Thursday, December 30, 2021

Update on the rapid expansion of an invasive grass


Almost a year ago, I documented the rapid expansion of an invasive grass. I used Google Street View to show that a cluster of Imperata cylindrica (cogongrass) was expanding at more than 7 meters per year along the east-west gradient of a public roadway.  At the time, I also noted that one end of the dense stand of cogon grass had reached an optical cable marker. 

I visited the same spot again last week (approximately 9 months later) and discovered that the invasive had expanded even farther out, with the line petering out almost 6 meters west past the marker. This new measurement confirmed that the stand is moving at a relatively even pace of between 0.6 to 0.7 meters per month on one end.

I cannot imagine that such methodical and uniform growth can persist against the variety of other species and obstacles the cogongrass encounters, but I will be sure to visit this cluster again in a year or so to see whether I'm proven wrong.

Friday, December 24, 2021

A Grass among the Sea Wrack

 I was strolling along Coligny Beach in Hilton Head Island, SC when I came upon washed up organic debris that looked like grasses. Up to that point, the most interesting thing I had seen were the empty carapaces of horseshoe crabs.

Much to the annoyance of the wife I took some time examining what I found. 

I've  always been interested in drift seeds and drift fruits, which are carried by ocean currents far from their points of origin and deposited by the tides on beaches, where they may have a chance to root and flourish. If you walk beaches often, you'll notice that a line of organic and other "debris" line the sand during the day, and an entire culture of so-called "beaners" comb these sea "wrack" for seabeans and other hidden treasures. 

I don't believe grasses are common in such sea wracks, although there have been cases of masses of dead and dying Phragmites australis washing up to litter beaches in the northeast. The putative grasses that I found were composed of broken and intact culms, with attached fibrous roots and even rhizomes. I at first thought they were palm fragments, but the culms actually look similar to those of Saccharum officinarum (sugarcane) or some small bamboo.

There are of course various dune grasses at the beach, especially Uniola paniculata, which lined the dunes that fronted the whitish sand. But the many fragments I found at the wrack were not this species, nor one of the other dune grasses that I have found.
I also marveled at the fact they seemed to be trying to sprout in the sandy beach, although I doubt anything would come of it. I can only imagine that some storm inland had washed these pieces into a river, from whence the grass fragments had been carried into the open ocean.

I'd love to figure out the identity of the plant, and determine whether they actually will be able to somehow root in the beach, unlikely as that possibility may be. The notion of live grass fragments being carried long distances along the ocean currents to distant shores, on which they can start up a new and thriving population, is really quite fascinating.

Tuesday, December 21, 2021

Google Maps Reveals the Inability of Some Escaped Ornamental Grasses to Expand Laterally

Escaped Cortaderia selloana near Tanger 2 Outlets in December, 2021
I have touted the use of Google Street View as a way to view the behavior of grasses over time. I did this with the invasives Neyraudia reynaudiana (burmareed) and also Imperata cylindrica (cogongrass). In both of those species, Google Street View showed an expansion of the grass as the years passed. 

When I visited the Tanger Outlets in Hilton Head, South Carolina a few days back, I noticed the presence of "escaped" ornamental Cortaderia selloana (pampasgrass) along the roadsides. This species is heavily used in the southeastern states, and the fact that some may have escaped from cultivation was not entirely a surprise. One stand in particular southeast of the outlet had a dense cluster of the invasive.

When I used Google Street View to look at the same area in the past (coordinates 32.237168,-80.8178924), I did not anticipate seeing this same stand years back, but imagine my surprise when I went all the way back to 2013 and the same exact cluster of C. selloana seems to have been in the same spot!

The same stand of Cortaderia selloana in 2013

This seeming stability in pampas grass is interesting because like many grasses it has rhizomes which can aggressively push its way into new territory. Perhaps in this case the surrounding vegetation or environment is not conducive to its spread, or perhaps the last 7 or so years is not enough time to see major changes. When compared to cogongrass especially, such slow expansion is curious, and it would be interesting to find more instances of other escaped ornamentals and see whether this slow rate of expansion is normal.

Sunday, December 12, 2021

First Report of a Succulent Grass with CAM Photosynthesis

Seed of Spinifex sp. by Avenue - Own work, CC BY-SA 3.0

The Poaceae as a whole are about equally divided between those that use C3 photosynthesis, and those that have the C4 version of photosynthesis, which is more energetically costly, but which allows the plants to be more productive in hot and arid environments.

In C3 plants, which are the vast majority of plants in the world, CO2 is directly fixed into a 3-Carbon compound by the enzyme RuBisCo in the Calvin-Benson cycle. Unfortunately,  RuBisCo can use both O2 and CO2, and when a C3 plant closes its stomata in order to conserve water in hot dry environments, more O2 is used, which leads to a net loss of carbon in the plant. In fact, some calculations show that C3 plants could end up wasting up to 40% of absorbed energy due to photorespiration!

C4 plants solve this problem through a carbon-concentrating mechanism. They have a modified leaf anatomy wherein CO2 is first fixed onto a 4-carbon compound in outer mesophyll cells by an enzyme not affected by O2, before being shunted to inner bundle sheath cells, where it is converted back to CO2 for use by RuBisCo in those cells.

