Tuctoria is a genus of three species of grass in the family Poaceae. Spiralgrass is a common name for plants in this genus. These are bunchgrass species that are found in vernal pools of central California and Baja California, Mexico. The plants are annuals that germinate under water in the spring and grow submerged for weeks. After the pools dry down, the grasses initiate a new set of foliage that lasts for one to two months until flowering and fruiting are complete.