Martine, a biodiversity scientist at Bucknell University in Pennsylvania, has been studying nightshades in the Australian Monsoon Tropics for 20 years. Even so, he struggled to make sense of these particular specimens, which seemed to display a different sex every time researchers took a look. As you may remember from middle school biology class, most (but not all) flowering plants are bisexual, meaning they have flowers with both pistils, which produce female gametes, and stamens, which produce male gametes. Some species, like squash, have distinct male and female flowers. And still other species, like cannabis or holly, have only one sex, with distinct male and female plants. But, as Martine describes in a new report, published Tuesday in the open-access journal PhytoKeys, a single bush tomato can appear as strictly male; hermaphroditic, with both male and female sex characteristics in its blossoms; or it can even carry single-sex and hermaphroditic flowers simultaneously. Individual plants seem to go through phases of presenting different sexual structures. That's why the authors named it Solanum plastisexum, or malleable sex.