An Enchanted Hike Through the Enchanted Mesa

Tall flowering grasses line the path

I could spend tons of posts on the beauty that we saw when we stayed in the Boulder, Colorado area this last summer, but one of the more notable periods of our stay was when many of the so-called wheatgrasses were in flower.

The Enchanted Mesa trail in the Flatirons hiking area is considered a moderate trail, but I remember it was relatively easy and flat. You also get some good spectacular views along part of the way.

The arching flowerheads of T. intermedium

But the best part of hiking this trail is that large parts of it lie in savanna grassland, and in mid-July, the path is lined by masses of tall flowering grasses. 

These include the wheatgrasses Pascopyrum smithii and Thinopyrum intermedium, whose arching flowerheads are positively ethereal against the filtered sunlight, as well as the usual Bromus inermis.

I was accompanied by my wife in the hike, and although she is not a die hard grassophile like myself, even she had to marvel at the scenery and comment on it.

In fact, many of the hiking trails in the area had the same grasses in flower, and another notable hike that we did was at the Red Rocks trail. 

Red Rocks Trail in July 

In this case, the sight of the ancient red rocks rising above the flowering grasses that surrounded them was almost a religious experience, especially with the grasses dancing in sinuous waves to the gusting wind.

So the next time you're in the Boulder area in July, be sure to lace on your hiking shoes and take an enchanted trip to the Enchanted Mesa!

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How I do botanical backgrounding in photographs

Cynodon dactylon (Bermuda grass) in Parque del Amor, Lima, Peru. The beach is down below a cliff, and you can see the waves as they rush to shore.

Note: I am by no means an expert at photography, so apologies for any mistaken notions I may have, but here are a few things I've learned.

I am a big fan of macrophotography, and I have been doing it for several years now.

But sometimes I want to show more than just the specimen, especially when the picture I am taking includes scenery that is well known or significant.

In this case, my goal is to have a sharp foreground showing the specimen(s), but with a soft blurry background that does not take away the scenery completely. In order to accomplish this, you need to create something called a shallow depth of field. 

Bromus tectorum (cheatgrass) in foregound of Continental Divide scenery in Rattlesnake Gulch Trail, El Dorado State Park, Colorado, USA.

Creating this shallow depth of field is more an art than a science, and it involves fiddling with various settings in your DSLR camera, as well as correctly positioning yourself and your subject.  This includes:

1. Aperture

This refers to the amount of light that reaches the camera sensor, and the metric it uses is called the f-stop. The lower the f-stop, the greater the amount of light that reaches the sensor, and the shallower the depth of field (the blurrier the background). 

For example, an f-stop of 3 means more light gets to the sensor, which creates a shallower depth of field than if the f-stop is 9. So using an f-stop of 3 would get you a blurrier background compared to using an f-stop of 9, all other things being equal.

Dactyloctenium aegyptium in foreground and our cruise ship in background (in Costa Maya, Mexico)

2. Focal length 

This refers to how wide your angle of view is, and it also affects the magnification. It is measured in millimeters (mm), and the rule of thumb is that the longer the focal length, the greater the magnification, the narrower your field of view, and the shallower the depth of field (the blurrier the background).

So, a focal length setting of 100 mm provides greater magnification, a narrower field of view, and a shallower depth of field than a lens with a focal length of 20 mm.

Bouteloua dactyloides (Buffalograss) in foreground of Buffalo Bill sculpture in Oakley, Kansas.

3. Distance between camera and specimen

There are also things you can do beyond just fiddling with your camera settings to create a soft blurry background and a sharply focused subject. The distance you keep between your camera and the actual specimen also makes a big difference.

The smaller the distance between the camera and the specimen, the shallow the depth of field (the blurrier the background). 

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

Putting all these factors together, the golden rule of botanical backgrounding therefore is:

In order to get a shallower depth of field (blurrier and softer background) while maintaining a sharp focus on the specimen, you need a lower f-stop, a higher focal length, and a shorter distance between camera and specimen.

Here's an example of how focal length, aperture, and distance to the specimen can affect the depth of field and how blurry the background gets using the same specimen and background.

In the first pic below, the specimen is Avena barbata, with the Moras Salt Mines in the Sacred Valley of Peru in the background. The f-stop used here is 8, the focal length is 20 mm, and I was standing relatively far away from the specimen when I took the pic. Notice how relatively clear the background is when compared to the actual subject of the photo. This makes the picture too "busy", and detracts from the focus of your photograph, which is the grass in the foreground.

