English: Lake quillwort; Merlin's grass.
Synonym: Isoetes hieroglyphica.
Region: Europe, Poland to northeastern France, Scandinavia, British Isles, Faroe Islands, Iceland,Bulgaria; North America, Maine, Vermont, New Hampshire, Rhode Island, Massachusetts; Canada, New Brunswick, Nova Scotia.
Habitat: cold climates; stony or sandy bottoms of clear, usually slightly acidic ponds; in mountain tarns; at 5 to 460 cm depth of water.
Use: aquarium plant; educational resource.
BotanyFern; perennial.
Leaves: many; long, narrow, 8 to 20 cm long and 0.5 to 2 mm broad, to 5 mm at the base; a sac at the bottom of each leaf base produces the spores.
Stem: very short, called a corm, where all the leaves and roots are attached close together.
Root: not traditional, some leaves are modified into pseudo-roots are called rhizomorphs. They are attached to the bottom end of corm. The upper leaves are green, sprouting in a clump.
Reproduction: late summer or early fall.
Spores: 2 types, female are megaspores, about 0.5 mm diameter; male spores are microspores, a few micrometres in diameter.