CPC Plant Profile: Spike Quillwort
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Spike Quillwort (Isoetes prototypus)

Donald Cameron © 2018 Photo Credit: Donald Cameron © 2018
  • Global Rank: G2 - Imperiled
  • Legal Status: N/A
  • Family: Isoetaceae
  • State: ME, NB, NS
  • Nature Serve ID: 146303
  • Date Inducted in National Collection: 12/07/2021

Isoetes prototypus, Prototype Quillwort, is an aquatic, perennial graminoid. It grows fully submerged in cool lakes at water depths of at least 5 feet. Like many Isoetes, it grows as a clump of long (up to about 4.5 inches), narrow leaves. It produces spores, not seeds, from a structure called a sporangium that grows at the base of the clump. It is distinguished from I. acadiensis by the tissue that covers the sporangium. In I. prototypus this tissue covers the entire sporangium, but the sporangia of I. acadiensis are only partially covered. (Brunton and Britton 1993; Environment Canada, 2012; New England Wildflower Society, 2018; USDA and NRCS, 2018) Isoetes prototypus has an extremely restricted range. It is known from only 20 lakes; 5 in Maine and 15 in Canada. However, as of 2016, the global population was estimated at about 250,000 individuals, and that number is thought to be stable. Therefore, its global conversation assessments vary. It is assessed as Near Threatened by the IUCN Red List process, but as Imperiled (G2) by the NatureServe G-Rank process. In Canada, where most of the global population exists, its federal status is Special Concern. (Environment Canada, 2012; NatureServe, 2017; Smith 2016)

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Taxon Isoetes prototypus
Authority D.M. Britton
Family Isoetaceae
CPC Number 44907
ITIS 503215
Common Names Prototype Quillwort | Spike Quillwort
Associated Scientific Names Isoetes prototypus
State Rank
State State Rank
Maine S1
New Brunswick S2
Nova Scotia S2

Ecological Relationships

Common Name Name in Text Association Type Source InteractionID

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