Contains 7 accepted taxa overall.
Characteristics
Classification
Citation
ISOETES Linnaeus, Sp. Pl. 1100. 1753.
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TYPE: Isoetes lacustris Linnaeus
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Isoetes appalachiana | Appalachian Quillwort | |||
| Isoetes engelmannii | Appalachian Quillwort | |||
| Isoetes hyemalis | Wintergreen Quillwort | |||
| Isoetes melanopoda ssp. silvatica | Eastern Blackfoot Quillwort | |||
| Isoetes piedmontana | Piedmont Quillwort | |||
| Isoetes valida | Mountain Quillwort, Carolina Quillwort | |||
| Isoetes virginica | Virginia Quillwort |
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 |
|---|---|---|---|
| No synonyms found. | |||