Isoetes echinospora

Isoetes echinospora, also known as spiny quillwort,[1] spiny-spored quillwort[2] or spring quillwort[3] is a species of quillwort in the Isoetaceae family, and is the most abundant species in Canada.[4] It can be found in shallow aquatic environments from Labrador and Newfoundland to Alaska, and south to Pennsylvania, Wisconsin, Michigan, Colorado, and California. In Germany it is found in only two locations: the Feldsee and Lake Titisee, both in the High Black Forest.[5]

Isoetes echinospora
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Lycophytes
Class:	Lycopodiopsida
Order:	Isoetales
Family:	Isoetaceae
Genus:	Isoetes
Species:	I. echinospora
Binomial name
Isoetes echinospora Durieu
Synonyms
Isoetes echinospora var. braunii Engelm. Isoetes muricata Durieu

It bears 10–30 green to yellow leaves and a two-lobed corm. The velum covers one to three quarters of the sporangium, which are 10 millimetres (0.39 in) long. Round white megaspores are about 480 micrometres (0.019 in) in diameter and are covered with spines. Kidney-shaped microspores are about 26 micrometres (0.0010 in) long with smooth, fine spines.[4] European populations of the plant lack the stomata present in North American populations.

Isoetes muricata and Isoetes echinospora var. braunii refer to the North American plants, but are often considered synonyms of Europe's I. exhinospora.[2]