Avena barbata (?) in the Moras Salt mines in the Sacred Valley of Peru

Now compare that picture above with the picture below. This is the same specimen, but this time I am using an f-stop of 2.8, a focal length of 100 mm, and I am closer to the specimen. Notice how relatively clear the specimen is, but how blurry the background has become. Normally, I would not want a photo like this when I'm doing botanical backgrounding of my photo (too shallow a depth of field and thus too blurry in back), but it does illustrates how aperture, focal length, and distance to the specimen heavily influences the depth of field and the contrast between subject and background. 

It also highlights how much of an art it is trying to get a good optimal mix between a too-clear background that steals focus from the subject, and one that is a completely unrecognizable blur.  

Avena barbata (?) in the Moras Salt mines in the Sacred Valley of Peru

Sounds relatively simple right? Now good luck with your pics, and I hope this short article helps you when you are taking botanical photographs and want a good background for it.

My camera is a Nikon D3400, and for macrophotography I use a Tokina AT-X pro lens.

ps.

I should note that taking the types of backgrounding pics where the specimen is very close to the ground means more than just worrying about focal length, aperture, and distance to specimen. Most times I need to lie flat on the ground to take pics, or take "blind" pics (taking pics without looking into viewfinder) after adjusting the settings, hoping for a photo that is in focus. Someone mentioned that there is visual equipment that will allow you to take pics while holding the camera at awkward angles, but I don't have that (yet). In the meantime, this is hard work and not as easy as I make it out to be above. 

Cogon in Colorado: An Alarming Case of Natural Reversion from the Ornamental Variety

Click here for a new update to this article.

The highly aggressive Imperata cylindrica is normally considered an invasive weed, but it is sold as an ornamental in some places due to an attractive variety called Japanese Blood Grass or Red Baron.

This variety has reddish leaves and is significantly smaller than the wildtype form. It is also notably less competitive than the latter. In addition, flowering in this variety is extremely rare, and it is cold tolerant. 

Ornamental form in New Jersey

The problem with the ornamental variety is that it has been shown to revert to the aggressive green form under certain environmental conditions, and so this variety cannot be sold, traded, or grown in certain states that have major cogon grass problems. The fear is that it might hybridize with the green form to form very aggressive, and cold tolerant, varieties that can become problematic even in cooler areas.

Cogon grass stand in Broomfield, CO. The dense mass has started to insinuate itself into the nearby shrubbery.

Natural conversion from the ornamental to the green form is probably very rare, and in the many years that I have known it in New Jersey, I never encountered such an event. However, I was walking along a street in Broomfield, CO, when I had to do a double take and take a closer look at a stand of grasses. Rising from the dense mass were flowerheads that looked similar to the distinctive inflorescence of I. cylindrica. 

Spent flowerhead

Most had already lost their spikelets, but a few still had the characteristic fluffy white seeds of the species sticking to them.

White hairy seeds of I. cylindrica from the reverted stand

There was no trace of red blades in the stand, and the grasses were up to more than 1 meter tall, which is significantly taller than I've ever seen the ornamental variety grow. All indications pointed to the fact that these were wild type cogon grass. In fact, the stand looked exactly like any cogon grass stand in Florida, the dense mass almost excluding all other plants from living in it.

Spent flowerhead with a few fluffy seedheads still attached

I surveyed the area and found at least two stands of reverted cogon grass in the vicinity. In the second stand, there was a mixture of both ornamental and green forms, with the green forms sprouting multiple flowerheads as well. In both stands, a few other plants managed to hold onto their spots, including Bromus inermis, which is normally one of the dominant naturalized exotics here in the Boulder area. Most will probably succumb to the much denser and more aggressive I. cylindrica over time.

Dense mass of reverted Cogon grass fills up all the available space. The brown flowerheads to one side are from a few Bromus inermis that have survived in their midst

Broomfield, CO is definitely not a subtropical or tropical location, so to say that I was surprised to find green-form cogon grass in the place would be an understatement. The ornamental variety of cogon grass seems to be used here though, probably because the assumption is that the cold and snow would keep it in "safe mode".

The reverted wild type form is significantly taller than the ornamental form, and is green in color.

However, the record heat prevalent in the southwest right now is probably increasing the average temperature in this area as well. Add in the wet winter and spring this year, and conditions might be optimal enough for the ornamental variety to revert. 

Ornamental form between Calamagrostis spp.

The origin of the cogon grass is likely ornamental forms that had been planted along the sidewalk. I found a couple of these sandwiched in between the usual Calamagrostis ornamentals. 

