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Excerpts from Jim Conrad's
Naturalist Newsletter
entry dated August 13, 2022, issued from near Tequisquiapan, elevation about 1,900m (6200 ft), N20.565°, W99.890°, Querétaro state, MÉXICO
GAUDICHAUDIA CYNANCHOIDES
In an abandoned lot with thin, eroded, rocky soil overgrown with weeds and waist-high, spiny bushes, the above yellow-flowered, vine-like bush entangled itself with a spiny, young mesquite. While the flowering bush bore no tendrils, its main stems followed along the mesquite's main branches using side branches as supports. The flowering bush's side branches wound around the mesquite's branches like a vine. Without the mesquite, the bush's stems would have been too long and limber to rise above the ground.
The bush's yellow flowers displayed a very simple and basic structure -- 5 petals, 5 stamens and 5 sepals -- but the ornamentation was worth admiring. Each petal narrowed to a stem-like base, and the margins were irregularly fringed with short teeth. The stamens' filaments were flattened and closely curved inwardly over the ovary, and among the anthers some were well developed while others are reduced. Flowers seen from below showed other striking features:
Pedicels and peduncle were densely covered with white hair. However, the most distinctive feature was that each sepal bore two or only one conspicuous, egg-shaped, glands. In the field, at least in the Americas, when you see such large, paired glands on the back of sepals, you think: "Malpighia Family, Malpighiaceae."
The Malpighia Family exhibits a nearly worldwide distribution, but it's almost exclusively tropical and subtropical, with most species in the Americas. One unusual feature of the family is that its flowers have evolved not to offer nectar or pollen alone to pollinators, but oil. Our flowers' oversized sepal glands provide oil to oil bees.
The above wafer-like items are our plant's samara-type fruits. Samaras are dry, one-seeded fruits with "wings" helpful for wind dispersal. Maple and ash trees produce them, but their wings arise on one side of the fruit, while the above wings are round with the seed in the middle.
The leaf also is distinctive. It's oblong with rounded lobes at its base, and tipped with a short, hard tooth, or mucro. The margin shows no hint of teeth or indentations, and the blade surface is densely covered with white hairs. Here's a close-up of the hairs on the blade's undersurface:
Even before science figured out that the Malpighia Family's big sepal glands were oil glands and not nectaries, the family was famous for its 'malpighian hairs." Malpighian hairs are defined as hairs that lie very close to and parallel with the plant surface, but are not attached to the surface at either end of the hair. Malpighian hairs are somewhat T-shaped, but with the column of the T very, very short. In the above picture the hairs are so dense that it's hard to make out how they're connected to the leaf's surface, but if you keep looking, as in the lower, left corner, you might recognize one.
So, Malpighia Family, which embraces about 75 genera and 1300 species. In the hot tropical lowlands we encountered them frequently, but here in the dry, chilly highlands the Flora fanerogámica del Valle de México, dealing with the Valley of Mexico just to our south, documents only two genera. Of these, one produces a nutlike fruit, but ours with its round samara is the genus Gaudichaudia, of which only one species is present in the Valley, and that's GAUDICHAUDIA CYNANCHOIDES.
Gaudichaudia cynanchoides occurs from northwest Mexico south through Central America into northern South America. It bears no English name but in Mexico the literature fairly consistently calls it Hierba del Zorro, or "Fox Plant." The word hierba applies to any herbaceous plant with a green stem, not just herbs. The English "forb" is equivalent. Maybe "Fox Forb."
Gaudichaudia cynanchoides is much photographed and appears on many lists, but hardly any information at all is available about it on the Internet.
Still, this species has the honor of having been introduced to science by Humboldt and Bonpland, who passed through this very spot in 1804. Its description was published in Latin, in Nova Genera et Species Plantarum, in 1821. It was the first species known of the genus Gaudichaudia, which was named for the French botanist Charles Gaudichaud-Beaupré, botanist on a voyage of discovery around the world, from 1817 to 1820. Now the genus is regarded as represented by 58 species.