January 15, 2017
A YELLOW-FLOWERED COWFOOT
It's a pleasure to meet any new-to-you species, and take the time to notice what's special about it. Sometimes the fact that you've found something new sneaks up on you, and that's the way it was when a certain small tree began turning up heavily laden with bright, yellow flowers along the Valladolid/Rio Lagartos highway about a kilometer west of the rancho.
For, normally, any small, yellow-flowered tree or bush along the road can be assumed to be a senna, of the Bean Family. Numerous species of the genus Senna occur in the Yucatan, and it can be hard to distinguish one from the other. Knowing that now with such limited Internet time I'd probably be unable to identify any new-to-me Senna species, at first I ignored this yellow-blossomed beauty. However, gradually something about it began seeming unusual, so finally I parked the bike and went over to look closely at one. You can see one of its flowering branches at http://www.backyardnature.net/n/17/170115bh.jpg
The blossoms were a little like senna flowers, but the leaves were nothing like senna leaves. Senna leaves are pinnately compound, but look at a leaf close-up of this tree at http://www.backyardnature.net/n/17/170115bi.jpg
The flowers confirmed the plant's membership of the Bean Family, but the leaves were very unusual for that family. In fact, they're such unusual and distinct leaves that at a glance it was clear that here we had a new-to-us species of the genus Bauhinia, a group of woody shrubs and small trees known as cowfoots. You might enjoy comparing this new cowfoot to other cowfoot species commonly occurring here. There's:
Bauhinia ungulata at http://www.backyardnature.net/mexnat/bauhinia.htm and
Bauhinia divaricata at http://www.backyardnature.net/yucatan/bauhinia.htm
About 50 Bauhinia species are listed for Mexico and Central America, with five woody species occurring in the Yucatan Peninsula. Cowfoot species usually display white, pink or red flowers, so this current one with yellow blossoms was easy to identify. But, before naming it, let's look closer at its features. A flower close-up showing weakly bilateral symmetry, like senna flowers, and an unusually thick, curved style with a greenish stigma emerging from among ten stamens of unequal length is at http://www.backyardnature.net/n/17/170115bk.jpg
One of the species' most distinctive features is the calyx, which is densely covered with short, reddish-brown hairs -- they're "ferruginous" -- as seen at http://www.backyardnature.net/n/17/170115bj.jpg
The trees' legume-type fruits weren't mature yet, but an immature one containing a single seed and also covered with ferruginous hairs is shown at http://www.backyardnature.net/n/17/170115bl.jpg
Our pretty roadside tree is BAUHENIA HERRERAE. Despite its escaping my attention until now, the species is described as fairly commonly occurring from southern Mexico south to Nicaragua, with a disjunct population in Peru.
Some literature describes the tree as a creeper bearing tendrils, and a use given for the species is for binding together beams during house construction. On the ones I looked at no tendrils were noticed and the plants weren't creeping. However, they were so solidly wedged into the the roadside's dense scrub that possibly they were being held upright by their neighbors, and often you don't notice something until you know to look for it, and when I was admiring this plant I never suspected that any cowfoot could bear tendrils.
A PURPLISH PENNISETUM GRASS
I'm still finding interesting plant species introduced onto the rancho years ago, but whose identities and intended uses have been forgotten. Now they hang on as relics, sometimes just barely. That seems to be the case with a certain head-high grass plant nowadays turning up at the weedy edge of a garden, untended and losing out to more aggressive weeds. You can see it at http://www.backyardnature.net/n/17/170115st.jpg
What caught my attention was that the grass's blades were a bit purple, and the flowering heads were very dark purple, as shown at http://www.backyardnature.net/n/17/170115sv.jpg
A close-up showing that the spiky flowering head consists of many spikelets issuing from the head's axis, or rachis, with each spikelet associated with a collection of long, stiff hairs, or bristles, is at http://www.backyardnature.net/n/17/170115sw.jpg
In that picture the yellowish white, elongated items interspersed among the hairs are pollen-producing anthers.
