JIM CONRAD'S
NATURALIST NEWSLETTER
Issued in Río Lagartos, on the northern coast of
Yucatán, MÉXICO
in Ría Lagartos Biosphere Reserve

July 12, 2015

SERRATED CASQUEHEADED BASILISK
Out at the mangroves' edge, about chest high in a Blackbead tree, something new turned up, shown at http://www.backyardnature.net/n/15/150712ba.jpg.

A closer look at the interesting bulge at the back of this lizard's head is provided at http://www.backyardnature.net/n/15/150712bb.jpg.

The helmet-like projection at the head's back told me that this was a basilisk, a kind of lizard famous for being such a fast, light runner that it can run across the surface of water. Down at Chichén Itzá basilisks were common around my hut, and I've seen them up here, too. You might enjoy browsing our page with several nice photos and stories about the Striped Basilisk, Basiliscus vittatus, the species of basilisk most common there, at http://www.backyardnature.net/mexnat/basilisk.htm.

But this basilisk is different. First, though we've documented several color variations of the Striped Basilisk, and noted how its "helmet" varies with age and sex, I'd never seen a greenish Striped Basilisk, plus a Striped Basilisk's helmet is like a vertical fin at the back of the head, not the kind of porch-like affair we see jutting from the back of the head la on this one.

So this was a new basilisk species for me, which means that it was a member of the Casqueheaded Basilisk Family, the Corytophanidae, along with the the commonly seen Striped Basilisk, but this one belonged to a different genus. We had LAEMANCTUS SERRATUS, known as the Serrated Casqueheaded Basilisk, a species endemic to this part of the world, occurring in widely separated island populations mostly in Mexico. The IUCN Red List map shows the largest population in the Yucatan Peninsula, another along the southwestern Gulf Coast mostly in Veracruz state, another population in the Central Depression of Mexico's Chiapas state, and tiny groupings here and there elsewhere in southern Mexico, plus some reports from northern Belize and Honduras.

Often such fragmented populations develop as a consequence of the population having once been much larger, but now is in retreat, leaving isolated groupings behind. Still, at least in the Yucatan, the species appears to be stable and fairly common. Serrated Casqueheaded Basilisks also are propagated through the pet trade, the species being especially popular in Europe.

Our individual perched on his bed of Blackbead leaves may be greener than usually observed because the species can change color between green and brown in a matter of minutes.

Serrated Casqueheaded Basilisks specialize in tropical dry forests. In the Yucatan, they're most abundant in the driest part, the peninsula's far northwestern corner. Like Striped Basilisks, they can run on their back legs. And I can report that as I was slowly repositioning to get a better view of the helmet, after remaining very still for a good while, it streaked into the Blackbead's branches so fast that my mind hardly registered the departure.

It eats insects, snails, small lizards and frogs.

*****

YOUNG WHISTLING DUCKS
When I arrived at Río Lagartos I was told that Black-bellied Whistling-ducks were rarely seen during the winter dry season, but as soon as the rainy season arrives they begin appearing, and the rainier it gets, the more Black-bellied Whistling-ducks we have. That seems to be exactly the case. And that surprises me because the species is considered a permanent resident here. Maybe it's a simple case of the ducks not wanting to stay around and compete with all the Blue-winged Teal and other northern duck species that overwinter here.

Whatever the case, nowadays they're commonly seen here, both on mudflats out in the estuary and in inland in marshes and saltponds. You can see two in an alga-covered pond at http://www.backyardnature.net/n/15/150712wd.jpg.

These are young ducks, as indicated by their blotchy faces. Adult faces are all gray, with a conspicuous white eye-ring. Juveniles display all-brownish heads, so these ducks' splotchy condition is a transition state from brown to gray. You can compare these with some mature ducks photographed last fall in Texas at http://www.backyardnature.net/n/14/140928wd.jpg.

*****

ROCK LICE
On the mangrove side of a culvert beneath the Malecón extending from Río Lagartos to the tourist establishment of Chiquilá east of town, there's a little pond whose banks they've stabilized by dumping large rocks at the water's edge. Algae now cover the rocks and so many crabs and other critters hide among them that when you approach the rocks there's a frenzy of scampering as things rush to shelter. One of those scamperers, with a body length minus antennae of about half an inch long (13mm) -- and there are multitudes of them -- is shown at http://www.backyardnature.net/n/15/150712rl.jpg.

