Table Of ContentAlaska Plant Materials Center
F i e l d G u i d e
Terrestrial Weed Identification
2nd Edition 2014
This publication has been funded in
part under the American Recovery and
Reinvestment Act of 2009.
The Alaska Division of Agriculture, Plant
Materials Center supports the Agricultural
Industry by providing testing, production,
development, and distribution of seed and
other plant materials. To learn more about
the Alaska Plant Materials Center programs
and regulations, please visit
http://plants.alaska.gov/.
Cover Photo:
Alaska Plant Materials Center
F i e l d G u i d e
Terrestrial Weed Identification
2nd Edition 2014
Table of Contents
1 Introduction
3 How To Use This Guide
5 Glossary
Key Terms, Definitions
9 Tools
Measurements, Conversions
11 Invasive Weeds
11 .....Garlic Mustard Alliaria petiolata
13 .....Wild Oats Avena fatua
15 .....Cheatgrass Bromus tectorum
17 .....Spotted Knapweed Centaurea stoebe
19 .....Canada Thistle Cirsium arvense
21 .....Bull Thistle Cirsium vulgare
23 .....Narrowleaf Hawksbeard Crepis tectorum
25 .....Scotch broom Cytisus scoparius
27 .....Quackgrass Elymus repens
29 .....Leafy Spurge Euphorbia esula
31 .....Hempnettle Galeopsis tetrahit, Galeopsis bifida
33 .....Giant Hogweed Heracleum mantegazzianum
35 .....Orange Hawkweed Hieracium aurantiacum
37 .....Yellow-Flowered Hawkweeds
Hieracium caespitosum
H. umbellatum
39 .....Ornamental Jewelweed Impatiens glandulifera
41 .....Oxeye Daisy Leucanthemum vulgare
43 .....Yellow Toadflax Linaria vulgaris
45 .....Purple Loosestrife Lythrum salicaria
47 .....White & Yellow Sweetclover
Melilotus alba, M. officinalis
49 .....Reed Canarygrass Phalaris arundinacea
51 .....Wild Buckwheat Polygonum convolvulus
53 .....Japanese Knotweed Polygonum cuspidatum
55 .....Tansy Ragwort Senecio jacobaea
57 .....Perennial Sowthistle Sonchus arvensis
59 .....Common Tansy Tanacetum vulgare
61 .....Western Salsify Tragopogon dubius
63 .....Bird Vetch Vicia cracca
65 Common Weeds
65 .....Shepherd’s Purse Capsella bursa-pastoris
67 .....Lambsquarters Chenopodium album
69 .....Field Bindweed Convolvulus arvensis
71 .....Foxtail Barley Hordeum jubatum
73 .....Hawkbit/Fall Dandelion Leontodon autumnalis
75 .....Common Peppergrass Lepidium densiflorum
77 .....Bigleaf Lupine Lupinus polyphyllus
79 .....Pineapple Weed Matricaria discoidea
81 .....Common Plantain Plantago major
83 .....Prostrate Knotweed Polygonum aviculare
85 .....Creeping Buttercup Ranunculus repens
87 .....Corn Spurry Spergula arvensis
89 .....Common Chickweed Stellaria media
91 .....Common Dandelion Taraxacum officinale
93 .....Alsike Clover Trifolium hybridum
95 Works Cited
Introduction
Invasive weeds are introduced plant
species whose presence does, or is likely to,
cause harm to the economy, environment,
or human health. Invasive plants are capable
of reproducing in large numbers and are
difficult to control.
Alaska has long been considered isolated
from many of the invasive weed challenges
faced elsewhere in North America. Our
relatively cool climate and remote location
have kept many invaders out, but in recent
years, land managers in Alaska have become
acutely aware of the increasing populations
of invasive weeds in our urban areas, on our
roadsides, and even in our waterways.
The Alaska Department of Natural
Resources, Division of Agriculture,
maintains programs and regulations aimed
at managing invasive weeds through
inventory, control, coordination, and
outreach efforts statewide. The Plant Health
and Quarantine Regulations (11 AAC 34)
identify noxious weeds that are prohibited
or restricted based on their use in the
state of Alaska. You will see this ‘noxious’
designation throughout the book for
plants that can be found in the regulations.
Please refer to http://plants.alaska.gov/pdf/
SOA-seed-regs.pdf for the full and current
regulations.
