Common Name: QUILLWORT FAMILY 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.
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 occidentalis L.F. Hend.
NATIVE Habit: Plant underwater. Leaf: evergreen, < 20 cm, rigid, brittle, tapered to tip, dark green; base brown-white. Sporangia: membrane covering < 50%; male spores 0.035--0.045 mm, gray in mass; female spores 0.5--0.7 mm, ridged, tubercled. Chromosomes: 2n=66. Ecology: Persistent lakes, pools; Elevation: > 1500 m. Bioregional Distribution: KR, SNH; Distribution Outside California: to British Columbia, Colorado. Note: Hybridizes with Isoetes bolanderi, Isoetes echinospora. Spores mature late summer. Synonyms: Isoetes lacustris var. paupercula Engelm. Jepson eFlora Author: W. Carl Taylor & Jon E. Keeley Index of California Plant Names (ICPN; linked via the Jepson Online Interchange) Previous taxon: Isoetes nuttallii Next taxon: Isoetes orcuttii
Botanical illustration including Isoetes occidentalis
Citation for this treatment: W. Carl Taylor & Jon E. Keeley 2012, Isoetes occidentalis, in Jepson Flora Project (eds.) Jepson eFlora, https://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=29404, accessed on April 19, 2024.
Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora, https://ucjeps.berkeley.edu/eflora/, accessed on April 19, 2024.
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(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.
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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.
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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).