That looks a lot like a pillbug or sowbug, though I haven't seen any roll into a pill. Its segmentation, seven pairs of legs, and other features make it, like pillbugs and sowbugs, an isopod, meaning that it belongs to the Order Isopoda of the Subphylum Crustacea (crustaceans) of the Phylum Arthropoda (arthropods).

We've run into something like this before, also intimately associated with water, down on the Caribbean coast north of Mahahual, where we found very similar individuals, though those were larger and bore conspicuous, antenna-like items projecting from their rear ends (uropods). You can see what they looked like and read about them at http://www.backyardnature.net/yucatan/rocklous.htm.

Back then we learned that critters looking and behaving like this are rock lice, of the isopod genus Ligia. Our rock-pile species bears speckles and spots almost identical to those we saw on the coast, despite its apparently being a different species.

Whatever kind of rock louse we have here, whenever I visit that little pond I look forward to seeing them skittering among the rocks.

*****

BARBADOS CHERRIES RIPE
Last week when my computer crashed I lost nice pictures of a shoulder-high tree that's common here in thin soil atop limestone. The trees were as loaded with bright crimson, cherry-sized fruits as up North an orchard's most prolific cherry tree can be laden with cherries. This week most of the fruits are gone, but a few aged, puckered ones still can be found on certain shrubs' gray branches, as shown at http://www.backyardnature.net/n/15/150712mp.jpg.

Several fruits, with one open to show the small, soft, whitish seeds embedded in its pulp, are shown at http://www.backyardnature.net/n/15/150712mq.jpg.

Even though now these fruits are passed their prime, they're sweet and tasty. The seeds are so small and soft that they can be chewed and swallowed.

In rainier areas farther south where the forest is much higher and lusher we've seen fruits like this on regular-sized trees, which we identified as Barbados Cherries, Malpighia glabra. You can read what we've learned about that important tree, and see its pink, Crape-Myrtle-like flowers, at http://www.backyardnature.net/yucatan/barbados.htm.

In contrast to those trees, here in our arid zone in thin soil atop limestone, our plants are little more than much-branching shrubs. Six Malpighia species are listed for the Yucatan Peninsula, so could this be one of those other five species?

I seems that our plants are the same as the tree species we've enjoyed so much farther south, just that here with less rainfall and thinner soil they make shrubs, not fair-sized trees.

While wrestling with the name situation I learned just how confused and confusing the Barbados Cherry's taxonomy is. Specifically, many experts lump together two of the six species recognized by the Yucatan's botanists, our M. glabra and M. emarginata, while others keep them separate. The Encyclopedia of Life people at EOL.Org separate them, regarding M. emarginata as the cultivated species (known commercially as the Acerola) and M. glabra as the wild one. They also say that M. glabra has smaller and more pointed leaves than M. emarginata, but I can't see much difference.

Whatever we call the species producing these excellent little fruits, they're wonderful to nibble on as you wander the marshlands as the mangroves' edge. Fruits on trees in the rainier areas farther south often are occupied by worms, but that's less of a problem in our arid area. This is a fine tree, native to southern Mexico, through Central America deep into South America, plus it's so desirable that it's grown as far north as Texas, and in subtropical parts of Asia, particularly India.

*****

A DEWY CIPURA
The highlight of each of my weeks arrives late Saturday afternoon after finishing teaching an English class, when I bike south of town and camp in the mangroves. I just need at least one night a week of quietness and solitude, for Río Lagartos, as lovely and interesting as it is, is loud, hectic and claustrophobic. In the mangroves, all you hear are birds, insects (especially mosquitoes) and wind among the trees.

Last weekend my tent was set up in an open area between mangrove thicket-groupings, or "hammocks." The spot was open because the ground consisted of flat, exposed limestone on which a little thin soil was gathered here and there, in an area sometimes flooded for extended periods. To survive in such a habitat, plants need special adaptations. Therefore, when last Sunday morning I awoke to find next to my tent a delicate, ankle-high wildflower that hadn't been flowering the evening before, I suspected that because of the difficult environment the species might be rare and maybe endemic. I could hardly wait to identify it and learn its story. You can see the little wildflower at http://www.backyardnature.net/n/15/150712ci.jpg.

First, though, I had to "do the botany" -- which was hard that morning, because of the mosquitoes.

This was obviously a monocot-type wildflower, monocots being plants such as grasses, sedges, lilies, orchids and irises, and thus often with leaves with parallel veins instead of netted ones, and floral parts in 3s, instead of 4s and 5s, or multiples thereof. Our plant's parallel-veined leaves and three larger and three smaller "tepals" (undifferentiated corolla/sepal lobes) mark it as a monocot.

