car, I saw some clearance racks that had been parked to the side of the store. Curious about what I would find, I walked closer and found myself staring at the dying and drying bodies of various potted grass specimens. 

Where box store grasses go to die

Most of the dried up plants had grown long, their limp blades obscuring the name tags. I peered closely and found that many of them were Calamagrostis spp, with a couple of Miscanthus sinensis cultivars thrown in and a lone Muhlenbergia sp. A few still had green blades poking up through the mass of dried gold, and I knew that these could still be saved.

When I asked some store reps about the items, they said those plants were going be thrown away if no one bought them at clearance. It seems too many were in stock, and most had deteriorated due to negligence and poor lighting. 

I left after awhile, feeling a bit sad for the dying grasses. There should be a way to calculate the correct stock, and a way to take better care of these ornamental plants.

Exploring the Layered Series of Grasses in an Island

Image 1. Ammophila breviligulata in center

Assateague Island straddles both Maryland and Virginia. It is a narrow barrier island that I visited and hiked this month, and it contains several ecological areas that made it quite diverse when it came to species diversity. Click here to look at a map of the island.

While I was there it came to me that the distribution of the grass species could be described as a series of layers. The major species were different as one went inward from the beaches to the marshes, and then to the drier meadows, and it was quite interesting to see how the species changed  as one hiked inward from the beach dunes.

Image 2. Panicum amarum

In the first and outer layer (the beaches), the two main grasses were Ammophila breviligulata and Panicum amarum. Both are dune building species, and A. breviligulata especially is crucial in creating the huge dunes that protect beaches. It is the dominant dune grass along the northeast coast, and I was familiar with it from my trips to the beaches in New Jersey. 

The two species are also easy to tell apart, with A. ammophila having very thin leaves, while P. amarum has much wider and bluish green leaves. You can clearly see this in Image 3 below.

Image 3. Ammophila breviligulata (left) and Panicum amarum (right)

Their inflorescences are very different as well, as you can see in Image 4 below. A. breviligulata has a whitish spike like inflorescence, while P. amarum has the typical Panicum type spikelets,

Image 4. Ammophila breviligulata (left) and Panicum amarum (right)

As I continued hiking inland into the marshes I came upon the second layer, which is actually composed of several sublayers (see Image 5 below). The area of the marsh closest to the sea (the low marsh) is inundated daily and has higher salt concentrations, and this area was dominated by Sporobolus alterniflorus (Spartina alterniflora). The so-called "high marsh" is farther away, is not inundated all the time, and is less salty. Here I found Sporobolus pumilus (Spartina patens) and the graminoid Juncus roemerianus, which is in the rush plant family and is NOT a grass. 

Image 5. Marsh

It was fairly easy to tell the two grass species apart. S. pumilus has wavy looking blades that look quite beautiful and distinctive. In the image below (Image 6) the species looks almost like a nice soft fluffy lawn.

Image 6. Sporobolus pumilus (Spartina patens) in foreground (NJ pic)

Sporobolus alterniflorus is more erect in form, and it forms the vast bulk of the vegetation that people associate with marshes as they drive towards the beach. The geometric shapes of their vast stands was quite pleasing to the eye, and I spent some time taking various artistic pics of the scenery.  

Image 7. Geometric stands of S. alterniflorus (S. alterniflora) in the background

I even found flowerheads on some of the nearby specimens. The inflorescences were spike-like, with white anthers dangling out from the flattened spikelets and looking quite grub-like.

Image 8. Inflorescence of S. alterniflorus (S. alterniflora)

Beyond the marsh layer was a forested area, but also pockets of large meadows. This most inner layer is surrounded by the beaches and marshes, and I was astonished to find some species that I would never associate with islands. 

Next to the trail were rows of what I believe were Schizachyrium scoparium (little bluestem), and behind them the beautiful panicles of Panicum virgatum (switchgrass) waved in the breeze. Farther back were dense stands of the invasive Phragmites australis (common reed), which also was present in the high marsh.

