Tuesday, July 26, 2022

Sandburs aren't 'Evil'

I was observing some of the grasses in Sandy Hook Beach, NJ last week, when I chanced upon some weird looking seedheads in the sand. They looked like round pods, but with sharp thorn-like protrusions decorating the surface.

I had briefly encountered this species before, but now I took some time to photograph it. Unfortunately, I did not have my macro lens with me, but the structures were large enough that I could get good enough pics.

Cenchrus longispinus is an annual whose spikelets are enclosed in tough, spiny burrs. These burrs can float, and dispersal by water is one way the grass spreads its seeds. The barbs that sprout out from the shell also aid in dispersal, as they can latch onto passing animals or the clothes and shoes of people. Unfortunately, the sharp spines are also quite capable of piercing human skin, and I can only imagine what it would be like to be walking on a sandy beach and suddenly step on a bunch of these well-protected propagules.

Indeed, a quick read of some of the articles on this grass will tell you just how much people loathe it. The word "evil" in particular is used a lot when describing sandburs, which is rather undeserved given that the definition of the term is that it is "profoundly immoral and wicked". In my opinion, this is something which should never be ascribed to animals or plants that are simply doing what they do to survive. There is likely no conscious desire on the grass to hurt people, or even to inconvenience or bother anyone. To it, we are simply nothing more than transportation for its progeny, and it neither wishes us harm nor well-being ;-)

Saturday, July 23, 2022

How many blades of grass in the world?

 Note: I welcome corrections to my calculations. Math was not exactly my best subject!

How many blades of grass in the world?

This is a question sometimes asked by people, and one which seldom gets any answer.

In fact, it's near impossible to resolve this question, with one major factor being that different species of grasses can attain different final maximum densities.

However, it is fun to calculate the number of blades of grass for narrower and more limited scenarios.

For example, would it be possible to calculate the total number of blades worldwide for a single species?

In this case, we would need to know 2 things: The density per given square area of that species, and the total area covered by the grass worldwide.

Only a few grass species have had their total coverage area estimated by researchers, and one of those is the aggressive Imperata cylindrica (cogon grass). There are some estimates that this species may cover as much as 500 million hectares worldwide, although the veracity of this staggering number is open to question.

Nevertheless, if we take this number as a given, and add in potential densities of cogon grass blades (0.25 per square cm or 2500 blades per sqm), then we quickly get really large numbers.

Since there are 10,000 sqm per hectare, then 1 hectare of cogon grass can have around 25 million blades of the grass. Multiply this by 500 million hectares and you get the absolutely huge number: 1.25 x 1016 blades of cogon grass in the world!

In order to put that number in perspective, if we take the current human population of the world at 7 billion people, then there would be almost 2 million blades of cogon grass for every single person.

Or to put it another way: if you lined up each cogon grass blade every meter in a straight line, you would get a line of plants that stretched 12.5 trillion km, or an absolutely mind boggling 1.3 light years! The distance from the sun to Pluto is only 5.9 billion km, so you could potentially have more than 2100 lines of cogon grass blades stretching from the sun to Pluto!

Imperata cylindrica (cogon grass) in flower

Now we can take it even one step farther, and examine a "fictional" situation.

How many blades of grass would there be if a species of grass covered all the land area in the world?

The winter annual invasive Taeniatherum caput-medusae (medusahead grass) has been seen to have as many as 21,500 plants per square meter, which comes to around 21.5 billion plants per square km. Since total land area of the world is approximately 130 million square km, then if this species covered the entire earth, then we would be talking about 2.795x1018 plants

To put this number in perspective, this would be about 400 million medusahead plants for every person in the world

Or to put it another way: if you lined up each medusahead grass every meter in a straight line, you would get a line of individuals that stretched 2.795e+15 km, or an absolutely mind boggling 288 light years! The distance to the nearest star Alpha Centauri is only less than 5 light years.

Taeniatherum caput-medusae (medusahead grass)
Such amazing numbers mean that grasses are likely the most populous meter-scale organisms on the planet today!


Sharp, Lee A.; Hironaka, M.; Tisdale, E. W. 1957. Viability of medusa-head (Elymus caput-medusae L.) seed collected in Idaho. Journal of Range Management. 10: 123-126. [2118]

Torell, Paul J. 1967. Dowpon--an aid to reseeding medusahead-infested rangeland. Down to Earth. 23: 6-8. [6005]

Sunday, July 17, 2022

Now, THAT'S a front yard!

Google Street View in May 2022

We were on our way to a hiking location here in North New Jersey, and  on the way we passed by some fairly upscale communities. Most had wide front lawns, the grasses kept immaculately low to the ground, with occasional homes sporting large ornamental grasses like Miscanthus sinensis and Calamagrostis cultivars.

But suddenly, I gasped and pointed at something to my fellow passengers in the car. One of the houses had a front yard that was absolutely wild. Lots of tall stately grasses waved in the wind, and there were so many of the tall grasses and shrubs and forbs that the house itself was almost obscured from view.

Unfortunately, we did not have time to stop, but I made a quick mental note of some landmarks around us. When I got home later, I used google street view to try to find the home again, although I was thinking it was a long shot. But amazingly enough, the house front yard was so distinctive I actually did manage to locate it! 

The google street view image was from spring of this year, so the plants were not as high as they are now, and thus not as majestic. But there was no doubt that I had found the right house.

I thought it was charming and daring of this homeowner to go against the grain by not using the usual turf grasses, and I liked the overall effect. But one of my passengers had exclaimed "It's like a jungle!" 

Oh well, you can't please everyone!

UPDATE (2022-07-23)

I managed to take a pic of the front lawn as it looks now, and it looks great. Sorry for the quality of the photo, but I was just using my smartphone at the time. Love the masses of Calamagrostis!

Friday, July 8, 2022

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.

Saturday, July 2, 2022

Top of the World, Ma!

I visited Olympic National Park in Washington State last year, and the subalpine meadows on its tall peaks drew us in. The open tree-less spaces, the snow-covered mountain heights in the distance, the ground hugging grasses and forbs. I would not trade this vast panorama for any of the closed humid spaces down below.

This is a place where your soul can soar.