Up closer, the leaves' pleated appearance and the flower's general form was more apparent, seen at http://www.backyardnature.net/n/15/150712cj.jpg.

What caught my attention here was that instead of the white corolla arising above an ovary, or having its own stem, or pedicel, it emerged from the side of one bract among several folded into a spike. Bending back a tepal to see what the sexual parts looked like, a surprisingly small and simple structure was revealed, shown at http://www.backyardnature.net/n/15/150712cl.jpg.

That looks like no more than a cluster of three stamens with banana-like, yellow anthers, atop which there's a tiny, oval, yellowish thing, which surely is the stigma atop its style, the style running down through the open zone between the three anthers. Despite the presence of the stigma and style there's no hint of an ovary, so one guesses that the ovary is hidden inside the bract from which the blossom arises.

This is just the kind of flowering structure we've seen in the Iris Family up north, with the spike-forming, overlapping green bracts forming a unit -- technically known as the "rhipidium" -- from which blossoms emerge. You may recall seeing rhipidia on your garden irises. And all this is very interesting, because usually we think of the big Iris Family as producing temperate species -- though actually the family's center of diversity is tropical Africa, particularly South Africa.

Two members of the Iris Family are listed for the Yucatan, the genera Alophia and Cipura, and when I check them out it's clear that what we have is CIPURA CAMPANULATA, without any good English name, but graced with the Spanish name Cebolla de Zopilote, meaning "Vulture Onion," which is almost painful to apply to such a pretty plant, so we'll just call it Cipura. The "onion" part of the Spanish name is apt, though, because, as with many Iris Family members, the herb emerges from an onion-like bulb.

The species is distributed from central Mexico south throughout Central America, and maybe into northern South America, so it's not endemic, and it doesn't seem particularly rare, sometimes being reported from weedy roadsides and fields.

Still, when on a chilly morning you awaken in the mangroves with dew drenching your tent and the sun just breaking through the mists, there's hardly a more agreeable companion to find next to you than a fresh little Cipura.

*****

BROOMBUSH FALSEWILLOW
At mangrove edges and out in the marshes nowadays a much-branching, spreading bush averaging about eight feet tall (2.5m) is so loaded with yellowish-white flower clusters that at a distance the whole bush seems yellowish white. Such a bush is shown at http://www.backyardnature.net/n/15/150712bc.jpg.

Up close we see that the shrub's heads are like those of the North's eupatoriums and bonesets, seen at http://www.backyardnature.net/n/15/150712bd.jpg.

With such flower clusters this is clearly a member of that subgroup of the Composite or Sunflower Family, the Asteraceae, in which the individual heads are made of packed-together disc flowers, with no petal-like ray flowers. A close-up of some heads is shown at http://www.backyardnature.net/n/15/150712be.jpg.

There you see cylindrical disc flowers projecting from pale green, urn-shaped structures called involucres, which are composed of overlapping scales called phyllaries. Notice that some of the tiny disc flowers have five, curled-back corolla lobes that barely reach beyond the involucres' tops. Others flowers project well above these shorter ones. The short disc flowers are functionally male flowers not producing fruits, while the taller ones are female flowers, some with stigmas exposed to receive pollen from other flowers. Flowering heads on some bushes hold cypsela-type fruits that are almost mature and ready to launch onto the wind with their white parachutes, as shown on the tip of my finger at http://www.backyardnature.net/n/15/150712bg.jpg.

All these details -- the plant's bushy woodiness, the flowering heads with only disc flowers, the prodigious number of flowers, the cypselae with white-hairy parachutes -- point to a well known genus, the largest of all genera of the huge Composite or Sunflower Family, the genus Baccharis, with over 500 species. Baccharis species, known generally as baccharises, occur throughout the Americas, but mostly in the tropical regions of Brazil, Argentina, Colombia, Chile and Mexico. In North America, Baccharis halimifolia, known as the Sea-myrtle or Eastern Baccharis, commonly occurs on the East Coast's and Gulf's Coastal Plain.

But our present Baccharis isn't that one, as is obvious from the leaves shown at http://www.backyardnature.net/n/15/150712bf.jpg.

For a Baccharis, those leaves are fairly unusual in that they're somewhat fleshy, bear no teeth or lobes (they're "entire,") and usually are broadest above their middles. Many Baccharis species have very narrow blades.