Foxtail grasses, sometimes called bristlegrasses, genus Setaria, display such long, fuzzy, spike-like heads and are very common and conspicuous in weedy places, so at first I thought that this must be an ornamental foxtail. However, when some mature spikelets fell into my hand, they didn't look like foxtail spikelets, as can be confirmed at http://www.backyardnature.net/n/17/170115sx.jpg
For one thing, the foxtail spikelets I know are roundish or oval shaped, not long and slender like these. More importantly, when foxtail grass spikelets fall from the rachis, they leave their bristles behind. The ones in my hand clearly have taken their bristles with them. This is a big deal in grass taxonomy, so our purple plant is something else than a member of the big genus Setaria.
This grass belongs to the closely related genus Pennisetum, which doesn't seem to have any good English name for its species, so we'll just call it Pennisetum. In that genus several species have supplied purplish cultivars that can be hard to distinguish. Best I can tell, this is PENNISETUM MACROSTACHYUM var. ATROPURPUREUM. Normally the species is green, but var. atropurpureum is a purplish cultivar. The species is native to the Borneo and New Guinea are.
The species doesn't seem to have any special use, other than that it's planted in certain gardens because of its attractive, purplish appearance, to contribute to the garden's "texture and dynamic interest," as one web page states it.
During my traveling days, shortwave radio kept me informed about what was happening in the world. Nowadays, judging from what I hear here, there's not much left on the shortwave bands other than religious stations and right-wing haranguers in the US. Still, there's a little left.
For example, at 7AM, Australian Broadcasting beams news and programs to islands across the South Pacific, and a weak signal makes its way to the Yucatan. It fades in and out, and during the stormy rainy season there's too much static, but these days sometimes there's enough coming through for me to listen during the campfire breakfast.
The other day an unusually strong signal enabled me to hear most of an interview with a US researcher on human behavior. He'd just published a book on why people believe conspiracy theories. Fade-outs kept his name from me, but on Amazon.Com a recent book entitled Suspicious Minds: Why We Believe Conspiracy Theories is authored by Rob Brotherton, so maybe that's him. Whoever it was, despite the fade-outs, the following points were conveyed:
# Children less than four years old tend to assume that accidents such as tripping over tree roots are purposely caused by somebody or some thing. Adults sometimes find comfort in indulging their infantile urges -- as with thumb-sucking, crying easily, unquestionably accepting others' authority, and finding conspiracies where there are none.
# A group of people tending to believe a certain conspiracy, and another group tending to disbelieve the conspiracy, were given the same packet of information about the matter. After both groups had digested the information, those who had tended to be believers now believed in the conspiracy more strongly than before, while the disbelievers believed less. This suggests that the two groups used different thinking methods, and it might explain why having believers and unbelievers discuss the issues together seldom changes opinions.
# Conspiracy theorists provide easy-to-understand and somewhat plausible answers. More complicated, more accurate explanations may be available, but it takes less effort to accept the easily understood ones.
# Conspiracy theories may be worth considering because in the past some proved to be true -- such as Nixon being behind the Watergate break-in, and the Bush administration inventing "weapons of mass destruction" as an excuse for invading Iraq.
# Finally, conspiracy theories are fun. They draw like-minded people together, have us toying with novel and outrageous ideas, and make it easier to believe that we ourselves are not the cause of many of our problems.
Why are conspiracy theories being talked about in a naturalist newsletter?
It's because Trump's election was influenced decisively by large numbers of people believing in conspiracies, not to mention false information. Judging from his appointment to head the Environmental Protection Agency, and many of his statements, Trump's most long-term legacy will be a loss of drinkable water, a loss of breathable air, a loss of natural beauty and open spaces, a loss of once-protected species, a loss of soil good for growing food and diverse ecosystems, and a loss of that part of our public spirit which once never would have allowed this destruction to take place.
Moreover, in a sense, there's a pretty justice in all this, an elegant working out of things, as one of Nature's most fundamental laws governing us living beings properly comes into force:
If one does not prove worthy of a gift, then that gift may be withdrawn.
Best wishes to all Newsletter readers,
All previous Newsletters are archived at http://www.backyardnature.net/n/.