CAM process by YikrazuulDerivative: Ed (Edgar181)

CAM plants are also adapted to hot and dry environments, and they also initially fix CO2 into a 4-carbon compound. In their case, they keep their stomata close during the heat of day, then open them at night. The CO2 that comes in when the stomata are open are fixed into a 4-carbon compound by the same enzyme used by C4 plants, then shunted into a nearby vacuole, where they remain until needed to complete carbon fixation during the daytime. So in the case of CAM plants, they concentrate carbon by separating the process temporally, instead of spatially like C4 plants do. 

The Poaceae recently became one of only 8 families of plants that have members using all 3 different photosynthetic methods, with the single grass species that exhibits CAM metabolism able to use both C4 and CAM.

Spinifex littoreus is a halophyte with thick, stiff leaves that is found on coastal sand dunes in East Asia. It has been reported as a C4 plant, with all the concomitant structural modifications for this pathway, but a relatively new study showed evidence that it may also be undergoing CAM metabolism.

Measurements confirmed that the leaves of this species are succulent, which is usually correlated with CAM plants. In addition, the researchers found diel fluctuations in leaf acidity, with acidity rising during night, another clue that it is using CAM photosynthesis. 

If true, S. littoreus is the first grass ever exhibiting CAM, and it will be joining members of the non-grass genus Portulaca as the only plants that can do C4/CAM cycling.

From Flowers of India by Prashant Awale


Che-Ling Ho, Jyh-Min Chiang, Teng-Chiu Lin, Craig E. Martin (2019). First report of C4/CAM-cycling photosynthetic pathway in a succulent grass, Spinifex littoreus (Brum. f.) Merr., in coastal regions of Taiwan, Flora,Volume 254, Pages 194-202, ISSN 0367-2530,

Tuesday, December 7, 2021

Podcast Spotlight: Common Descent - Grass

I listen to podcasts whenever I walk out for exercise.

My favorite podcast would be In Defense of Plants, but I also listen to paleontology related podcasts, and a few days ago I came upon a series hosted by two researchers that is both entertaining and informative.

This episode of Common Descent was extremely interesting because it featured my fav plants - grasses! The guest speaker, Dr. Aly Baumgarter does a good job of giving an overview of the evolution of grasses and their expansion during the last few million years, a topic which I will be tackling as well in future posts.


Thursday, December 2, 2021

Ancient Old Growth Grasslands may be the Safest and Most Reliable Choice for Carbon Storage in the Fight against Climate Change

Osage Plains Prairie in Missouri, by Pat Whalen. To learn more about the importance of protecting original prairie in Missouri, and how you can get involved, please visit

The ability to sequester and store carbon in a manner that will reliably prevent it from pouring back into the atmosphere is essential in our fight to slow global warming and climate change.

Intact and ancient old growth grasslands are our best weapon in this fight in many parts of the world, due to several factors that allow it to more safely store carbon underground compared to forests and degraded secondary grasslands.

What are some factors in our changing climate that affect the reliability of carbon sequestration and storage?

There are two main factors that are increasingly being affected by climate change, and they are wildfires and drought. 

  • Climate change is increasing the frequency and/or severity of fire weather – which is defined as periods with a high fire risk due to a combination of high temperatures, low humidity, low rainfall and often high winds.

    This trend has been confirmed in many regions of the world, including Amazonia, southern Europe, Scandinavia, the Western USA and Canada, Siberia, and Australia. Paleo records have also confirmed the tendency of wildfires to occur during warmer periods of time  (Jones et al, 2020; Smith et al, 2020).

  • Climate change is increasing droughts and drought severity.

    The percentage of geographic areas affected by drought events has increased by approximately 1.74% per decade from 1950 to 2008, and this trend is projected to strengthen under global climate change with more intense droughts.  This will include significant decreases in terrestrial water storage (TWS) the sum of continental water stored in canopies, snow and ice, rivers, lakes, reservoirs, wetlands, soil, and groundwater, which is a critical component of the global water and energy budget (Gao et al, 2019; Shiru et al, 2020; Pokhrel et al, 2021).

What characteristics allow grasslands to sequester and store carbon more safely and reliably when compared to forests?

The increasing probability of drought and wildfires influences the ability of different ecosystems to reliably sequester and store carbon. Although primary forests are essential to our world and also need to be protected, misguided afforestation efforts that destroy ancient grasslands is on the rise, often with disastrous consequences (e.g. planting trees where they cannot survive, or even worse, creating invasive commercial monoculture plantations).

  • Grasslands store enormous amounts of carbon in soil.

    North American grasslands for example can store as much carbon in soil as tropical forests store as biomass. Since grasslands store most of this carbon biomass safely underground, they are less vulnerable to being released back into the atmosphere due to wildfires. In contrast, most tree biomass is above ground and vulnerable. Because of this, grasslands may be more reliable carbon sinks in a world with increasing probability of wildfires (Dass et al, 2018; Veldman et al, 2019; Qi et al, 2019). 

  • Grasslands are more resilient in the face of droughts compared to forests.