The question on whether these naturally-reverted forms will continue to survive is important. Will the cold and winter of Colorado convert these back to the ornamental form going forward, or will the warming climate allow it to flourish and start aggressively taking over swathes of the environment?

Time will tell.

Note: I have contacted the relevant authorities who can handle these clusters, so they will probably be extirpated going forward.

Unlikely pairing of Bromus japonicus and Imperata cylindrica "Japanese Blood Grass"

The Case for Urban Open Spaces

Bouteloua dactyloides staminate spikelet (from another location)

One of the first things I noticed here in Colorado is the prevalence of land called "Open Spaces". These Open Spaces are preserved land that is not developed, although they may be adjacent to the usual parks and other recreational locations.

According to the department that manages these areas in the city of Boulder:

The open space lands teem with native plants and wildlife and are home to threatened and endangered species. They serve as a buffer between Boulder and nearby development. They sustain agriculture uses and add untold benefits to the natural environment - clean air, water, and earth. The lands shape the urban mosaic of the Boulder Valley and provide residents with passive recreation opportunities. Trails are used by walkers, hikers, bicyclists, horseback riders, dog walkers and other passive recreational uses.

I visited one of these Open Spaces in nearby Broomfield, which has kept their city beautiful by preserving large tracts of land. In the Open Space that I visited there, walking paths crisscrossed the place, and people were jogging, walking their dogs, and generally just enjoying nature. I did some botanizing one morning, and found many native grasses, although they were outnumbered by the usual naturalized exotics that have become ubiquitous wherever humanity has taken hold.

Part of an Open Space in Broomfield, CO

I spent  an enjoyable morning just walking the paths and looking at the critters, and managed to identify some of the major species during my botanizing. As always, I am always open to corrections of my identifications.

One of the most notable denizens of the area was Bromus inermis, which existed in large clusters and is commonly called Smooth Brome. You can identify it not only by the recognizable spikelets and habit, but by a W crimp in the middle of the leaves. This species is an introduced forage grass, but it has become somewhat invasive in many places.

Bromus inermis

The native Pascopyrum smithii (called Western Wheatgrass here) was also quite abundant. It is rhizomatous, and so exists in the area in large groupings.

Pascopyrum smithii

Close to it I also saw Thinopyrum obtusiflorum, which looks somewhat similar, but is significantly taller than its neighbor. This species is not native, but had been introduced from Eurasia. It has a few common names, such as tall wheatgrass, rush wheatgrass, and Eurasian quackgrass.

Thinopyrum obtusiflorum

Another naturalized Eurasian species was also quite abundant. Agropyron cristatum is called crested wheat grass, and the sight of its flowerheads en masse was quite attractive.

Agropyron cristatum

There were also stands of what I first took to be escaped cultivated plants. but which may instead be a native called Hordeum brachyantherum (meadow barley). These were one of the taller species in the community, dwarfing everything but some of the Thinopyrum obtusiflorum specimens.

Hordeum brachyantherum

The smaller species I found along the sides of the path, and included native grasses from the genus Bouteloua (which has become one of my fav genera, and which I'll explore more in a later article).

Bouteloua gracilis (called Blue Grama grass here) was in evidence along the margins, their distinctive flowerheads dangling bright green anthers. This species is one of the dominant inhabitants of the short grass prairies in Eastern Colorado.

Bouteloua gracilis

I also found some specimens of the equally diminutive Bouteloua dactyloides (called buffalo grass here), another dominant species of the short grass prairies that has been used as turf. More on this later, but it is one of the few dioecious grasses, with some individuals having only staminate flowers,  and others only pistillate flowers.

Bouteloua dactyloides (staminate spikelet)

Other species that I found included the natives Panicum capillare, Bouteloua curtipendula, and Hordeum jubatum, as well as a few clusters of the invasive Bromus tectorum. In a creek, I even found a lone cattail (Typha sp, not Poaceae) surrounded by the invasive Phalaris arundinacea (Reed Canary Grass).

Phalaris arundinacea surrounds a lone cattail (Typha sp)

The variety of species was fantastic, and I loved the time I spent botanizing. All in all, I have to say that I am fully and heavily in support of creating such Open Spaces. I would rather see natural areas like these preserved, than more gated communities, mini-malls, McMansions and parking lots. 

As noted above, some of the advantages include:

• They serve as home to threatened and endangered species.
• They serve as a buffer between a city and nearby development.
• They sustain agriculture uses and add untold benefits to the natural environment - clean air, water, and earth.
• The lands shape the urban mosaic and provide residents with passive recreation opportunities. Trails are used by walkers, hikers, bicyclists, horseback riders, dog walkers and other passive recreational uses.

