A Fantastic Botanical Caribbean Cruise Trip

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

We went on our first cruise in 3 years since the pandemic. Our ship landed in 4 destinations, and I spent some time botanizing close to shore. 

The locations varied in terms of the ease of botanizing and the diversity of species found.

Melinis repens in Costa Maya

COCOCAY, BAHAMAS

The first island is wholly owned by Royal Caribbean, and it is a tiny piece of land that is immaculately kept as clean as an urban park.

Most of the specimens I found were ornamental grasses that were deliberately planted, including Trypsacum dactyloides and the fountain grass Cenchrus setaceus (?) .

Trypsacum dactyloides, with male flowers (orangey anthers and filament showing) on the left and female flowers (purple stigma showing) on the right

However,  scattered along the undergrowth I found smaller specimens, such as an Axonopus sp and a single specimen that looks like a tiny Eragrostis or  Poa sp. These tiny weedy species still thrived despite the wholly artificial nature of the location.

COZUMEL, MEXICO

I walked along the Avenida Rafael E. Melgar, the coastal road that leads from the International Cruise Terminal to the downtown proper of San Miguel de Cozumel. It was a pleasant 5 km walk along a well maintained sidewalk, and I descended at times onto the beach proper, which was mostly rocky and small.

Along the way I encountered not only the usual weedy species that seemed to proliferate in all urban locations, but lawn turf grasses and the occasional coastal inhabitants like Paspalum vaginatum. This species had rigid looking leaves and robust stolons, which it used to crawl along the rocky and sandy beaches.

Paspalum vaginatum (inset inflorescence)

I also came upon a few specimens that looked remarkably like Andropogon spp on first look.

Andropogon sp (?)

Many of the larger areas had specimens of Megathyrsis maximus, which managed to rake in some sun along the edges of wooded lots next to the sidewalks.

Megathyrsus maximus spikelets (inset inflorescence), with purple stigmas and yellow-orange anthers

Quite a few areas had the turf grass Cynodon dactylus, which also showed up as escaped specimens in cracked sidewalks and parking lots.

Cynodon dactylum, with white anthers and purple stigmas

Amazingly, I also came upon many more specimens of the same tiny putative Eragrostis or  Poa sp that I had encountered once in Cococay. In one case, it had swamped the original inhabitants of a stone container along the sidewalk!

Unknown Eragrostis sp/Poa sp (?)

But by far the most exciting find I made was a species that I at first was disinclined to think was a grass. It had an inflorescence that looked nothing like the usual spikelets, but I later typed it as Paspalum fimbriatum.

Paspalum fimbriatum

The spikelets of this species had glumes and lemma that formed a fringe around the florets. Its  leaves are relatively broad,  with a slight sinuous quality in some. 

Other specimens that I encountered in Cozumel were:

Melinis repens

Dactyloctenium aegyptium

Dichanthium sp

Cenchrus spinifex (?)

Andropogon sp (?)

Sporobolus jacquemontii (which I also encounter a lot in Florida)

Eragrostis sp (?)

Eustachys sp

Eragrostis sp (?) in Cozumel, Mexico

ROATAN, HONDURAS

This stop was the least attractive in terms of surroundings.  Our ship docked in the center of the city Coxen Hole, and it was raining sporadically the entire time.

I walked east along Main St. after disembarking from the ship, although in hindsight I probably should have gone the opposite direction. 

The empty lots were filled with Megathyrsus maximus, while sprouting from the cracks in the sidewalks and other marginal places I found the usual "weedy" species, including Eustachys sp, Digitaria sp, Echinochloa crus-galli, Eleucine indica, and a single Cenchrus sandbur sp.

I returned to the ship after enduring the sporadic rains for perhaps a couple of hours, with the hope that the next landfall would yield better returns. 

Eustachys sp growing on the rocky beach at the pier 

COSTA MAYA, MEXICO

I was not disappointed, because the stop at the Puerto Costa Maya near the town of Mahahual was the most fruitful of all.