Image 9. Meadow layer with a series of grass species

It was an amazing thing to be surrounded by such grasses, when just a few minutes away was marshy waters. But unfortunately, the drier landscape, combined with the disturbance regime due to human activity, has also introduced invasive species to the area. I found dense pockets of Microstegium vimineum (Japanese Stiltgrass) in some of the trails, the silvery lines on the upper surfaces of their leaves the most distinctive sign of their presence.

Image 10. Microstegium vimineum

Nevertheless, I really enjoyed visiting and hiking the short trails in the island, and I loved the structured layering of these major grass species throughout the area.

If you ever visit one of these barrier islands, do keep an eye out for the plants around you. The narrowness of such areas make it possible to go from one ecological region to another with just a short walk.

Winter Beauty: Ornamental Grasses!

Panicum virgatum, Schizachyrium scoparium, Calamagrostis sp, Panicum virgatum 

You can find beauty in the most mundane of surroundings.

Deep Cut Gardens in Middletown, NJ features a gorgeous formal garden, tropical and other interesting plants in greenhouses, and short trails for nature lovers. 

But hidden in plain sight in the main parking lot was something that actually made me gasp.

There between the rows of parking spaces and parked cars stood masses of ornamental grasses, their now-dried stems and leaves rising tall and straight towards the cold November sky. Every single island in the lot was filled with these botanical wonders.

The great thing about it was that these were not the non-native Miscanthus sinensis cultivars that are so beloved nowadays by landscape designers, but mostly native perennial grasses.

The tallest were Panicum virgatum cultivars (switch grass), their erect forms standing like disciplined soldiers ready for battle.

P. virgatum

Between stood reddish-hued Schizachyrium scoparium (little bluestem),  another hold-over from the vast prairies of olden America, plus short groupings of what I took to be an elegant Calamagrostis cultivar.

S. scoparium

And for lovers of Miscanthus sinensis, the park had a huge specimen towering over a small decorative pond just steps away from the entrance.

M. sinensis across the pond from the cattails

I love that there has been this strong shift in the landscaping business towards using ornamental grasses as part of their designs. I mean, with their dynamic forms and dramatic color changes over the course of the seasons, such grasses beat boring shrubbery all the time! ;-)

P. virgatum with dried airy panicles still in place

Meet the strange shimmering spikelets of Schizachyrium scoparium (Little Bluestem)

When an observer looks at the seedheads of Schizachyrium scoparium (Little Bluestem), they may gasp at its beauty, and marvel at the whitish fluff that decorate the reddish main axis of the inflorescence. But little do they know what a complex piece of biological engineering that whitish fluff is when viewed at the macro level. 

As many of the Orang Poa (Grass People) know, the unit of reproduction in grasses is the spikelet. The spikelet contains the florets ("flowers") of the grass, and of course the florets (like any flower) contain the stamens (male) and pistils (female). 

In the case of S. scoparium, the spikelets form a complex little unit with many parts. 

Pairs of spikelets run along the axis of the raceme of the inflorescence. Each pair is composed of 2 spikelets (see image below).

The smaller spikelet in the pair sits on top of a pedicel, and is rudimentary and hairy. The larger and fertile spikelet is sessile, with two structures called glumes completely covering the two florets inside. One of the florets is sterile, while the fertile floret has a long bent awn that extends from its central nerve and extends out of the glumes.  You can see the bent awn of the fertile floret in the image below, but the rest of the floret is hidden inside the enclosing glumes.

The unit of dispersal is composed of the two spikelets, in addition to a short segment of the raceme axis. An abscission layer below the axis segment allows the seed-carrying unit to disarticulate from the raceme, and the hairs on the rudimentary spikelet and the axis segment allow it to be carried by the wind for very short distances (typically less than 2 meters from the mother plant).

As I watched, one of the "seeds" floated onto the ground and I took pics of it before the wind could blow it away (see image above). 

(B) is the bent awn of the fertile floret that is being hidden between the enclosing glumes, and (A) is the rudimentary spikelet which sits on a pedicel. The axis segment that connected the unit to the next spikelet pair is labeled (C), and you can see at the top where it was detached from the raceme.

