The Atala and Coontie—a Comeback Saves Two Species

Friday, September 27, 2013

While taking a quick walk outside the Gallery building this morning I spotted a red caterpillar against the olivey-green leaves of a coontie (Zamia integrifolia). Then another, and another. It had to be the larvae of the atala butterfly (Eumaeus atala), which is infamous for depending on the coontie as its host plant. On close inspection, they are more like a brilliant glossy magenta scarlet, more orange towards their undersides, with two rows of seven yellows spots along their backs. During the 19th and early 20th centuries, coontie roots were ground up for food; processed and washed to remove their toxins, which are known to be carcinogenic, among other nasty qualities.

Atala larva on coontie
An atala (Eumaeus atala) butterfly larva feeding on
a coontie leaflet.

The resulting starch had been used for flour for centuries by southeastern Native Americans, and later with almost devastating efficiency by Florida pioneers. The starch is sometimes called arrowroot, but that name may apply to starches derived from quite a few different plant sources. Arrowroot biscuits were very popular in Victorian times, and the name can still be found on some products. The USDA banned arrowroot production—as derived from coonties—in 1925.

Circa 1890 coontie mill
A circa 1890 coontie processing mill.

With the ban on coontie arrowroot, and the demand for arrowroot being supplanted by other starches, the coontie plant dodged the bullet of extinction, along with the atala butterfly. In fact the atala was thought extinct (a Lazarus taxon) for decades. Its larvae, aka caterpillars, feed exclusively on coonties and a few other similar cycads. No coonties, no atalas. Thankfully, the coontie and atala seem to have rebounded.

Coonties are found in multiple locations throughout the Garden, but the examples hosting atala larvae that I encountered are in Plot 123a, near to Cycad Circle.

Atala pupa in chrysalis
Atala pupae within chrysalises
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