Wednesday, November 30, 2022

Bamboo, Bamboo Look-Alikes, and a 'Miracle' Grass at the Harry P. Leu Botanical Garden

Bambusa vulgaris 'Vittata' (Striped Timber Bamboo)

Bamboos form the subfamily Bambusoideae, and there is no doubt that they are some of the most beautiful grasses around. Their colorful culms, delicate leaves, and the majestic heights reached by some bamboo species, make them a favorite of many plant collectors and  growers, and their economic importance as structural materials is second to none in the Poaceae. In addition, bamboos hold a special place in the cultures of many East Asian countries.

Bambusa malingensis (?) dwarfs passersby

I visited the Harry P. Leu Botanical Garden in Orlando, FL and spent some time marveling over these plants, but also discovered a few other new grasses that I had never encountered before.

As always, the bamboos were probably one of the highlights for many of the people visiting the garden.  People were especially enthralled by the larger specimens, which towered over them and rose to reach the heights of the surrounding trees. Unfortunately, even though there were signs that urged people not to do so, I saw instances of culms with the initials of visitors carved into them. 

Bambusa vulgaris

There is a common misconception that the bamboos are the most "primitive" of the grasses (probably due to the fact some are woody), but recent studies show that the Bambusoideae diverged after the rice subfamily (Oryzoideae), and much later than the three earliest grass subfamilies (Anomochlooideae, Pharoideae, and Puelioideae). More on grass phylogeny in some future post, I promise.

Although many of the specimens I found were varieties of Bambusa vulgaris (Timber Bamboo), there were quite a few other species that caught my eye. 

A medium sized bamboo (Dendrocalamus minor 'Amoenus') that had a bluish tint to its culms entranced me.

Dendrocalamus minor 'Amoenus'

I was also interested in a smallish bamboo with the funny name of Pseudosasa japonica 'Tsutsumiana' that was hidden among its towering brethren. Its form and attractive foliage made me think it would make a nice houseplant, if only it stopped growing at a manageable height! But the highlight of my trip turned out to be some of the non-Bamboo grasses.

Pseudosasa japonica 'Tsutsumiana'

A few of the species that were also in the bamboo section of the park looked remarkably like small bamboo, but were in fact not in the subfamily Bambusoideae at all! 

Thysanolaena latifolia

Thysanolaena latifolia (called Tiger Grass in some places, and Broom Grass in others) had elegant broad leaves, and I thought at first it was another bamboo. The specimen I found in the shade sported dried flowerheads that looked like brooms, and in their native habitat they are in fact used for sweeping.

Thysanolaena latifolia seedheads

Another grass that really caught my attention was a small cutie that only reached to my calf called Pogonatherum paniceum. It looked like a bamboo as well, and it had gorgeous striped leaves and an attractive roundish habit. It is used as an ornamental in some places, and I have a feeling I might get one for my garden someday.

Pogonatherum paniceum

One other specimen that held my attention showed up near the end of my visit. The day was coming to a close, and I was hurrying towards the exit when I came upon an entire section that was dedicated to ornamental, and other, grasses.

In addition to the usual ornamental grass suspects like Miscanthus spp, as well as economically important species like Saccharum officinarum (Sugarcane), the lot had a species that I had been hearing about a lot in my sojourns on facebook, but which I had never seen in person.

Chrysopogon zizanioides (Vetiver grass) habit

Chrysopogon zizanioides, which is also called Vetiver grass, is a species which has its own groups in Facebook, and its many economic benefits has been been touted loudly and repeatedly by its many boosters around the world.

Chrysopogon zizanioides (Vetiver grass) seedheads

C. zizanioides is considered part of a low cost technology solution that has helped to solve various problems. It has a massive root system that grows vertically and deep into the soil, which makes it ideal for erosion control. These same roots also spread and slow down runoff so it passes harmlessly across farmland, and the ability of the grass to tolerate very high levels of heavy metals makes it ideal for soil remediation. It is also used for pest control in that it is attractive to many insect pests (e.g. stem borer moths), which lay their eggs on the plants instead of nearby crops. The larvae who feast on C. zizanioides die due to chemicals in the grass that interfere with their digestive system.

It really is  a so-called 'Miracle' Grass to the many people around the world who have used it! 

Here are some of the species that I discovered and mapped by GPS in the Harry P. Leu Botanical Gardens:


Bambusa dissimulator
Bambusa eutuldoides 'Viridivittata'
Bambusa malingensis
Bambusa multiplex
Bambusa multiplex 'Golden Goddess'
Bambusa oldhamii
Bambusa textilis var gracilis
Bambusa vulgaris
Bambusa vulgaris 'Vittata' 
Dendrocalamus asper
Dendrocalamus minor 'Amoenus'
Otatea fimbriata
Pseudosasa japonica 'Tsutsumiana'

In addition to the bamboos, I was happy to find some Other Grasses:

Arundo formosana
Chrysopogon zizanioides
Miscanthus spp
Pogonatherum paniceum
Thysanolaena latifolia
Saccharum officinarum
Trypsacum spp

...and a few more that I had no time to survey due to the park closing.