In addition, I believe Open Spaces give an airy and open vibe to a city, provide habitats for a large variety of plants and animals, and serve as a shining example of how nature and people can coexist together.

Kudos to the city of Broomfield, Boulder, and all the other enlightened communities in Colorado that have the foresight and the perseverance to protect the natural beauty of the land!

The Tragic History of the Golden Rolling Hills of California

Drone pic of golden rolling hills along Interstate 5 in California (2023). Note that the road in the photograph is NOT Interstate 5, but a side road from it.

Every time I travel to California, I always marvel at the wide open vistas of the state's iconic golden rolling hills. The trip I took last month to the Golden State was no different, and as I drove along Interstate 5 between Los Angeles and Sacramento, I could not help but compare the beautiful hilly terrain with the flat and somewhat monotonous landscapes of Florida, especially after flying my drone and gazing at the land from tens of meters up.

Ground level view of the hills from an older 2005 pic. Not the same location as drone pic above.

For many Californians, the golden hued hills are just as representative of their state as the Hollywood sign in the City of Angels, or the Golden Gate Bridge in San Francisco. But most of them probably do not know the tragic history of the creation of these scenic wonders. They do not realize that these hills were not always like that.

Instead, the hills before the arrival of Europeans in the 1700s were covered in a patchwork of perennial bunchgrasses and wildflowers. Native grasses like Elymus elymoides, Nasella (Stipa) pulchra, Hordeum jubatum, and other bunchgrasses dominated the landscape. The hills were mostly green all the way until autumn due to the preponderance of perennial plants, a far cry from the golden hue suffusing them today.

Native bunchgrass species Elymus elymoides

These perennial grasses had deep roots that allowed them to withstand drought, and they formed the basis of an ecosystem that had a diverse set of forbs and other plants that provided homes and food for the native animals in the area. They were also long-lived, with some researchers saying that some specimens may have lived for hundreds of years (Marty et al, 2005).

It was into this milieu that the Europeans arrived in the late 1700s, and brought with them (whether accidentally or not) the seeds of what would initiate a major and very rapid ecological shift in the landscape. Seeds of Eurasian grass species were introduced to the continent, along with grazing animals such as sheep and cattle. 

Avena fatua along highway

Instead of being perennials, these exotic grasses were annuals, and when they senesced they turned a golden color. Within a short timespan, they had almost completely replaced the perennials. The latter were not driven to extinction,  but were instead bracketed into increasingly smaller spots by the invading species. They could not withstand the competitive abilities of the annuals, nor the new herbivores that came along with them.

One of the most notable exotics are some oat species, Avena barbata, and Avena fatua. These 2 species have beautifully drooping inflorescence, and are cosmopolitan in distribution. 

Avena fatua with empty and ripened spikelets

From a distance they are mostly a light golden color after senescenece, their bodies coating the hillsides in countless multitudes.   

Empty glumes of Avena fatua

Avena fatua

In addition to the wild oats, other species contribute to the golden hue of the hillsides. Bromus rubens is another exotic that has become a component of the hillsides.  

Bromus rubens

Another species from the genus is called Bromus diandrus, which has beautiful spikelets and is somewhat similar looking to the dreaded cheatgrass (Bromus tectorum). But in the case of this species, the spikelets are much larger and longer.

Bromus diandrus

All the above species, as well as various Hordeum spp, are now called "naturalized exotics" because over the past several hundred years they have become an integral part of the ecosystem of California. They have become so much a part of the state that most people nowadays think they are natives, and even those who find out that they were once invaders cannot repudiate and deny the nice memories they had of driving along the roads surrounded by golden hills. 

But there are newer and more damaging species that have entered into the picture just recently. 

Hordeum (?) sp

These winter annual invasive grasses are also part of the golden hillsides, and they are rapidly conquering ground against the older naturalized exotics. One of the more notorious among them is Taeniatherum caput-medusae (medusahead grass), whose silica-rich bodies allows it to smother the competition and slowly form vast monocultures.

Taeniatherum caput-medusae (medusahead grass)

Another is Aegylops triuncialis, a relative newcomer that is also becoming a big component of the golden hued hillsides.

Aegylops triuncialis

The interesting thing is that some studies have shown that the old native perennials actually can do better against these newer invasives, unlike the naturalized exotics. But unfortunately, the tragic loss of so much of the old natural grasslands has allowed medusahead grass and its ilk to spread almost unencumbered.

