Index / Search / Isoetes howellii
§1 Plant
Isoetes howellii Engelm.
vernacular Howell's quillwort — species · Isoetaceae
§2Habit & range
Habit and range
- Growth habit
- Graminoid
- Duration
- Perennial
- Group
- Quillwort
- Family
- Isoetaceae Dumort.
- Genus
- Isoetes
§2a
Native status, by region
- CAN Canada Native
- L48 Lower 48 States Native
§2b
County-level range
· 51 counties across 5 states/territories§3Cultivation
No cultivation specs.
USDA has not characterised this taxon. Roughly four out of five plants in the database lack the detailed cultivation record present here — typically because they have not been the focus of NRCS Plant Materials work. Range and distribution data are unaffected.
§4Counties, by state
Recorded in 51 counties across 5 states/territories.
California view state ↗ 33 N ▾
- Amador 06005
- Butte 06007
- Contra Costa 06013
- Del Norte 06015
- El Dorado 06017
- Humboldt 06023
- Lake 06033
- Lassen 06035
- Madera 06039
- Marin 06041
- Mendocino 06045
- Merced 06047
- Monterey 06053
- Nevada 06057
- Plumas 06063
- Riverside 06065
- Sacramento 06067
- San Diego 06073
- San Luis Obispo 06079
- San Mateo 06081
- Santa Barbara 06083
- Santa Clara 06085
- Shasta 06089
- Sierra 06091
- Siskiyou 06093
- Sonoma 06097
- Stanislaus 06099
- Sutter 06101
- Tehama 06103
- Trinity 06105
- Tulare 06107
- Tuolumne 06109
- Ventura 06111
Idaho view state ↗ 1 N ▾
Oregon view state ↗ 11 N ▾
Utah view state ↗ 2 N ▾
Washington view state ↗ 4 N ▾
§5Sources & provenance
USDA PLANTS
Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.
plants.usda.gov/ISHO ↗GBIF Backbone
Canonical taxonomic identity, synonym resolution, cross-refs. CC0.
gbif.org/species/2688307 ↗Record version
Cached and built locally. Source version on this record:
usda-plants-mt-2026-05-26
fetched 2026-05-26T20:46:58Z