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Earthshare of Washington

Home > Invasive Species

Collections Needed

Need help with identification? Try:

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Plants of Washington Image Collection

Snohomish County (34 taxa)

Scientific Name

Noxious

Weed Class

Phenology*
Collector**

Anthriscus sylvestris

B
5-8
 

Cardaria draba

C
5-6
 

Centaurea × moncktonii

B
8-9
 

Centaurea diffusa

B
7-10
 

Cirsium arvense

C
7-9
Mildred Arnot

Cirsium vulgare

C
7-10
Mildred Arnot

Clematis vitalba

C
7-10
David Gilblin w/Ben Legler

Convolvulus arvensis

C
5-10
 

Cyperus esculentus

B
8-10
 

Daucus carota

B
5-10
Ben Legler

Egeria densa

B
5-10
 

Geranium robertianum

B
4-8
 

Heracleum mantegazzianum

A
6-7
 

Hieracium aurantiacum

B
5-9
David Giblin w/Wendy Gibble, Ben Legler, Peter Zika

Iris pseudacorus

C
5-10
Ben Legler w/David Giblin, Mildred Arnot

Kochia scoparia

B
9-12
 

Linaria dalmatica

B
5-9
 

Lysimachia vulgaris

B
8-9
 

Lythrum salicaria

B
7-9
Ben Legler

Myriophyllum aquaticum

B
7-10
 

Myriophyllum spicatum 

B
8-10
 

Phalaris arundinacea

C
5-10
Mildred Arnot

Polygonum sachalinense

B
7-10
 

Polygonum polystachyum

B
8-10
 

Rorippa sylvestris

Monitor
7-8
 

Rorippa nasturtium-aquaticum

Monitor
4-9
 

Secale cereale

C
5-8
 

Senecio jacobaea

B
7-10
Ben Legler

Silene latifolia subsp. alba

C
4-8
 

Solanum rostratum

A
8-9
 

Soliva sessilis

A
5-6
Ben Legler

Sonchus arvensis

B
7-9
Ben Legler w/David Giblin, Mildred Arnot

Spartina alterniflora

B
9
 

Ulex europaeus 

B
4-9
 

* The numbers represent months of the year when the species has been collected, extracted from herbarium labels at WTU (with a few dates based on records at MO, NY, UC, and UBC).

On-line data sources for phenology:

MO:    http://mobot.mobot.org/W3T/Search/vast.html

NY:     http://sciweb.nybg.org/science2/vii2.asp

UBC:   http://herbarium.botany.ubc.ca/herbarium_data/vascular/search.htm

UC:     http://www.mip.berkeley.edu/www_apps/smasch/

WTU:   http://biology.burke.washington.edu/herbarium/collections/vascular/basicsearch.php

** email wnps@wnps.org when you've made a collection and we will put your name onto the list, this will help us minimalize duplication of efforts.  Use the email subject line:  Herbarium Collection