Amazon ant-plant postpones ant defenses to escape from flooding

Growing in flooding environments is a high risk strategy for plants. Izzo et al. show that in order to colonize the margins of the Juruena River, the Amazonian plant Tococa coronata (Melastomataceae) retains morphological characteristics common to juvenile plants until individuals exceed maximum flood level (MFL).

Toccata coronata
Toccata coronata. Image: Dick Culbert / Flickr

Plants growing under the MFL have smaller, thinner and more asymmetric leaves with longer internodes, and consequentially, attract high herbivory. Once above MFL, plants undergo a radical morphological change: internodes are smaller and the leaves are thicker and larger. At this point the plant can also produce domatias and host ants to defend the plant against herbivore attack. Interesting, because MFL varies with location, plants show remarkable plasticity in when they undergo these morphological changes that can vary between a few cm and 3 meters.

Further reading

Izzo, T. J., Fernandez Piedade, M. T., & Dáttilo, W. (2018). Postponing the production of ant domatia as a strategy promoting an escape from flooding in an Amazonian myrmecophyte. Annals of Botany.