    Tree mortality is increasing rapidly due to heat stress and drought in many regions of the world, whereas shorter plants like grasses and shrubs tend to be more resilient, and this can cause forest collapse back to shrubs and grasslands as droughts increase in many parts of the world. Aboveground net productivity (ANPP) in grasslands is also more resilient than forests during long term droughts (McDowell and Allen, 2015; Lloret and Batllori, 2021; Zhang et al, 2021 ).

Why are ancient Old Growth Grasslands better than secondary degraded grasslands in our fight against climate change?

Ancient old growth grasslands store more carbon, are more resistant to fire and are richer in species than secondary grasslands. Grassland degradation led to average losses of 48 and 39% for Soil Organic Carbon  (SOC) and Soil Total Nitrogen (STN) stocks, respectively (Zaloumis & Bond, 2016; Jingjing et al, 2021)

Why do we need to emphasize the importance of ancient grasslands in our quest to mitigate climate change?

We need to continue to strongly advocate for the preservation of ancient old growth grasslands, not only because of their continued destruction at the hands of land developers, but also because of misguided afforestation efforts around the world. Many of these grasslands originated thousands and even millions of years ago, long before the rise of humanity. We owe it to the future to preserve them and the countless animals and plants that make it their home, and in the process help combat climate change.

Andropogon gerardii says "V for Victory!"

References and Literature Cited

Chang, J., Ciais, P., Gasser, T. et al. Climate warming from managed grasslands cancels the cooling effect of carbon sinks in sparsely grazed and natural grasslands. Nat Commun 12, 118 (2021).

Dass Pawlok, Benjamin Z Houlton, Yingping Wang, David Warlind. Grasslands may be more reliable carbon sinks than forests in California. Environmental Research Letters, 2018; 13 (7): 074027 DOI: 10.1088/1748-9326/aacb39

Gao Jiangbo,Linlin Zhang,Ze Tang,Shaohong Wu (2019). A synthesis of ecosystem aboveground productivity and its process variables under simulated drought stress. Journal of EcologyVolume 107, Issue 6 p. 2519-2531

Jackson, R., Banner, J., Jobbágy, E. et al. Ecosystem carbon loss with woody plant invasion of grasslands. Nature 418, 623–626 (2002).

Jingjing Yang, Xuefeng Wu, Ying Chen, Zhanbo Yang, Jushan Liu, Donghui Wu, Deli Wang, Combined attributes of soil nematode communities as indicators of grassland degradation, Ecological Indicators, 10.1016/j.ecolind.2021.108215, 131, (108215), (2021).

Jones, Matthew W., Adam Smith, Richard Betts, Josep G. Canadell, I. Colin Prentice, and Corinne Le Quéré. Climate Change Increases the Risk of Wildfires (2020). ScienceBrief, January 2020.

Lloret F., Batllori E. (2021) Climate-Induced Global Forest Shifts due to Heatwave-Drought. In: Canadell J.G., Jackson R.B. (eds) Ecosystem Collapse and Climate Change. Ecological Studies (Analysis and Synthesis), vol 241. Springer, Cham.

McDowell N G and Allen C D 2015 Darcy’s law predicts widespread forest mortality under climate warming Nat. Clim. Change 5 669–72

Pokhrel, Y., Felfelani, F., Satoh, Y. et al. Global terrestrial water storage and drought severity under climate change. Nat. Clim. Chang. 11, 226–233 (2021).

Shiru, M.S., Shahid, S., Dewan, A. et al. Projection of meteorological droughts in Nigeria during growing seasons under climate change scenarios. Sci Rep 10, 10107 (2020).

Smith, Adam J. P. , Matthew W. Jones, John T. Abatzoglou, Josep G. Canadell, Richard A. Betts (2020). Climate Change Increases the Risk of Wildfires. ScienceBrief, September 2020 Update.

Yulin Qi, Wei Wei, Cungen Chen, Liding Chen (2019). Plant root-shoot biomass allocation over diverse biomes: A global synthesis, Global Ecology and Conservation, Volume 18, e00606,ISSN 2351-9894,

Veldman, Joseph & Aleman, Julie & Alvarado, Swanni & Anderson, Todd & Archibald, Sally & Bond, William & Boutton, Thomas & Buchmann, Nina & Buisson, Elise & Canadell, Josep & Dechoum, Michele & Díaz-Toribio, Milton & Durigan, Giselda & Ewel, John & Fernandes, G. & Fidelis, Alessandra & Fleischman, Forrest & Good, Stephen & Griffith, Daniel & Zaloumis, Nicholas. (2019). Comment on “The global tree restoration potential”. Science. 366. eaay7976. 10.1126/science.aay7976.

Susan E. Ward,Simon M. Smart,Helen Quirk,Jerry R. B. Tallowin,Simon R. Mortimer,Robert S. Shiel,Andrew Wilby,Richard D. Bardgett.Legacy effects of grassland management on soil carbon to depth. Global Change BiologyVolume 22, Issue 8 p. 2929-2938

Yizhou Zhuang, Rong Fu, Benjamin D. Santer, Robert E. Dickinson, Alex Hall. Quantifying contributions of natural variability and anthropogenic forcings on increased fire weather risk over the western United States. Proceedings of the National Academy of Sciences, 2021; 118 (45): e2111875118 DOI: 10.1073/pnas.2111875118

Zaloumis, N.P. & Bond, W.J. (2016). Reforestation or conservation? The attributes of old growth grasslands in South Africa. Philosophical Transitions of the Royal Society B, vol. 371, 20150310.

