Contains 4 accepted taxa overall.

Characteristics
Isoetes L.
QUILLWORT
Classification
ISOETALES
Isoetes
Citation
ISOETES Linnaeus, Sp. Pl. 1100. 1753.
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TYPE: Isoetes lacustris Linnaeus
Distribution Map Present

This species have been reported in the counties highlighted.

Species
Scientific Name Common Name Herbarium Specimens Status Photos
Isoetes appalachiana APPALACHIAN QUILLWORT Native Endangered-State OBL (NWPL) OBL (DEP)
Isoetes boomii BOOM'S QUILLWORT Native Endangered-State OBL (NWPL) OBL (DEP)
Isoetes flaccida FLORIDA QUILLWORT Native OBL (NWPL) OBL (DEP)
Isoetes hyemalis WINTERGREEN QUILLWORT Native Endangered-State OBL (NWPL) OBL (DEP)
Identification Key
1.  Megaspores of variable size, shape, and ornamentation; sterile hybrids
1.  Megaspores of uniform size, shape, and ornamentation; fertile species
2
2.  Velum covering 80-100 percent of sporangium; megaspores 250-500 um wide, with low, broad tubercles or ridges, girdle smooth; 2n=22
3
2.  Velum covering 10-30(50) percent of sporangium; megaspores 400-610 um wide, cristate to reticulate with thin ridges, girdle obscure; 2n=44 or 66
4
3.  Leaves 1.25-1.5 mm wide; megaspores ca. 500 um wide, with dense ornamentation pattern of small tubercles
3.  Leaves ca. 1.0 mm wide; megaspores 250-450 um wide, with coarse ornamentation pattern of broad tubercles or loosely interconnected vermiform mounds
4.  Megaspores (460)575-610 um wide, cristate to reticulate with thick-walled reticulate ornamentation; 2n=66
4.  megaspores 400-580 um wide, distinctly reticulate with dense pattern of tall, short-crested, almost echinate muri; 2n=44
5
5.  Leaves 1-2.5 mm wide at mid-length, dark green to bright green or dull olive-green with whitish to pale brownish green bases; megaspore ornamentation moderately to evenly reticulate with few or no stand-alone short muri or tubercles, usually with equatorial band absent or a plain band with few spines
5.  Leaves 0.5-1.5 mm wide at mid-length, blackish-green to olive green in age or upon drying; megaspore ornamentation broken-reticulate to almost spiny with numerous tubercles often with short, mostly stand-alone muri or with broken ridges, usually with an equatorial band of numerous spines
Genus Synonyms
Synonym Full Citation Basionym Type
Calamaria Calamaria Boehmer, in Ludwig, Def. Gen. Pl., ed. 3. 500. 1760. TYPE: = Isoetes Linnaeus 1753.
Cephaloceraton Cephaloceraton Gennari, Comment. Soc. Crittogam. Ital. 1: 111. 1862. TYPE: Cephaloceraton histrix (Bory) Gennari (Isoetes histrix Bory)
Isoetella Isoetella Gennari, Comment. Soc. Crittogam. Ital. 1: 114. 1862. TYPE: Isoetella duriei (Bory) Gennari (Isoetes duriei Bory