For visitors to the park later, I created a google map of the specimens that I found. You can find it here:

Monday, November 21, 2022

Letting Your Lawn Grasses Flower

Stenotaphrum secundatum (St. Augustine Grass) flowerhead with orange anthers and purple stigmas

Notwithstanding the growing complaints about lawns, a lawn of turf grass has some aesthetic  qualities. Lawns are clean looking to some people, and they project a sense of ordered structure that a mélange of different plants squeezed together might not.

Paspalum notatum (Bahiagrass) with purple anthers and stigmas

But aside from a few weedy species like Poa annua that thwart the mower's blades by flowering close to the ground, the various turf grass species are kept from showing their full reproductive selves by the regular mowing that homeowners do. This incessant desire to keep the lawn grasses short prevents the grasses from pushing up flowerheads and scattering pollen and seeds to the winds, while making it difficult for homeowners to identify the grass from just their vegetative structures.

Zoysia matrella with tiny spikelike flowerheads

Most turf grasses have relatively tiny inflorescences, a consequence of the fact grasses are wind-pollinated and have no need to expend energy on unneeded colorful petals and sepals. In addition, turf grasses are usually species which have evolved to be grazed, so they eschew tall stalks and flowerheads and keep close to the ground. 

But it is still fascinating to see the usually colorful stigmas and anthers via some magnification, and by setting aside parts of the lawn as temporary no-mower areas, owners can finally see the turf grasses flower, as well as type them more accurately to species.

Eremochloa ophiuroides (centipede grass) with silvery stigmas and purple anthers

So take some time to see what the flowers of your own lawn looks like. Make at least some part of your lawn no-mow until the tiny flowerheads and seedheads rise up to scatter your lawn's grass seeds to the wind.

Friday, November 11, 2022

Stepping into Prairie Grasses: An Introduction & Primer

Schizachyrium scoparium (little bluestem) inflorescence

The Missouri Prairie Foundation was kind enough to invite me to write an article introducing people to the prairie grasses. I am not an expert, but I spent some time making diagrams of grass structure and macrophotographs of  some of the major tallgrass prairie species.

You can read it here (a PDF file, starting on page 14). Enjoy!


Saturday, November 5, 2022

The Armored Spikelets of Sandburs and Sandspurs (and how one became a part of me)

Burs/Spikelets of Cenchrus echinatus

One of my favorite group of grasses are the so-called sandburs or sandspurs.

These are species in the genus Cenchrus, and they sport spikelets ensconced in armored, thorned burs. There are usually several spikelets nestled within the shell.

A single inflorescence of C. echinatus 

I find the resulting structures (which are sometimes vividly colored) attractive in a dark and deadly way; botanical weaponry that is achingly beautiful in its form and function.

But the main function of the burs is actually more mundane, as they are principally used to disperse the seeds of the plant via animal hosts. The thorns frequently catch onto the skin or clothing of some passing host, and the entire bur is then carried far away from its original location. There have also been studies that show the bur floats and aids in dispersal via water.

Less mature burs/spikelets of C.echinatus

I encountered sandburs in NJ, and also in the Philippines. In both cases, the species was not in abundance in the area, but the small stature of the grass (and its annual nature) might cause one to underestimate their prevalence.

I finally came upon a sandbur species here in Florida while walking between homes that were under construction. The plants were in a sunny location in what would be the front lawn in the completed home.

I typed it as Cenchrus echinatus (which is called Southern Sandbur in some places here), based on the globular, pubescent bur, which has upper (inner) spines fused at the lower part and a ring of bristlelike lower (outer spines) near the base.

In my eagerness to take photographs of the cluster I accidentally brushed against one of the seedheads and a bur stuck to my right middle finger. I absently brushed it off, and was annoyed to discover the spine had broken off and was still lodged in my skin. 

When I got home and my wife and I tried to remove it, we found out that the spine had penetrated deeper than we thought, and it was impossible to dig it out without creating a deeper wound. When I visited a doctor later, she could not make it out (and I did not feel it when she applied pressure on the area), so she decided to leave it in and said that the small piece would be pushed out by my body as it repaired the wound.

And so now, not only am I made mostly from grass because of the food that I eat, but I probably have weaponry from a grass forever lodged under my skin. I truly am becoming an Orang Poaceae!