Zhang Linlin , Jiangbo Gao, Ze Tang, Kewei Jiao (2021) Quantifying the ecosystem vulnerability to drought based on data integration and processes coupling, Agricultural and Forest Meteorology Volumes 301–302, 108354, ISSN 0168-1923,

Saturday, November 27, 2021

The Vexing Problem of Invasive Ornamental Grasses

Cortaderia  selloana in Virginia 

The use of ornamental grasses has been growing rapidly since the 1970s, when Cortaderia selloana (pampas grass) and Festuca glauca (blue fescue) were the only well known ornamental grasses sold in West Coast retail stores.

It's a different situation today, with ornamental grasses gracing many residential and commercial areas, and even having their own sections in gardening stores.  

But look closely at the selection in many stores and you'll come to realize that many (if not most) of the ornamental grasses are not native to the region in which they are being sold.

Huge Cortaderia selloana on sidewalks in Virginia 

Unfortunately, many people select ornamental  grasses without any consideration about their potential for harming the environment, and  the horticultural industry itself may exacerbate  the problem by continuing to sell plants that have been proven to be invasive. This lack of awareness extends to even reputable botanical gardens and arboretum, and I have repeatedly seen some institutions make heavy use of ornamental grasses like Miscanthus sinensis. Granted, these non-native grasses are often beautiful, but this dependence on such cultivars creates problems due to the potential invasiveness of the species. 

Escaped Cortaderia selloana in Florida

It's not all black and white though. What may be invasive in one region, might be relatively benign in another clime. For example, Imperata cylindrica is one of the most invasive grass in many subtropical and tropical areas in the world, but a red  cultivar (called Japanese Blood Grass)  is relatively harmless in colder areas, even though it can allegedly revert to an all-green invasive form when grown in a more suitable climate.

Large Miscanthus sinensis in parking lot of suburban strip mall in NJ

However, a species that may at first seem non-invasive can become invasive over time. This might have been the case with the popular  Cortaderia selloana (pampas grass) from South America.

Escaped Miscanthus sinensis at forest edge in NJ

This species became very popular in the late 19th century, with society becoming enamored of the large pure white inflorescence and using it almost everywhere. At one point, half a million of the plumes were being sold yearly. But for decades, the invasive nature of C. selloana seems to have been overshadowed by a close relative. C. jubata. In fact, even in the 1970s, researchers reported most of the infestations they found were of C. jubata, and non-cultivated C. selloana did not exist far from human habitation. This seems to have changed by the 1990s, when new surveys showed that C. selloana had become the more invasive of the two, with outcrossing populations found in many different native habitats. Even the morphology of these populations had changed, with the pure white plumes becoming darker.

Arundo donax in an arboretum in NJ

There are sterile options when it comes to non-native ornamental  grasses, including hybrids of M. sinensis. These can be a way out of the trap of desiring particular grasses that have the potential to be invasive, although consumers have to do their research  before buying such species.

In the end, there are several possible solutions to the problem of invasive  ornamental  grasses:

  1. Make it illegal for the retail industry to sell invasive species, and enforce the law.

  2. If possible, sell sterile cultivars of any non-native species.

  3. Continue to inform people about the problems associated with non-native ornamentals, even those that do not seem to be currently invasive.

  4. Promote the use of native ornamental grasses, such as Panicum virgatum, Schizachyrium scoparium, and Andropogon gerardii cultivars. Emphasize not only the environmental reasons for using these, but also their beauty and adaptability.
Only through the rigorous implementation of all these will we be able to make sure we continue to protect the integrity and beauty of our native habitats.

Cortaderia selloana in North Carolina parking lots


Lambrinos, JG (2004). A tale of two invaders. The dynamic history of pampas grass and jubata grass in California. Cal-IPC News. Vol. 12, Nos. 3/4

Friday, November 26, 2021

The Perfect Obsession

New Mexico

I used to pine for the tropics. 

I missed the warm weather and amazing biological diversity that was a common part of my life when I was younger. Many of the things I was passionate about were nowhere to be seen in temperate areas, which was where I found myself the last few decades due to work or family. Thus, I usually had to wait for vacations and trips to find those plants and animals that had grabbed my interest. 

There are temperate aroids here in the East Coast, but none of the large exotic Meconostigma that I specialized in. There are no large banyan trees with their amazing buttresses and surreal aerial roots, nor exotic insects or predatory stomatopods.

It came to a point where I was planning vacations based solely on whether I could spend some time looking for and studying my passion at the time.

New Hampshire

But this all changed when I discovered my fascination with the Poaceae.

Grasses can be found quite literally almost everywhere. They inhabit every continent, including Antartica, and can be found in every type of habitat and ecosystem on Earth. And not just in small ones and twos either, but in many cases in numberless masses that blanket entire fields and hillsides.