Drone pic of golden rolling hills along Interstate 5 (2023)

In the end, it's still ok to marvel and gawk at the beauty of California's rolling golden hills. Change is constant in biological systems, and an irrefutable part of life. Just remember that these are the products of an invasion that started hundreds of years ago, and is still going on today.

Literature Cited

Marty, J. T., S. K. Collinge, and K. J. Rice. 2005. Responses of a remnant California native bunchgrass population to grazing, burning and climatic variation. Plant Ecology 181:101112.

The Good, the Bad, and the Ugly in Vernal Pools

Alopecurus saccatus in margins of vernal pool at Jepson Prairie Reserve, CA

For a detailed look at vernal pools and the endangered species within them, click here.

The cast of characters in and around a vernal pool is quite large, but there is a certain organization to the entire panoply. In fact, it is possible to arrange the types of grasses in an idealized concentric circle, with the star of the entire show at the center (see diagram below).

At the periphery are the species that form the majority of grass cover in California. These are the naturalized exotics such as Lolium multiflorum, Avena barbata, Hordeum spp, and others. The members of this group have dominated the California landscape since their arrival during historical times, pushing the natives into isolated pockets. 

Lolium multiflorum near vernal pool in Sacramento area

Interestingly, the iconic "Golden Hills" of California are a recent phenomenon that is the result of this displacement. But whereas these naturalized exotics have free rein over most of the state, they cannot seem to overcome the vagaries of life in vernal pools. To put it simply, the seedlings drown when the pool fills up with water in the spring.

Aegilops triuncialis (barb goatgrass) near vernal pool in Sacramento area

Among these naturalized exotics are the more recent annual invasives, such as Aegilops triuncialis (barb goatgrass)  and Taeniatherum caput-medusae (medusahead grass). These winter annual grasses outcompete the naturalized exotics to form monocultures, with T. caput-medusae being one of the worst among the new invaders. These are the "baddest of the bad", to put it in colloquial terms.

Taeniatherum caput-medusae (medusahead grass) near vernal pool in Sacramento area

And if there is one species that people might point to as being the "bad AND the ugly" in the group, it would probably be medusahead grass. Masses of still-green T. caput-medusae waving in the wind are undeniably pretty, but once the grasses dry up, the long, wicked looking awns that curve in all directions is something that can only be found in the most extreme alien science fiction movies.  

Taeniatherum caput-medusae (medusahead grass) near vernal pool in Sacramento area

However, just like the naturalized exotics, all these new invasives are just as vulnerable to drowning, and they are seldom found within the vernal pool itself. Instead, I have found masses of T. caput-medusae, A. triuncialis and others such as Bromus diandrus relatively farther away from the pool margins.

The Ugly: What's that crawling up your backpack??!!! T. caput-medusae dried spikelet

Immediately closer to the center of the vernal pool are annual natives such as Alopecurus saccatus (commonly called Pacific Foxtail in the local area), a truly distinctive species that I found sporadically around Olcott Lake in Jepson Prairie Reserve. 

Alopecurus saccatus in margins of vernal pool at Jepson Prairie Reserve, CA

The margins of vernal pools can be flooded at times, and this creates anaerobic conditions in the soil. The lack of oxygen in the soil at these times kills the naturalized exotics and invasives, but some annual natives like A. saccatus have physiological adaptations that allow them to thrive beyond the reach of the usually dominant grasses.

I must admit that when I first discovered this species, I thought at first that they were Orcutt grasses. The specimens were small and compact, the flowerheads rising from the fleshy sheaths like heads poking out of bulky garments. They reminded me most of all, of toy soldiers standing at attention.

Orcuttia viscida

The deepest and most central parts of the pool are where many of the Orcutt specimens make their homes. These areas are inundated for months at a time, which is a prerequisite for this mysterious group of grasses. In addition, the presence of long term water clears the area of potential competitors.

As mentioned in a previous article, the Orcutt grasses have an array of specialized adaptations that allow them to survive the alternating wet and dry conditions of the pool. This includes a fully aquatic growth form at the beginning of its life, as well as numerous glands that produce viscid fluid to help prevent desiccation during the latter parts of its growth.

Orcuttia viscida

It is in this deeper central part that the "good" guys thrive, and it is up to us to make sure that they continue to hold on against the encroaching hordes of naturalized exotics and invasive grasses by continually working to preserve the last remaining vernal pools.

Naturalized exotic Hordeum spp. (?) close to vernal pool in Sacramento area, CA