So the next time you see seedheads of S. scoparium, just remember how such simple looking structures actually are composed of wonderfully intricate parts! 

 

Who says I'm not ornamental? Native Schizachyrium scoparium (Little Bluestem)

A lot of times our native grasses get the short shrift even from gardeners, who tend to want the pricey ornamental grass cultivars sold by stores.

But I found this Schizachyrium scoparium on a roadside filled with Little Bluestem, and look at it now. The late afternoon sun was shining on it, and I noticed it looked quite red from a side angle, so I took a quick pic using a cellphone (the one with the Leica lens though).

What a beautiful gem, and 100% native and wild type!

Little Bluestem's Mountain Loving (Schizachyrium scoparium)

Note: My 55 mm lens is screwy, so you'll pardon me because the pics here were all taken with a cellphone camera, though it does have a Leica lens.

I have an inordinate fondness for Schizachyrium scoparium (Little Bluestem). I think it's a combination of its smaller size, its very distinctive habit, and its really cool reddish coloring when Fall comes along. Plus, the species is a member of the "Four Horsemen" of the Tall Grass Prairies, and you can't get any more native than that.

I also hike a lot, and when I get near the top of moderately tall mountain summits, I sometimes spot colonies of this species rising from the stony outcrops like crimson sentinels. It always gives me a thrill to see them, no matter how many times this happens. It's like seeing an old friend again, one who has endeared itself to your heart.

I encountered Little Bluestem again when I drove (then hiked) up Prospect Mountain, near Lake George in New York State. Colonies of this species were scattered on the summit of the mountain, as well as along the roadway that led up to the summit.

S. scoparium seems to thrive when there is lots of sunlight and bare rocky ground, and both are plentiful up where the air is fresh and the wind is sometimes cold. In this case, about 620 meters above sea level, well below the tree line, but sunny enough to make it very happy.

Up here the grass rose from the surrounding stone, their straight reddish forms quite arresting. One particularly large (and flowery) individual stood next to a boulder, the sinuous curves of part of Lake George glittering behind it.

I still remember seeing this species in June 2019 while hiking the Summit Trail in Jenny Jump Forest in NJ. I did not know the name of the grass then (how things have changed in such a short time!), but I still marveled at the sight of the reddish hued straight grass at the summit of Jenny Jump.

So the next time you hike up one of the mountains in the eastern part of the USA, keep a look out for one of these native beauties!

Native grasses during a hike at the Environmental Education Center at Lord Stirling Park (Great Swamp National Wildlife Refuge)

Inflorescence of Andropogon gerardii

Little did I know when we started our hike at the Environmental Education Center (EEC) at Lord Stirling Park that I would finally encounter and identify one of my more sought after species, one of the members of the legendary "Four Horsemen" of the Tall Grass Prairies. These 4 native grasses (Andropogon gerardii/Big Bluestem, Panicum virgatum/Swirchgrass, Sorghatrum nutans/Indiangrass, and Schizachyrium scoparium/Little Bluestem) dominated vast swathes of America before giving way to the spread of another type of grassland with the introduction of corn. 

I was not expecting much because the EEC is located in the Great Swamp National Wildlife Refuge, a remnant of the Wisconsin Glacier, which retreated around 11,000 years ago to form the New Jersey Wetlands. So I thought I would see lots of marshy areas, wilt under the high humidity, and of course be attacked by lots of mosquitoes.

What I did not expect was a very well maintained, and honestly impressive trail system, but that's what I saw. A significant proportion of the path was on wooden boardwalks, which was impressive, and the trails were wide enough that you didn't have to touch vegetation on either side - always a recipe for picking up ticks. It even had a garden near the EEC building, with labeled plants, though not many of the plants were flowering at the time we went there.

Carpet of Microstegium vimineum

We found a trail map of the area and decided that we would move from trail to trail along the periphery of the place, thus maximizing our hiking time. We first traveled counter clockwise along the yellow trail towards Lenape Meadow, and as usual I saw lots of Microstegium vimineum (Stiltgrass) covering the sides of the path, as well as sometimes extending deeper into canopy. This invasive grass is the bane of forest managers, and I had already grown used to encountering it every time I entered some forested area. You can identify stilt grass by the bamboo-like leaves as well as the silvery stripe that runs along the upper leaf surface.