So now I can indulge in my fascination with this plant family almost 365 days of the year, although winter does bring with it the near cessation of growth of all vegetation in these norther climes. No longer do I need to miss the beauty of boreal and temperate landscapes because of my near obsession with warmer travels.

I have at last found a perfect obsession, one which rewards my curiosity and desire for learning and discovery each and every day.


Tuesday, November 23, 2021

The Bad-Ass Bamboo Forest in Shang-Chi

Shang-Chi's parents meet with the Bamboo Forest as backdrop for their fight

I just watched the new Marvel movie Shang-Chi on Disney Plus, and I have to say I enjoyed it a lot.

It was funny, the cast was personable and relatable, and the special effects were fantastic. The movie has a 92% rating at, and it broke several box office records during its release.

But two scenes in particular made me really like the movie.

The mother of Shang-Chi comes from a village called Ta Lo, which is filled with magical beasts from Chinese folklore. This village is guarded by a bamboo forest, which forms a beautiful backdrop for a fight scene between the hero's parents when they first meet.

The bamboo in the forest also can move, and they have a penchant for wanting to squash intruders who try to find Ta Lo.

This awesome behavior is in full view in two different car scenes, where the maze-like forest opens up in front of rushing cars, only to close violently behind them. Anyone not fast enough to outwit and outrun the closing forest is smashed into bits and "eaten".

Fiction books and movies are replete with hostile plants, but this variation on the theme was entertaining and unique, and I highly recommend the movie to everyone. Enjoy!

Official Trailer:

Saturday, November 13, 2021

Wild on Ornamental Switchgrass (Panicum virgatum)

I admit I am a sucker for Panicum virgatum ornamental grasses.

I think it all started when I read The Obsessive Neurotic Gardener, a gardening blog whose author was particularly enamored of ornamental grasses.

He introduced me to a cultivar called P. virgatum 'Northwind', which not only has metallic green leaves, but looked quite stunning because it grew straight up and did not tend to flop after awhile. 

P, virgatum "Northwind"
I bought  one of these 2 years ago and it was indeed a beauty, with seemingly iridescent blue green  leaves that stood straight as an arrow.  This cultivar was introduced by  Roy Diblik of Northwind Perennial Farm, Lake Geneva, WI, and in 2014 it won the Perennial Plant of the Year, awarded by the Perennial Plant Association. I have seen it stand up to very strong winds, the thin blades not bending to the force of the storm.

"Thundercloud" to the left, and "Northwind" to the right

I also bought one of the crosses made using P. virgatum " Northwind" (with the tall cultivar P. virgatum "Cloud Nine") by Hoffman Nurseries, one of the premier ornamental grass suppliers here in the USA. 

P. virgatum "Thundercloud" attains a height of about 2.5 meters, with bluish leaves and the usual airy cloud of panicles. I got it this Spring, and it shot up to 1.3 meters this year (1.5 m with the panicles), easily overshadowing the more diminutive "Northwind". I can't wait to see how it does next year, although I have some concerns about the availability of growing space!

P. virgatum during winter

The largest ornamental grasses in our neighborhood are various cultivars of the non-native Miscanthus  sinensis, although one home seems to have a group of Saccharum ravennae as an unusual addition to their front lawn. But native ornamental grasses like P. virgatum are just as attractive and are certainly just as hardy, and I hope their popularity continues to grow.

Saccharum ravennae

Monday, November 8, 2021

How Lawns Might Affect the Perception of Prairies

Many Americans hate lawns, for various reasons. 

Perhaps their belief is based on the notion that lawns are bad for the environment, whether it's because of the chemical runoff inevitably created by their maintenance, the inordinate waste of water to sustain them, or the lack of biodiversity and havens for pollinators. But many other people, perhaps the majority, are either supportive of lawns, or at least apathetic to the social and even legal requirements that homes should maintain a cut clean lawn on their front yards.

I've sometimes wondered whether such viewpoints could be a factor in the way this one segment of society might view prairies. In this case, lawns may have a negative impact because the ideal and perfect lawn in their minds is the complete antithesis of a prairie. Lawns are  basically  human-maintained prairies where all the multitudes of plant and animal species have been stripped away and discarded, leaving behind just a few desirable grasses.

When they see a prairie, this notion of an idealized lawn could (even if subconsciously) blind them to the truth. Instead of seeing the amazing biological diversity contributed by the many forbs and other plants, they see "weeds"; instead of marveling at the animals that make the prairie their home and add to the wonderful complexity of food webs, they see "pests"; and instead of being awed by the tall grasses they see an unmown landscape.

What a tragedy, if this is the case!

Sunday, October 31, 2021

Picture of the Day: Konza Prairie in Autumn

 Image courtesy of Jill Knutson Haukos

The Konza Prairie Biological Station is a protected area of native tallgrass prairie in the Flint Hills of northeastern Kansas. "Konza" is an alternative name for the Kansa or Kaw Indians who inhabited this area until the mid-19th century. The Konza Prairie is owned by The Nature Conservancy and Kansas State University.

For more information on this beautiful Tall Grass Prairie, click here.

For information on visiting, click here.

Friday, October 29, 2021

Why aren't there more grass plant nerds?