Our present baccharis is BACCHARIS DIOICA, found in mangroves and low spots or "hollows"between coastal dunes and hammocks -- hammocks being little islands of woody vegetation surrounded by marsh -- along Mexico's Gulf of Mexico coast, southern Florida, and the Caribbean area. The semi-succlent leaves with entire margins make it easy to identify. The Flora of North America calls it Broombush Falsewillow, the name "falsewillow" being a general term used for certain bacharises, and "broombush" alluding to the fact that it looks like certain unrelated bushes called brooms or broombushes. In other words, it's a name an editor someplace made up but Broombush Falsewillow is the best name we have in English.

Broombush Falsewillow doesn't seem to be used medicinally or as an ornamental, but I can tell you that bees and other small insects cherish its flowers' nectar, and nowadays keep the bushes buzzing with activity. Our local Maya bee keepers are grateful for their presence.

*****

MEXICAN PRIMROSE-WILLOW
In mud and shallow water at the edges of ponds, lagoons and in ditch bottoms, nowadays you find knee-high herbs with pink stems and willow-like leaves, and bearing fair-sized, brightly yellow flowers, each blossom bearing four petals, as shown at http://www.backyardnature.net/n/15/150712lg.jpg.

Up close, the flowers display a very distinctive architecture, as shown at http://www.backyardnature.net/n/15/150712lj.jpg.

There you see stamens clustered about the base of a thick style topped with an oversized, spherical stigma. Bases of the four petals -- and four is a somewhat unusual petal number -- are widely separated from one another, the stamens rising up between them. In the above picture you don't see an ovary because in this family, the Evening Primrose Family or Onagraceae, ovaries are "inferior." That means that the ovaries are located below the petals and male parts. You can see the long, reddish, stem-like ovary below our flower, with four green sepals below and between the petals, at http://www.backyardnature.net/n/15/150712li.jpg.

While I was photographing the flowers a Toltec Roadside-Skipper, Amblyscirtes tolteca, suddenly landed on one, poked its straw-like proboscis around the style and began taking nectar from nectaries between the stamen bases -- while two mating flies supped on the other side -- as seen at http://www.backyardnature.net/n/15/150712lh.jpg.

In the US often wildflowers in this wildflower's genus, the genus Ludwigia, are called seedboxes because the ovaries mature into boxy capsules filled with tiny, hard seeds, which spill out when mature. They're also called primrose willows because their leaves are so willow-like. Our plant is the Mexican Primrose-Willow, LUDWIGIA OCTOVALVIS, apparently native to the tropical Americas, but found worldwide in tropics and subtropics, including the US Deep South. With such an extensive distribution, the "Mexican" part of the common name is appropriate only from the US point of view. When you think about the plant's tiny seeds mixed in mud that's likely to stick to the feet of wandering and migrating birds, the species' worldwide distribution becomes understandable.

The online Atlas de las Plantas de la Medicina Tradicional Mexicana reports that in parts of Mexico the plant is used for various skin diseases, including mange on animals. Also a tea made of brewing the plant in hot water is diuretic -- makes you pee.

*****

BEACH SPIDERLILIES NOT ON BEACHES
In low areas on sandy beaches of the Yucatan Peninsula's Caribbean coast we've often admired Beach Spiderlilies, HYMENOCALLIS LITTORALIS, which spectacularly flower at this time of year. The species is fairly common in such coastal habitats throughout most of the tropical Americas, and because of its beauty often is planted elsewhere.

Here our Beach Spiderlilies mainly grow away from sandy beaches, in standing water or swampy mud. A typical grouping is shown at http://www.backyardnature.net/n/15/150712hy.jpg.

A closer look at a cluster of flowers atop their long stem, or scape, is shown at http://www.backyardnature.net/n/15/150712hz.jpg.

An even closer look at how the stamens' green filaments are topped with horseshoe-shaped anthers is at http://www.backyardnature.net/n/15/150712hx.jpg.

In that picture, notice how the stamens arise not from the main corolla, but rather from a funnel-shaped extension of the corolla issuing from where the corolla's petal-like lobes come together. The funnel-shaped thing is a special feature of spiderlilies, called the crown or "staminal cup." Several lily-type flowers possess crowns, maybe the most familiar being the daffodil. In our picture, the staminal cup is almost exactly one inch high (2.5cm).

