PLANTS | ANIMALS | ECOLOGY | FUNGI | GEOLOGY | GARDENING | TOOLS
MEXICAN PLANTS & ANIMALS HOME
entry from field notes dated July 2, 2022, taken on the eastern lower slope of Cerro de la Cruz, at an elevation of ~2700m (~8850 ft), just south of the community of El Pinar, Amealco de Bonfil, Querétaro, MÉXICO, (~N20.17°, ~W100.17°)
FALSE BUCKTHORN
In a semiopen spot at the edge of the oak forest mantling Cerro de la Cruz's lower eastern slope, the above woody, slender-stemmed, much branched plant sprawled across the forest's carpet of leaves. Barely visible in the photo, it bore a few spherical, green-turning-red, 5mm-wide (1/5inch) fruits:
The leaves were shiny and stiff, most blades bearing 2-5 low teeth along their margins. The plant reminded me of wild Wintergreen of eastern North American forests. Sweet-smelling Wintergreen also is a creeping, semi-shrubby plant with shiny leaves of similar size, plus it produces small, red fruits like the above. Even the fruits of both Wintergreen and this plant hang on short, thick, down-curving stems, or pedicels. Wintergreens don't occur this far south, but Wintergreens are members of the Heath Family, the Ericaceae, and temperate, high-elevation central Mexico is home to its share of that family. Looking for more hints of our plant's identity, I cut across a fruit:
I'd meant to see how many sections, or carpels, the fruit was divided into, by cutting it across the middle. However, with my old-man eyes I couldn't see what I was doing and ended up cutting it lengthwise, from top to bottom. Still, the above picture is interesting. Instead of showing the fruit's pie-slice-like carpels, it displays longitudinal sections of two of the five carpels. The two almond-shaped items outlined in white are the coats of immature seeds, so the future seeds will be fairly large.
*UPDATE: At first, having only immature fruits, I had problems with this ID. I misidentified it as Gaultheria myrsinoides, which it very much looks like. However, Gaultheria species, I read, have very small seeds, not fairly large ones as this one indicates it'll have. Eventually the large seeds led me to the Buckthorn Family, the Rhamnaceae, and the seldom-documented species FRANGULA MICROPHYLLA, occurring only in the Mexican highlands in the Western Sierra Madres and central Mexico south into Oaxaca. Sometimes all Frangula species are called False Buckthorns because they're not in the buckthorn genus Rhamnus.
Other than having been documented here and there, there's little information about this species, though it's clear that wildlife relish the small, fleshy fruits.
Excerpts from Jim Conrad's
Naturalist Newsletter
Entry dated November 7, 2023, from notes taken at Cascadas de La Piedad waterfall 3kms NW of the community of San Pablo, municipality of Almeaco de Bonfil; bedrock of thick layers of compacted volcanic ash, or tuff; N20.1024°, W100.0019°, elevation 2360 meters (7750ft); extreme southern Querétaro state, MÉXICO
FRANGULA MICROPHYLLA
Roots of the above spindly, woody bush helped secure a dirt ledge overhanging a washout in an erosional gully in a hillside oak forest. The bush caught my attention with its red fruits, though a closer look found that mature fruits turned black:
Usually, but not always, identifying first-time encountered plants is heavily dependent on flower structure, so a flowerless bush showing no particularly unusual vegetative features can be hard to name. I hadn't even planned to photograph the bush, until a dissected fruit exposed what's seen below:
The fruit was divided into two chambers, or carpels, and each carpel contained one seed. That's somewhat of an unusual combination, which gave hope that identification would be possible.
The leaves were small with modest hints of crenulations along their margins, and arose from short petioles with slender stipules at their bases.
On leaf undersurfaces, yellowish midveins developed dark green secondary veins.
I found it hard to identify this bush. One reason was that the two seeds occupying our fruit in the photo weren't really seeds, and using technical literature for identification requires accurate use of terminology. Our "seeds" were to be considered "stones," like the stone of a peach fruit. If you crack open the hard, wrinkled surface of a peach fruit's stone, the soft, almond-like thing inside is the actual seed.
Still, after slogging through the genera and species of several possible plant families, a match for our bush was found in the Buckthorn Family, the Rhamnaceae.
In the 1996 treatment of the Rhamnaceae in the Flora del Bajío, our plant with its lack of tendrils, one exceptionally small leaf per stem node, and a fleshy fruit containing two seedlike stones, revealed itself as Rhamnus microphylla. However, nowadays that species has been shifted to the genus Frangula, so our plant is FRANGULA MICROPHYLLA.
Frangula microphylla is described as inhabiting highland forests of oak and pine. I find no mention of this species' human uses, though it's contribution to retarding further erosion in a gully would be considered useful to some. Also, its fleshy fruits surely are browsed by wildlife.