The port itself was clean and large, with the usual tourist shops. But it was the surrounding area that made the area a prime spot for botanizing grasses.

The streets were wide and clean, with resorts and large private homes interspersed with empty lots. Closer to the Port, the wide street (Avenida P del Puerto) did not have sidewalks along the sides, but it instead had a very wide island that was filled with trees and plants. Amazingly enough, a dirt path run through the center of the island, so pedestrians using this "sidewalk" seemed to be in some forest path! It was a rather innovative idea, and one that I had never encountered before.

Path between stands of vegetation in the street island of(Avenida P del Puerto)! A great concept for urban and suburban roads

It goes without saying that I felt safe wandering into the smaller side streets, and just a few blocks from the port I came upon an empty lot that was filled with all sorts of species. 

Field of Botanizing Dreams. Eustachys sp and Dichantium sp in foreground, pinkish Melinis repens in background.

It was a literal field of botanizing delights, with waving masses of Eustachys sp mingling with clusters of pink and red Melinis repens. 

Melinis repens

Other inhabitants included the ubiquitous Dactylocnium aegyptium, Dichantium sp, as well as Cenchrus sp and an unknown species that was probably a Paspalum. There was even a large Megathyrsus maximus to one side.

Eustachys sp (left) and Dichantium sp (right)

Beyond the field I continued in the general direction of Mahuhual Beach, and I continued to encounter interesting specimens.

Once in awhile I came upon individual plants that I typed as Andropogon (perhaps A. virginicus because of a sheath that partly covers the spikelets) , which surprised me, as I always associated that clade with North America, and not tropical regions.

Andropogon sp (?), habit and spikelets

I also found an attractive broad leaved grass that I identified as Paspalum mandiocanum. The leaves had minute dark sinuous curves along their edges, and I found specimens along the sides of one of the main thoroughfares (Carretera A Mahahual).

Paspalum mandiocanum

Even the crabgrasses caught my attention. One specimen had a beautiful sinuously striped rachis and ciliated spikelets, and I typed it as Digitaria ciliaris.

Digitaria ciliaris

I also encountered specimens that I could not type, including a tallish and elegantly slim grass that had alternating green and white appearance to its culms (due to the leaf sheaths staying close to the culm). I typed it to perhaps Hyparrhenia rufa.

Unknown species (Hyparrhenia rufa?)

All in all, it was a great day for botanizing, and a great end to my December Caribbean Cruising trip!

Volcanos, Carabaos, and Misidentifications - More Botanizing in Cavite, Philippines

Carabao are these huge bovine grazers that are much cooler than cows and are a fixture of tropical Southeast Asia. 

They are used in harness to help plow the soil for farming, and their milk is for drinks and eating. When curdled the milk becomes a delicious soft white cheese called kesong putih. You can even pour the milk onto white rice, sprinkle some salt, and dig into the yummy dish (it's one of my favs).

Modern water buffalo (Da - Own work, CC BY 2.5)

One of the grasses in the Philippines is called Carabao grass (Paspalum conjugatum), due mainly to the fact Carabaos (although not cattle) seem to love this species.

Habit of A. compressus

On a second (shorter) botanizing expedition into the semi urban wilderness of the town I stayed in, I encountered a small cluster of grass that I at first thought was this species.

The dark green leaves had an interesting crinkly quality to them that reminded me of Oplismenus undulatifolius, and the specimens crawled around on robust stolons that allowed it to monopolize the shaded area under a tree.

Each hairy node produced a new ramet, along with short fibrous roots.

Stoloniferous growth in A. compressus

I typed it first as Paspalum conjugatum (carabao grass), but after some research decided that it was Axonopus compressus. The dark green leaves and penchant for shade pointed to this species, and the inflorescence nailed it.  

Attractive crinkly leaf of A. compressus

This is another species used as turf grass in the local area, but it is also used as a cover crop under oil palms, where it suppresses weeds using allelopathic chemicals (Samedani et al, 2013).. 

