About Isoetes echinospora Durieu
Isoetes echinospora Durieu is a species of lycophyte in the family Isoetaceae. It has several common names: spiny quillwort, spiny-spored quillwort, and spring quillwort. This species is abundant across Canada. It grows in shallow aquatic habitats, ranging from Labrador and Newfoundland west to Alaska, and south to Pennsylvania, Wisconsin, Michigan, Colorado, and California in North America. In Germany, it is only known from two locations: Feldsee and Lake Titisee, both located in the High Black Forest. This species produces 10 to 30 green to yellow leaves and a two-lobed corm. The velum covers between one quarter and three quarters of the 10 millimetre (0.39 in) long sporangium. Its round white megaspores are around 480 micrometres (0.019 in) in diameter and covered in spines. Its kidney-shaped microspores measure approximately 26 micrometres (0.0010 in) in length, and have smooth, fine spines. European populations of this species do not have the stomata that are present in North American populations. The names Isoetes muricata and Isoetes echinospora var. braunii are used for North American specimens of this species, and are often considered synonyms of Isoetes echinospora.
