Isoetes macrospora, the big-spore quillwort,[1] is a species of quillwort in the Isoetaceae family. It can be found in the deep water of low nutrient lakes in the Precambrian Shield as well as in Newfoundland, Nova Scotia, Quebec, and Ontario. In the United States, it has been found in Minnesota and south, through the Appalachian Mountains to Virginia.[2] It bears 3 to 17 long, stiff dark green leaves, sometimes with recurving tips. The sporangium can be 5 millimeters long and 4 millimeters wide, covered from one sixth to one quarter by the velum. The triangular ligule can grow up to 2 millimeters long. The spherical, white megaspores are 400 to 800 micrometers in diameter, and bear ridges that form honeycomb-like areas. The kidney-shaped microspores are 32 to 50 micrometers long, each with evenly spaced smooth papillae.[2]

Isoetes macrospora
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Lycophytes
Class: Lycopodiopsida
Order: Isoetales
Family: Isoetaceae
Genus: Isoetes
Species:
I. macrospora
Binomial name
Isoetes macrospora
Dur.
Synonyms
  • Isoetes heterospora A.A. Eat.

References edit

  1. ^ USDA, NRCS (n.d.). "Isoetes macrospora". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team. Retrieved 26 May 2015.
  2. ^ a b Cody, William; Britton, Donald (1989). Ferns and Fern Allies of Canada. Agriculture Canada.