Most amarylis-type plants like our Beach Spiderlily contain toxic compounds. That's the case with this species, whose juices have long been known to be antimicrobial, and thus used in various ways in traditional medicine. In particular the plant is used for skin infections, rheumatic pains, fevers and missed menstrual periods.

*****

MADAGASCAR RUBBERVINE
At a neighbor's house, two small trees out front add a touch of grace to the front yard, especially now that they bear pretty clusters of pinkish-purple flowers, as shown at http://www.backyardnature.net/n/15/150712rv.jpg.

The 2½-inch wide (65mm) flowers usually cluster in irregularly formed groups of 1-5 blossoms, as seen at http://www.backyardnature.net/n/15/150712rw.jpg.

Flowers seen from the side display corolla lobes that elegantly swirl to one side, shown at http://www.backyardnature.net/n/15/150712rx.jpg.

Those familiar with northern wildflowers will note in the above photos that this plant's leaves look like those of milkweeds, and they even arise two per stem node opposite one another, like milkweeds. Moreover, if while photographing the flowers you knock off a leaf, white, milky latex exudes from the wound, as shown at http://www.backyardnature.net/n/15/150712ry.jpg.

Milkweeds are now assigned to the Dogbane Family, the Apocynaceae, so once these details are noted the next step is to see if down in the flower's bottom the sexual parts display that family's unusual floral features. A broken-open blossom showing typical Dogbane-Family-type floral anatomy is at http://www.backyardnature.net/n/15/150712ru.jpg.

Though northern milkweed flowers don't have such large, spreading corollas, their sexual parts are very similar to what we see here. Mainly, the whitish, scale-like things in the center are pollen-producing anthers curving around and sticking to the large, flat-headed stigma beneath them. Milkweed flowers also bear "coronas" that emerge from the corolla and arc over the sexual parts. The slender, teardrop-shaped items above the whitish anthers are corona lobes and it's worth noting that the lobes gradually diminish toward their tops into a single slender, hairlike point.

Once it became clear that our plant was closely related to the milkweeds I expected its identification to be easy, for how many ornamental, milkweed-like, woody trees can there be? However, there were complications.

Mainly, our plant turned out to be the Madagascar Rubbervine, CRYPTOSTEGIA MADAGASCARIENSIS, and that "vine" in its common name was tricky. Nearly all the literature describes our plant as a woody climber or at most a scrambling shrub able to climb into trees 50ft high (15m).

Apparently my neighbor works hard to prune his plants so that they form trees. In fact, even the ones in his yard show signs of vinyness, displayed at http://www.backyardnature.net/n/15/150712rz.jpg.

Here and there such sprouts shoot out, obviously "wanting" to find a support so it can climb higher. My neighbor isn't the only one in Río Lagartos who keeps his rubbervine in tree form; people here just prefer them that way.

The plants' tree form wasn't the only identification challenge. The genus Cryptostegia embraces two very similar species, both native to Madagascar, and both widely planted and often escaped in the tropics and subtropics to become unwelcome weeds, especially in Australia. Sometimes they hybridize. Fortunately, Jens Klackenberg's 2001 "Revision of the genus Cryptostegia," published in the journal Adansonia, is freely available on the Web in PDF format at http://sciencepress.mnhn.fr/sites/default/files/articles/pdf/a2001n2a3.pdf.

In that work the most distinctive difference between the two rubbervine species appears to be that in the other species, Cryptostegia grandiflora, the slender corona lobes above the sexual parts are divided into two hair-like filaments, not remaining in one slender part like ours. Also, C. grandiflora's calyx lobes are longer than 13m, while those of our C. madagascariensis are shorter -- in ours only 9 or 10mm.

In much of the world, both rubbervine species initially were introduced not for their ornamental value but for the rubber that can be made from the plants copious white latex. The latex does produce good rubber, but at this time other sources are more economical for the manufacturing process and no efforts aret being made to grow rubbervine for that use.

The latex is toxic, however, capable of killing large livestock that eat enough of it.

*****

WANDER TIME
I'm going wandering for the rest of the month and have no idea whether I'll be able to issue Newsletters, or when the wandering will end. Who knows what's about to happen?

It feels good.

*****

FEATURED ESSAYS FROM THE PAST:

"Passing through Felipe Carrillo Puerto" from the November 6, 2011 Newsletter, at http://www.backyardnature.net/n/p/111106.htm

"Revolution Day in Pisté" from the November 27, 2011 Newsletter, at http://www.backyardnature.net/n/p/111127.htm

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at http://www.backyardnature.net/n/.