Species Details

Polygonum marinense

Marin knotweed

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Scientific Name:
Polygonum marinense Mertens & Raven
Common Name:
Marin knotweed
Family: Polygonaceae
Element Code: PDPGN0L1C0
USDA Plants Symbol: POMA15
Synonyms/Other Names:
CA Rare Plant Rank: 3.1
Fed List: None
State List: None
Global Rank: G2Q
State Rank:
S2
Other Status:
CRPR Changes:
changed from 3.1 to 3.1 on 2008-07-14
Add Date: 1974-01-01
Date Edited: 2021-05-26
Lifeform: annual herb
Blooming Period: (Apr)May-Aug(Oct)
JFMAMJJASOND
Elevation:
0 - 10 meters
0 - 35 feet
General Habitats:
  • Marshes and swamps (brackish, coastal salt)
Microhabitat Details:
Microhabitat:
Notes:
Move to List 1B? Known from fewer than twenty occurrences. Taxonomic status uncertain, related to P. aviculare; possibly synonym of P. robertii, a non-native plant. Immediate taxonomic study needed. Threatened by coastal development and foot traffic.
Threats:
Taxonomy:
Threat List Total: 9
Total EOs % of EOs
EOs with Threat Listed: 17 53 %
THREAT LIST:
Grazing 14 43%
Foot traffic/trampling 9 28%
Altered flood/tidal/hydrologic regime 2 6%
Development 1 3%
Erosion/runoff 1 3%
Total Occurrences: 32
Element Occurrence Ranks:
A B C D X U
2 13 9 0 0 8
Occurrence Status:
Historical >20 Years 27
Recent <=20 Years 5
Presence:
Presumed Extant 32
Possibly Extirpated 0
Presumed Extirpated 0
California Endemic:
California Island:
States: Name (Code)
California (CA)
California Counties and Islands: Name (Code)
Alameda (ALA), Contra Costa (CCA), Marin (MRN), Napa (NAP), San Francisco (SFO), Solano (SOL), Sonoma (SON)
Quads: Name (Quad Code)
Benicia (3812212), Bodega Head (3812331), Cuttings Wharf (3812223), Drakes Bay (3812218), Hunters Point (3712263), Inverness (3812217), Oakland East (3712272), Oakland West (3712273), Petaluma Point (3812214), Petaluma River (3812225), San Leandro (3712262), San Rafael (3712285), Tomales (3812228)
Notes:
Definitions of codes following a county and/or quad:
* Presumed extirpated
(?) Occurrence confirmed, but possibly extirpated
Quad and county data is imported from the CNDDB. Species may be present in other areas where conditions are favorable. These data should NOT be substituted for pre-project review or for on-site surveys.
Presumed Extant
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