Jepson eFlora: Taxon page
Vascular Plants of California
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Isoetes nuttallii

Higher Taxonomy
Family: IsoetaceaeView Description 
Habit: Perennial herb, aquatic to terrestrial. Stem: buried, corm-like, 2--3-lobed, corky, brown. Leaf: simple, in grass-like tufts, spirally arranged on stem top, erect to spreading, < 30 cm, linear above base. Sporangia: solitary, embedded in wide leaf base, < 1 cm, +- covered by a translucent membrane, male or female; male spores > 10000, < 0.045 mm, +- bean-shaped, gray or brown in mass; female spores 20--200, 0.2--0.7 mm, spheric, white, +- smooth, ridged, tubercled, or prickly.
Genera In Family: 1 genus, 200+ species: worldwide.
eFlora Treatment Author: W. Carl Taylor & Jon E. Keeley
Scientific Editor: Alan R. Smith, Thomas J. Rosatti.
Genus: IsoetesView DescriptionDichotomous Key

Common Name: QUILLWORT

Etymology: (Greek: evergreen, from habit of some species) Note: Perhaps most poorly known lycophyte genus. Mature female spores, found in decaying leaf bases or soil, critical for identification, as are hand lens for texture when dry, microscope with micrometer for size. Hybrids (spores of variable size, shape) common between aquatic species, making them less distinct.
Isoetes nuttallii A. Braun ex Engelm.
Habit: Plant terrestrial. Leaf: deciduous, generally > 8 cm, > 1 mm wide at middle, rigid, +- brittle, tapered to tip, light green to gray-green; base white to +- brown, outermost sterile, often surrounded by several black scales. Sporangia: membrane covering > 75%; male spores 0.02--0.03 mm, brown in mass; female spores 0.35--0.6 mm, +- shiny, +- tubercled. Chromosomes: 2n=22.
Ecology: Seasonally wet soil, temporary streams; Elevation: generally < 1500(2760) m. Bioregional Distribution: NCoR, CaR, SN, ScV, n SnJV, CW (exc SCoRI), SCo, PR, w MP; Distribution Outside California: to British Columbia. Note: Spores mature late spring, summer.
Jepson eFlora Author: W. Carl Taylor & Jon E. Keeley
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Isoetes howellii
Next taxon: Isoetes occidentalis

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Botanical illustration including Isoetes nuttallii

botanical illustration including Isoetes nuttallii

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Citation for this treatment: W. Carl Taylor & Jon E. Keeley 2012, Isoetes nuttallii, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on December 08, 2023.

Citation for the whole project: Jepson Flora Project (eds.) 2023, Jepson eFlora,, accessed on December 08, 2023.

Isoetes nuttallii
click for enlargement
©2022 Neal Kramer
Isoetes nuttallii
click for enlargement
©2022 Neal Kramer
Isoetes nuttallii
click for enlargement
©2022 Neal Kramer
Isoetes nuttallii
click for enlargement
©2022 Neal Kramer
Isoetes nuttallii
click for enlargement
©2022 Neal Kramer

More photos of Isoetes nuttallii
in CalPhotos

Geographic subdivisions for Isoetes nuttallii:
NCoR, CaR, SN, ScV, n SnJV, CW (exc SCoRI), SCo, PR, w MP
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).