Schizachyrium scoparium inflorescence

 I am a plant nerd.

At various times in my life I have become obsessed with different plant groups, whether aroids, or banyan trees, or palm trees, or even the occasional foray into orchids. In that long time span I have become familiar with my fellow plant nerds, and the reasons why they have become enamored of their chosen plant group. Most are gardeners and collectors, and love to grow and take care of the plants; some are researchers, and some have even taken their passion and created a business out of it.

The reasons why they focus on a particular plant group are also varied. Perhaps the plants have gorgeous and strange flowers like orchids, or amazing leaves and inflorescences like the aroids. Perhaps the plants remind them of exotic things, like palm trees, or perhaps they are rare and thus of much value.

Grasses as a whole don't seem to normally engender such feelings among plant nerds, with the possible exception of bamboos. Poaceae flowers are usually minute things, and their leaves are relatively similar within the family. Grasses are not rare, and in fact are so successful and abundant that they have become an unremarked part of our environment. People collect and grow aroids and orchids in pots and their gardens, but it's unlikely that plant nerds would keep potted grasses (though I have kept a potted Japanese Blood Grass, a nerdy act if there ever was one!). The fact that they are relatively hard to identity to species also scares off a lot of people.

And yet within the grass family there are remarkable species that are worthy of being the focus of plant nerds. Grasses that have wonderfully fascinating adaptations or are rare and endemic. Grasses like Swallenia alexandrae, the Eureka Dune Grass, which is only found in a few isolated dunes in the vast barren wastelands of Death Valley in California; or the beautiful vining bamboo Chusquea delicatula, found only in the highlands near the ancient Incan city of Machu Picchu; or even the strange and oil-exuding Orcuttia grasses that live in transient vernal pools and don't seem to have any affinity at all with other extant grass species. These and others will be some of the species I hope to feature in my future posts, and which I hope to encounter in situ going forwards.   

Spider on Cenchrus purpureus

Tuesday, October 26, 2021

The Fight to Create a New Paradigm of Old Growth Grasslands

An updated version of this post is in the Missouri Prairie Journal (pdf)

The recent fight to save a remnant Prairie called Bell Bowl Prairie in Illinois has driven home (again) the precarious state of the world's ancient and pristine grasslands.

One major factor in the lack of focus about the dangers to this biome (as opposed to, for example, the rainforests) is the fact that many people still cling to the view that grasslands are simply a transitional or 'arrested' state towards becoming a forest. The belief that grasslands are low diversity, degraded land that had once been forests, or are "empty" land that could be used for something better, is one that has repeatedly been used to justify the destruction of this biome in history.

However, there has been a recent push by grassland researchers and proponents to combat this perception by pushing the notion of the so-called "Old Growth Grasslands", which is comparable to the traditional "Old Growth Forests".

What are Old Growth Grasslands?

The term Old Growth Grasslands (OGG) is relatively new, and refers specifically to grasslands that are characterized by having:
  • Ancient history and heritage, as opposed to being so-called secondary grasslands that just recently arose from human degraded forest or other land. For example, the plant lineages making up the Cerrado in South America started assembling almost 10 million years ago, long before our species even evolved.
  • High biodiversity compared to secondary grasslands. In fact, some old growth grasslands boast the highest plant species diversity in the world.
  • Very slow rate of recovery when destroyed due to agriculture, plantation forestry, and other human activities.  An Old Growth Grassland may take centuries and even millennia (projected 1400 years!) to recover its former species richness when it has been degraded to secondary grassland.
The term '"Old Growth" is made synonymous with words like ancient, intact, native, natural, pristine, reference, remnant, semi-natural, and undisturbed.

What is the problem?

There is a widespread perception among people that grasslands (including OGG) are simply degraded forests whose successional development has been arrested by disturbances such as fire and herbivory. 

Policies to combat climate change and protect biodiversity have often ignored the protection of these ancient grasslands, and in many cases have actually caused their destruction via deliberate tree-planting on pristine grasslands (afforestation)

What is the goal?

We must help change the widespread perception that old growth grasslands are simply degraded forested areas and a mere transitional stage towards becoming forests. This change in viewpoint will hopefully give this ancient biome a value and protection equal to rainforests and other old growth forests.

What is happening to Old Growth Grasslands?

The old growth grasslands have been and are still one of the most threatened ecosystems in the world, and in fact we have lost and are losing ancient grasslands at a pace that is significantly more rapid than loss of forests.

A few examples:

The majority of old growth grasslands in the USA has been lost, and only isolated remnants remain. For example, up to 99% of all Tall Grass Prairies in the country is gone, and only isolated remnants remain. Other grassland types are not faring well either. In one year alone (2018-2019), the Great Plains lost 1.1 million hectares, which is an area greater than Yellowstone National Park.

Half of the Brazilian Cerrado has already been cleared for agriculture expansion, and up to a million hectares is cleared each year. This is the equivalent of wiping out an area the size of New York City every month!

More than half the Pampas of South America have been lost to agriculture and cattle breeding. The remaining 50 million hectares of these grasslands are still being decimated, and are home to 540 recorded wild bird species, 12 of which are globally threatened.