Close up of leaves of Microstegium vimineum

Fortunately however, we did encounter some other plants along the way, including a quite striking plant with dark red flowers, which I later identified as Lobelia cardinalis.

Lobelia cardinalis

We also saw lots of cattails (Typha species) as we crossed the Boondocks Boardwalk along the north end of Lord Stirling Park. The sight of so many cattails was interesting and unexpected because this plant is being pushed aside by a grass called Phragmites australis in most places.. The reason for its health in the area seems to be because the park managers are actively controlling populations of the invasive grass.

Cattail

But what excited me at first was the sight of clumps of S. scoparium (Little Bluestem) at Lenape Meadow.

A clump of S. scoparium at Lenape Meadow (center of pic)

I've always been fond of this species ever since I saw fields of it in New Hampshire, with the distinctive red flowerheads arrowing stright up into the air. Of course, it's only early August, so the S. scoparium I saw at Lenape Meadow still had not gained their full beauty.

S. scoparium in New Hampshire

However, my delight at the discovery of my old friend Little Bluestem was nothing to the amazement that I experienced when we passed Alexander Meadow at the extreme southwest of the park. There I saw a field of grass that almost made my jaw drop. Rising more than 3 meters into the air were flowerheads that looked like turkey feet waving in the air. I had come upon my first field of A. gerardii (Big Bluestem)!!!!

I believe I have never encountered this species before, ever since I started learning more about grasses last year.  The distinctive turkey feet flowerheads and towering height made them almost instantly recognizable, and we passed through the meadow surrounded by these impressive grasses.

A. gerardii inflorescence, looking like turkey feet

I took a few macroshots of the spikelets, which were tightly appressed and had a few dangling yellow or red anthers, although it was obvious that full anthesis had not yet started for many flowerheads.

I also saw quite a number of P. virgatum (Switchgrass) in the field, their wispy flowerheads forming almost a mist-like cloud above the grasses. This species is the 3rd member of the Four Horsemen of the Tall Grass Prairie present in the park, and I had a feeling the 4th and final member (Sorghastrum nutans) might also be somewhere there, although I did not have time to explore the place further.

P.virgatum flowerheads

In the end, it was a very nice and productive hike, although we did sweat throughout the experience, and were bitten by quite a few mosquitoes. 

Here come the C4s! Warm season grasses start flowering

Spikelets of Schizachyrium scoparium

I noticed that two of the grasses I care for at home have started to flower, and both are warm season grasses.

A warm season grass of course refers to a species which reaches its optimal growing rate when the season temperatures are high, normally during mid-Summer. Cold season grasses on the other hand tend to grow fast and flower earlier in the season.

Interestingly enough, the difference between these two groups lies in the way they photosynthesize.

Warm season grasses have C4 photosynthesis, wherein the first carbon compound produced during the process has 4 carbons, whereas cool season grasses have C3 photosynthesis, in which a 3-carbon compound is the initial product.

C4 grasses are much more productive in photosynthesis during hot and dry conditions. So just when C3 cool season grasses start to slow down because of the heat of summer, C4 grasses start revving up their engines.

Flowering spike of Schizachyrium scoparium

Two warm season grasses I have are Panicum virgatum 'Northwind', which I purchased a couple months back, and a specimen of  Schizachyrium scoparium (Little Bluestem), which is native to this area, and which I had obtained last year.

I've always liked S. scoparium, ever since I saw fields of this species on a trip to New Hampshire, and its inflorescence is quite distinctive and beautiful to my eyes.

Spikelets of Panicum virgatum 'Northwind';

The P. virgatum cultivar has also become a favorite of mine, with its erect and tight form and blue green leaves. Its spikelets are quite tiny, and when I photographed them a few days back, they had yet to mature. But I am already looking forward with anticipation to the full panicles maturing, their branches opening up like some botanical umbrella.

Go, go C4s! ;-)