Isoetes

• Isoetes is a genus of plants that almost make up the entire group of plants called quillworts. They are one of the most primitive groups of vascular plants that currently exist on Earth. They form a unique class of lycophytes with roughly 150 species still living today, although many species are now endangered.

• The quillworts are spore producing plants that rely heavily on water. Many species live entirely submerged while others live in seasonally flooded habitats. They do not produce flowers, fruits, seeds or wood and have only a single vein that runs through their leaves.