Excerpts from Jim Conrad's
Naturalist Newsletter
| from the November 6, 2011 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá
Ruins, central Yucatán, MÉXICO TEN-FT-TALL COTTON At
the right you can see me standing beside a Tree Cotton plant. You might recall that in this year's February 6th Newsletter (see next entry) we profiled a cotton plant found in Pisté producing beige, not white, cotton. That mature plant struck me as non-woody, was three or four feet tall, and its leaves were three-lobed, so I thought it was Upland Cotton of the kind much planted in the US Deep South. However, I carried seeds home with me, they germinated and I planted the seedlings right before I left the Hacienda six months ago. This woody, ten-ft-tall plant with mostly five-lobed leaves is what grew from those seedlings! And it's GOSSYPIUM BARBADENSE, known commonly as Tree Cotton or Sea-Island Cotton, not the smaller, herbaceous, three-lobed-leafed Upland Cotton. Apparently when Tree Cotton is grown in thin, dry soil, not only is it smaller, but also less woody, and its leaves reduce their number of lobes. It happens that our Tree Cotton is flowering now and a flower is shown below:
Flowers emerge as yellow but after pollination turn rose-purplish. Having many stamens in the blossom's center arising from a cylindrical "staminal tube" surrounding the style is very suggestive of a hibiscus flower. That's to be expected since both cotton and hibiscus are members of the huge Hibiscus Family, the Malvaceae. A notable feature characteristic of cotton flowers is shown in the blossom side-view below:
Cotton flowers have calyx lobes, or sepals, similar to those of many other flower kinds, but that's not what you're seeing at the base of that flower's yellowish corolla. The pale green, purple-tinged thing deeply fringed at its top (left side in photo) is a bract, which is a modified leaf. Cotton flowers are subtended by three or more large bracts that obscure the calyx lobes and the entire bottom of the corolla. The flower bracts on our Tree Cotton bear many dark glands. I'm guessing that those glands repel insects that otherwise would travel beyond the bracts and eat the flower parts, which of course the plant doesn't want. |

| from the February 6, 2011 Newsletter issued from
Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO BEIGE COTTON In an abandoned lot at the edge of Pisté I saw a leg-tall cotton plant with opening bolls releasing wads of fluffy cotton. Back in Mississippi we had lots of that at a certain time of year, but this was unlike any plant I've ever seen up there. The plant appears above. A close-up showing what was special about it is shown below:
What's unusual is that the cotton fibers aren't pure white the way cotton up North is. It's light brown, or beige, so here was something to figure out. Cotton plants belong to the genus Gossypium in the Hibiscus Family. Several Gossypium species naturally occur in both Eurasia and the Americas. Our Pisté plant is GOSSYPIUM BARBADENSE, known generally as Tree Cotton or Sea-Island Cotton. Happily, my questions about beige Mexican cotton were more than answered by a wonderful, illustrated article by James Vreeland entitled "The Revival of Colored Cotton," in a 1999 issue of Scientific American freely accessible on the Web at http://www.perunaturtex.com/scientif.htm. Pictures in that article show handsome, multihued textiles displaying a rich variety of natural cotton-fiber shades, including dark chocolate brown. Vreeland writes, "It appears that these colors were intentionally differentiated and bred by ancient Peruvian fisherfolk, who made nets and lines from the darker shades because they were less visible to fish." Our Gossypium barbadense is native to the American tropics and is much planted throughout the world's tropical areas. The Cotton Page at Wikipedia says that the first known cultivation of cotton in the Americas was here in Mexico, some 8000 years ago. (Vreeland's article claims that the earliest find dates to 2300 BCE. Presumably much older remains have been found since the article's publication in 1999.) So, I figure that our Pisté plant is nothing less than a relict of ancient cotton populations, harkening back to a time before humans began thinking that all cotton needed to be white. By the way, Fray Diego de Landa, in his 1566 Relación de las Cosas de Yucatán often mentions how the Maya, both before and after the Spaniards' arrival, slept under cotton blankets and in war wore cotton jackets as body armor. In his Chapter 49 he writes that two kinds of cotton were planted: an annual dying after its first year, surely Gossypium hirsutum and; a small tree that produced cotton for five or six years, our Gossypium barbadense, I bet. from the November 20, 2011 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá
Ruins, central Yucatán, MÉXICO
There you see a pale yellow flower and a rose-purple one arising near one another on the same branch. Corollas emerging from their buds are pale yellow and they stay yellow as the blossoms remain receptive to pollinators. Once pollinated, flowers turn rose- purple, plus they close. By turning rose-purple, the flowers become darker and less attractive to pollinators, thus helping pollinators do their work more efficiently by not continuing to attract them to flowers already pollinated. Closing the blossom accomplishes the same thing. Once a blossom has been rosy for a day or two it falls off in one piece, sometimes with an audible plop heard as I sit readying beside the bushes. from the December 4, 2011 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá
Ruins, central Yucatán, MÉXICO
The black dots are glands. I'm assuming that they issue some kind of chemical that repels potentially damaging insects. When you cut longitudinally across a developing ovary, white pulp turning into cotton fiber is seen, as shown below:
At the left in that picture four or so shiny, white, elliptical seeds are enmeshed in white pulp in which no fiber is discernable, but in the larger, more mature ovary at the right I could tease the white matrix into wet, sticky, partially formed fibers. The ovaries have to mature a good bit more before they become bolls splitting open to release soft, dry cotton. from the January 8, 2012 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá
Ruins, central Yucatán, MÉXICO
At the lower right in that picture there's an immature, green fruit, or boll, mostly enclosed in the flower's three, large, deeply incised bracts. Most bolls produce four clumps of cotton, each clump produced in an ovary's cell, or carpel, though some bolls produce only three or as many as five. Each clump contains five or less often four seeds, rarely six. Thus each boll produces on the average 4x5=20 seeds, which are the size of grape seeds, hard and dark, and difficult to separate from the cotton. The trees bear hundreds of bolls so everyone dropping by the hut nowadays is encouraged to carry seeds home and plant them. from the March 4, 2006 Newsletter issued from Hacienda
San Juan just east of Telchac Pueblo, Yucatán, MÉXICO The plant is about eight feet tall and currently is in its leafless, dry-season condition. However, new three-lobed leaves are just emerging from certain buds as the bolls are bursting with cotton. That's it at the right, with the blue-eyed dog beneath it still wandering around looking for a home |
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