The recent trend of planting trees to combat climate change has also caused widespread problems, when trees (and especially weedy invasive species) are planted in pristine grasslands ("afforestation") instead of degraded areas. 

Why must we fight for Old Growth Grasslands?

1. The old growth grasslands are the most biodiverse environments in the world at many scales.

For example, a mountain grassland in Argentina had an absolutely amazing 89 vascular plant species packed into a single square meter, a more diverse plant assemblage than one can see even in rainforests. 

Old growth grasslands are also significantly more diverse than secondary grasslands, having around 37% more species on the whole. When this diversity is degraded, it takes centuries or millennia (projected)  for the OGG to reassemble as diverse a community.

2. Old growth grasslands provide a home for innumerable species of animals. The destruction of old growth grasslands affects all the animals that depend on this habitat. 

For example, the total population of grassland birds in North America has dropped an astonishing 40% since 1966. One-third of all grassland bird species are on the Watch List due to steeply declining populations and threats to habitat. Birds that breed in the Great Plains of Canada and the U.S. and winter in Mexico’s Chihuahuan grasslands are experiencing exceptionally steep declines, a nearly 70% loss since 1970. Other temperate grassland birds have declined by 33% in that time.

Old growth grasslands also support numerous rare and endemic species. For example, the savannas of the South American Cerrado support 4,800 endemic plant and vertebrate species, all of which could be threatened by the continued decimation of this biome.

3. Grasslands play an essential role in combatting climate change. 

Grasslands store approximately 34 percent of the global stock of carbon in terrestrial ecosystems while forests store approximately 39 percent and agroecosystems approximately 17 percent. 

Some studies have shown that grasslands are an even more reliable carbon sink than forests, and although grasses account for only 3% of plant species on Earth, grass-dominated landscapes contribute 33% of global primary productivity, the amount of CO2 removed from the atmosphere every year to fuel photosynthesis.

4. Grasslands collect freshwater for most of the largest rivers of the world. 

For example, the Cerrado in Brazil delivers 40% of all the freshwater in that country! 

5. Possible conversion to secondary grasslands.

The loss of old growth grasslands due to conversion to human agricultural use or due to misguided attempts at afforestation frequently results in the rise of secondary grasslands in their place. Such secondary grasslands are less diverse and usually very fire prone (which creates new dangers to human communities and forests). For example, one major factor in the recent huge and destructive fires in the West Coast of the USA is the proliferation of invasive annual grasses, which have supplanted the perennial grasses and shrubs after degradation of the land due to over-grazing.

What can you do?

Champion and spread the concept of Ancient or Old Growth Grasslands, which are separate from secondary grasslands, and are equally as old and biodiverse and worthy of protection as Old Growth Forests.


Bardgett, R.D., Bullock, J.M., Lavorel, S. et al. Combatting global grassland degradation. Nat Rev Earth Environ 2, 720–735 (2021).

Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N., Rodenbeck, C., Arain, M. A., Baldocchi, D., Bonan, G. B., Bondeau, A., Cescatti, A., Lasslop, G., Lindroth, A., Lomas, M., Luyssaert, S., Margolis, H., Oleson, K. W., Roupsard, O., Veenendaal, E., Viovy, N., Williams, C., Woodward, F. I. & Papale, D. (2010). Terrestrial gross carbon dioxide uptake: global distribution and covariation with climate. Science 329,

Colli, G.R., Vieira, C.R. & Dianese, J.C. Biodiversity and conservation of the Cerrado: recent advances and old challenges. Biodivers Conserv 29, 1465–1475 (2020).

Comer, P. J., J. C. Hak, K. Kindscher, E. Muldavin, and J. Singhurst (2018). Continent-Scale Landscape Conservation Design for Temperate Grasslands of the Great Plains and Chihuahuan Desert. Natural Areas Journal 38:196–211.

Dass Pawlok, Benjamin Z Houlton, Yingping Wang, David Warlind. Grasslands may be more reliable carbon sinks than forests in California. Environmental Research Letters, 2018; 13 (7): 074027 DOI: 10.1088/1748-9326/aacb39

Intergovernmental Panel on Climate Change (IPCC), August 2019. The Special Report on Climate Change and Land (SRCCL), a special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.

Murray S, M. Rohweder, R. White (2000). Pilot Analysis of Global Ecosystems : Grasslands Ecosystems.

Nerlekar, Ashish & Veldman, Joseph. (2020). High plant diversity and slow assembly of old-growth grasslands. Proceedings of the National Academy of Sciences. 117. 201922266. 10.1073/pnas.1922266117. 

Simon Marcelo F., Rosaura Grether, Luciano P. de Queiroz, Cynthia Skema, R. Toby Pennington, Colin E. Hughes (2009). Recent assembly of the Cerrado, a neotropical plant diversity hotspot, by in situ evolution of adaptations to fire. Proceedings of the National Academy of Sciences Dec 2009, 106 (48) 20359-20364; DOI: 10.1073/pnas.0903410106

Veldman, Joseph W. “Clarifying the confusion: old-growth savannahs and tropical ecosystem degradation.” Philosophical transactions of the Royal Society of London. Series B, Biological sciences vol. 371,1703 (2016): 20150306. doi:10.1098/rstb.2015.0306

Wilsey, CB, J Grand, J Wu, N Michel, J Grogan-Brown, B Trusty (2019). North American Grasslands. National Audubon Society, New York, New York, USA

Wilson, J. Bastow; Peet, Robert K.; Dengler, Jürgen; Pärtel, Meelis (1 August 2012). "Plant species richness: the world records". Journal of Vegetation Science. 23 (4): 796–802.

