Zamia integrifolia (Zamiaceae)
Origin: Florida and Georgia, Cuba, Bahamas?
We have featured plants before which do not bloom, most of them spore-releasing ferns. Our featured Florida native this month, coontie, is a cycad, which like ferns is a group of ancient plants predating the dinosaurs. Since cycads go back so far in evolutionary history, they also have “simple” reproductive strategies compared to plants which bloom, and are classed in the category of “cone-bearing” plants, much like pines. Like most pines, cycads have male and female cones. Unlike most pines, however, which have male and female cones on the same tree, cycads are dioecious, meaning that the plants themselves are either male or female. The male cones are long and thin, and at maturity crack open slightly to reveal and offer the chunky pollen. The female cones are short and stout in comparison, and when receptive also crack open slightly to allow access to the interior of the cone. Most cycads are pollinated by those ancient insects the beetles, and our native Zamia is no exception. The receptive female cone allows access to its insides to beetles and the pollen they carry with them from male cones visited earlier. Once fertilized, the female cone remains attached to the plant for the remainder of the season, swelling up and eventually spilling its orange-red fleshy seeds. This flesh contains germination-inhibiting chemicals, and must be removed for the plant to propagate. This is achieved by birds, particularly jays, as well as some small mammals. The plant is also a larval host for the rare atala butterfly.
Not only is coontie a source of food for Florida’s animal population, but for its historic human populations, as well. The Seminoles and others living in the state before industrialization made a type of bread out of the caudex of the plant, which is rich in starch. The root is also rich in cycasin, which is a potent toxin, and needs to be processed properly (a technique involving grating and soaking) in order to be consumed safely. Young industry in Florida, which involved tapping pine trees for their turpentine, raising cattle in the flatwoods, and digging phosphate pits by hand and mule team, saw this source of starch as a novel opportunity to make money, and by World War I there were several plants in Florida processing coontie for their starch, known as “Florida Arrowroot,” with one such plant processing 15 to 20 tons of the slow-growing plants per day for a military contract. Zamia integrifolia, which used to be found growing in various habitats all over the state, is now a pretty rare sight in the wild, and protected from any collection. The atala butterfly, which depends on the plant for its survival, is a rare sight as well, although the surge in popularity of coontie as a landscaping plant is apparently helping to change that trend.
Coontie makes a great low-growing hedge or groundcover, and also can add interest to a garden as a single specimen, especially a female in cone. The fronds are very susceptible to damage by scale insects and mealy bugs, especially when plants are close together creating a crowded thicket of fronds. Mature plants actually benefit from an occasional defoliation, which not only gets rid of the insect population but also provides air flow to the interior and crowns, helping to prevent future insect infestations. The fronds, which grow less than a meter in length, are the only part of the plant to protrude from the ground; mature plants tend to form a small mound. The caudex, which is the part of the plant used for food and starch production, is a subterranean energy storage system for the rest of the plant, and allows it to come back so effectively from defoliation by cold, herbivory, fire, or pruning sheers. Here at Selby Gardens we have many examples of Zamia integrifolia planted on our grounds, including our numerous native gardens.
Text by David Troxell