Inflorescence of A. compressus

Misidentifying grass species like I initially did with A. compressus above is likely not that unusual, and it seems I also did it for one of the more common and large grasses in the country

Awhile back I posted about the Destructive Duo of Imperata cylindrica and Saccharum spontaneum. The photos in that post were from the periphery of Taal Volcano in the Philippines, and I had described the taller species in them as S. spontaneum, which is called talahib here.. 

I had a chance to visit the area in Tagaytay last week, and I again encountered the same very tall species, along with the shorter I. cylindrica. This time I toured a national tourist attraction called the People's Park in the Sky, which dates from the dictator Marcos era and was supposed to have become a mansion at the time.

Erianthus (?) flowerheads with Taal Lake and Volcano in background

The tall grass was just as majestic as before, their flowerheads hanging high above the crowds, and the species covering a large part of the hillside. I flew my drone to take pics, and you can see me in the orange cap as I positioned the DJI Mini 2.

Red showing large masses of Erianthus (?) along hillside

The arrangement of the rather stiff leaves reminded me of Phragmites australis or Arundo donax, although the very prominent white midrib reminded me of other Saccharum spp.

Inflorescence and leaves (with white midribs) of Erianthus (?)

As always when I encounter an unknown species, I took macro photos of some dried spikelets, and I was surprised to discover that the large grasses were definitely not S. spontaneum!

Spikelets of Erianthus (?)

The dried spikelets had very long and twisted awns, which is not characteristic of awns from S. spontaneum. The awns are instead a characteristic of Erianthus contortus and E. alopecuroides, although this is likely another species entirely.

Spikelet of Erianthus (?), showing twisting awn and white hairs at base

Finally, I also came upon some specimens of what I believe is Echinochloa crus-galli. This species is commonly known here as bayokibok (Tagalog), lagtom (Bikol), marapagay (Ilokano), as well as some other common names probably.

Echinochloa crus-galli inflorescence

Like some other weedy grasses, I encountered this species as well in New Jersey, so you can tell that it is a really adaptable organism. In the Philippines, it is one of the worst weeds in rice paddies, and has become resistant to the herbicides used against it.

Echinochloa crus-galli spikelets

After 2 weeks, my time in the Philippines had come to an end, and although it was short and busy, I was gratified that I was able to spend some time botanizing in the hot and humid tropical clime. I love exploring new and interesting places, and discovering, identifying, and learning about the various species that I encounter in my travels.

Literature Cited

B. Samedani, A. S. Juraimi, M. Y. Rafii, A. R. Anuar, S. A. Sheikh Awadz, M. P. Anwar, "Allelopathic Effects of Litter Axonopus compressus against Two Weedy Species and Its Persistence in Soil", The Scientific World Journal, vol. 2013, Article ID 695404, 8 pages, 2013. https://doi.org/10.1155/2013/695404

Weed of the Month: Echinochloa crus-galli (barnyard grass)

Echinochloa crus-galli (barnyard grass) spikelets with purple stigma

Echinochloa crus-galli is commonly known as cockspur (or cockspur grass), barnyard millet, Japanese millet, water grass, common barnyard grass, or simply "barnyard grass".

Echinochloa crus-galli (barnyard grass) with yellowish anthers

This species is considered one of the world's worst weeds, because it reduces crop yields and causes forage crops to fail by removing up to 80% of the available soil nitrogen.

Echinochloa crus-galli (barnyard grass), no ligules

It is an invasive weed in all the states in the continental USA, and is particularly adapted to wet areas such as paddy fields

I found it growing from the side of a stand of Imperata cylindrica (Japanese Blood Grass).

Specimen of this cosmopolitan grass from the Philippines

I identified it from the absent ligule and the distinctive inflorescence, including the fact all the spikelets were crowded on only one side of the central axis.

Echinochloa crus-galli (barnyard grass), with purplish base