World Wildlife Fun. (2021).  PlowPrint Report 2021

Thursday, October 21, 2021

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.

Monday, October 18, 2021

How an Invasive Grass Secretly Spread and Eluded Eradication

Tiny spikelets of Oplismenus undulatifolus

The insidious invader first came to light in 1996, in Patapsco State Park in Maryland, and by 2004 it had leapt into the next state and was discovered infesting a large area in Virginia's Shenandoah National Park. Efforts to eradicate it while it had a limited distribution began in earnest, but fifteen years later, it had spread to thousand of hectares in Maryland, Virginia, and even one spot in Pennsylvania. 

The distinctive wavy leaves of O.undulatifolius

The ability of Oplismenus undulatifolius (Wavyleaf Basketgrass) to defeat all efforts to halt its advance was likely due to several factors.  The first is its long lived perennial nature, an attribute different than a congener, the also invasive Microstegium vimineum (Stiltgrass). This allows it to push up from thick litter every year using well developed roots, unlike the latter, which has to germinate from more vulnerable seed every year.

The second factor is the ability of this understory species to thrive in very dim light. One study found that it could still grow in as low as 2-11 mols m2 per day of light. This allows it to exist within the forest interiors, and thus escape the attention of many biologists and others who usually do not wander far from trails. 

Stigma of Wavyleaf Basketgrass

The third factor which allowed Wavyleaf Basketgrass to thwart attempts to contain and eliminate it was a characteristic that was in full display when I chanced upon a small cluster of this invader near Shenandoah National Park yesterday.

I saw what looked to be tiny beads strung along 5 to 10 cm spikes that shot out from the masses of wavy leaves. Each bead was perhaps 1 or 2 mm in diameter, with sharp awns projecting from them.

When I used my macro lens to view the beads, I suddenly realized these were flower and seedheads!

Awns with sticky liquid

Under the macro lens, the spikelets of this grass looked like alien spaceships, with the awns decorated with beads of liquid.

It turns out that O. undulatifolius disperses its seeds using unwitting animals, with the sticky liquid enabling them to attach to the fur or shoes and socks of passing fauna. Wavyleaf Basketgrass is a prolific producer of these sticky seeds, with dense stands developing more than 6000 seeds per square meter every year. It is such a profligate invader that Prof. Vanessa Beauchamp found that a dog running through this grass could pick up 12000 or more seeds on its fur! People are also used as vehicles for dispersal, with one study showing that around 800 seeds adhered to fleece within 30 seconds, while even denim pulled in around 300 seeds within the same timespan!

Given all these attributes, it is certainly understandable why all attempts to eradicate the invasive grass have so far proven futile. But if you are out hiking and find this, then be sure to report the find in order for us to at least contain it.


Beauchamp, Vanessa B.; Koontz, Stephanie M.; Suss, Christine; Hawkins, Chad; Kyde, Kerrie L.; Schnase, John L. (2013). "An introduction to Oplismenus undulatifolius(Ard.) Roem. & Schult. (wavyleaf basketgrass), a recent invader in Mid-Atlantic forest understories". The Journal of the Torrey Botanical Society. 140 (4): 391–413.

Peterson, P.M., E.E. Terrell, E.C. Uebel, C.A. Davis, H. Scholz, and R.J. Soreng. 1999. (Scientific Note) Oplismenus hirtellus subspecies undulatifolius, A new record for North America. Castanea 64:201-202.

Thursday, October 7, 2021

Elymus hystrix: Spiky Angel

This is probably one grass species that you will easily recognize.

It has amazing looking spikelets that look sharp and pointy - perhaps sharp enough to to prick your thumb, though I did not try.

I encountered it during a NJ hike in July 2020, in a somewhat shaded location next to a river.

I later identified it as Elymus hystrix, and it is a species that likes filtered light and nearby water, which describes exactly the location of the specimen that I found.

E. hystrix is called Eastern bottlebrush, due to the overall shape of its inflorescence. Its specific epithet is from the Greek hystrix, which means "hedgehog", an apt moniker given the spiny looking spikelets. It's a perennial grass and can self-pollinate, which I assume is a trait that is sometimes useful when one is separated from the rest of the population.

The specimens I encountered were huddled amongst the other vegetation, just native plants blending in with the crowd. It was such a difference from (for example) Taeniatherum caput-medusae (medusahead grass) or Imperata cylindrica (Cogon grass), both of which exist in dense clusters that exclude most other species. 

Cogon grass existing in very dense clusters

I admit I like it. It's a clean looking native species with an unusual and readily identifiable inflorescence (always a boon to a noobie like me who has trouble identifying graminoids) and perhaps I'll see it again during hikes in the Shenandoah area this month.