Excerpts from Jim Conrad's
Naturalist Newsletter

from the November 14, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO; limestone bedrock, elevation ~39m (~128ft), ~N18.52°, ~W95.15°
BLADDER MALLOW

Bladder Mallow, HERISSANTIA CRISPA

Above you see a yellow-flowered weed with green, ribbed, inflated, Chinese-lantern-like fruits next to my hut door two weeks ago. I've delayed introducing the little plant because it's taken me two weeks of hard internetting to identify it. At first glance it looks like any number of weedy, yellow-flowered herbs blossoming these days, but a closer look reveals lots of curious features, especially those Chinese-lantern fruits.

Obviously it's a member of the Hibiscus Family, the Malvaceae, because of how the many stamens join at the bases of their filaments into a cylinder around the ovary's style. Two views of a flower are shown -- the view on the left showing the tree-like collection of stamens on their "staminal column" overtopped by ±7 filament divisions topped by blunt stigmas -- below:

Bladder Mallow, HERISSANTIA CRISPA, flower

A 2/3-inch-wide (17 mm) fruit pod -- the view at the left showing a head with its nine hairy segments intact while the view at the right shows the segments open, exposing the seeds -- is shown below:

Bladder Mallow, HERISSANTIA CRISPA, fruiting head

You can see what the segments look like when they open and fall from the head below:

Bladder Mallow, HERISSANTIA CRISPA, seeds with wings

Those open segments clarify why the plant goes to all the trouble of making those Chinese-lantern heads: Each segment ends up equipped with two wings capable of catching the wind and carrying the seeds downwind.

The plant finally has revealed itself to be what's sometimes called Bladder Mallow in English. It's HERISSANTIA CRISPA, Herissantia being a genus I'd never even heard of.

In fact, this whole two-week exercise in identifying this plant has mightily impressed me with regard to the size and diversity of the Hibiscus Family, which in its traditional sense embraces over 200 genera and about 2300 species. Recent genetic studies have caused most experts to lump several families formerly regarded as distinct into the Hibiscus Family, including the Basswood, Sterculia and the Bombax Families, which makes the family even much larger.


Entry dated January 29, 2024, issued from near Tequisquiapan; bedrock of compacted volcanic ash, or tuff; elevation about 1,900m, (6200 ft), ~N20.57°, ~W99.89°; Querétaro state, MÉXICO
BLADDER MALLOW, WHITE FLOWERS

Bladder Mallow, HERISSANTIA CRISPA, habitat

Along a dirt street at the edge of a village, the above plant was conspicuous because during this dry-season period of a continuing two-year-long dry period characterized by the North American Drought Monitor as a D3 Severe Drought, it was one of very few plants managing to flower. It's worth knowing any plant tough enough to prosper under such conditions, for they're poised to become more important during global warming changes. I'd been watching this plant for about two weeks, for it always kept its flowers somewhat closed as, shown below:

Bladder Mallow, HERISSANTIA CRISPA, white flowers somewhat closed

Apparently, the plant didn't plan to open its flowers unless it rained, maybe because of its drought adaptations. At first I didn't recognize this as a Bladder Mallow because I'm accustomed to yellow blossoms on that species. On the Internet, images of the flower display colors ranging from deep yellow to white. Above, note the petals' yellow bases between the sepals. I think the yellow splotches at the top are pollen daubed there by holding the petals close to the ripe stamens.

Bladder Mallow, HERISSANTIA CRISPA, hairy schizocarp

The schizocarp-type fruits were like those seen in the Yucatan, though they were smaller than I remember, and with fewer divisions, or mericarps; possibly this is another drought adaptation. Leaves were similarly hairy and shaped, though smaller:

Bladder Mallow, HERISSANTIA CRISPA, leaf from above

With regard to this tough species' adaptations, the plant pictured above in this section shows a growth pattern keeping close to the ground, while those in the Yucatan usually stood erect. Also, notice how the plant's branches radiate from a base in our picture's top, right corner, where most stems have been cropped by roving flocks of sheep. The ground-hugging stems provide yet another adaptation for areas grossly overgrazed by livestock.

Moreover, the soil our plant grows in is rocky, hard-compacted, and very eroded with low organic matter content. This may be its main adaptation for a planet more and more becoming like our parched, profoundly abused landscape here.