1
This guide is intended to be a resource for
the identification and management of some
of Alaska’s invasive and common weeds
throughout the state. This is not a fully
comprehensive breakdown of all non-native
plants that occur in Alaska, but a selection
of the most abundant, or highest priority
invasive weeds as well as some of the more
commonly occurring, less aggressive
weedy species.
Throughout this guide the following terms
are used to describe and categorize plants:
• Noxious: A species of plant that is
considered a threat to natural resources
of the state and therefore has regulatory
restrictions which may include restrictions
on sale, transportation, or planting in
Alaska. A noxious plant has the capacity to
become destructive and difficult to control
once it is established.
• EDRR (Early Detection Rapid Response):
A species of invasive plant that is not
widespread in Alaska and is a high priority
for identification and eradication. This is
due to damage or aggressive behavior caused
by the species in other states, or biological
conditions which may allow the escape and
survival of this species in Alaska.
• Common: Non-regulated, less aggressive
weed species that are widespread in Alaska
and often warrant management in
some settings.
2
How to
Use This Guide
Common Name
Creeping (Canada) Thistle
Cirsium arvense
Latin Name
Distinctive Characteristics
Key points and • Perennial plant that grows 1-4
feet tall
characteristics of th• Ceo mmonly purple but can have white or
pink flowers
plant that are helpf•u Irlr egular-shaped, deep lobed, alternating leaves
• Distinguished spines on leaves
for identification. • Underside of leaf has soft, wooly hairs3
• Spreads by rhizomes and wind dispersed seeds
Common areas where Favored Habitat
• Fields, pastures, meadows, clearings,
the plant is most lik eanldy r oadsides
to be found. • Primarily in agricultural land and
disturbed sediments
Management
Methods proven Difficult to control once established. Hand
pulling is ineffective because of its rhizomatous
effective in controlrloiont sgys tem. A combination of mechanical,
the spread of weedcsu.ltural, and chemical methods has proven to be
the most effective.3
Seed Viability
Seeds can remain viable in the soil for up to
Additional notes ab2o0 yueatrs .3
Notes
the plant including Despite its name, the creeping/Canada thistle
history, use, and oWrgesintearlnly A casima,e a fnrdo mN oSrotuhtehrena Astferrinc aE. uThroepsee, spiny
information on toxipclanittsy ar;e rarely eaten by grazing animals, thus
have no biological control. Most infestations in
details of this sectioAnlas ka are concentrated in urban areas likely
being introduced by contaminated hay, straw,
are for informationoar lf orage and contaminated soil from nurseries
and landscapers.
purposes only.
17
All species are in alphabetical
order by Latin Name.
3
CCananaaddaa Th Thisitsltele InInvavsaisviev eW WeeededsCslassification
CiCrsiCriusimaum na raavrdevneasne sThe istle PrPorhoihbiibtietde dNI Nnoxovixaoisuoisuv sWe W Weeedeesdesds
Cirsium arvense Prohibited Noxious Weeds
DDiiDDssttiiiissnnttcciinnttcciivvtteeiivv CCeehh CCaahhrraaaarrccaattcceettrreeiissrrttiiiissccttssiiccss
•• IP••ru r eIPrrgpuruelrlegap,ur lPlleyai, r nSPlyhki an Saphknea ddap,DDn/e Doddiir,ess/ DeoWttpreiil ennyhWp iccLltyhoett b iLiiFtevvoelsob ee,F ewA lsCCol,e thhwAreraalentrerrartaaninaccgttti nleeegarr vleiieasssvtteiisccss
• Y•e lYlo•e wl lPoisuwhri psshlpe i,sn pPeiisnn oeksn ao nlneda l/veoearsv Weshite Flower
• U• n Ud•ne rdIsreirdresgeiu doleafr loleyfa Slfeh haafap seh das,os D ftseo, eftwp,lo ywo Lloloyob lhelysa, ihAraslt i3errsn 3ating leaves
• G• r Go•wr o sYw 1els-l 4o1 w-ft4i tsftahl ltsaplilnes on leaves
• S•p rSe•pa r dUesan dvdsiae v rRisaihd Riezh ooimzf oleemsa fae nsh daasn w dsoi nwftdi, n wddios dopileslryps eherdasi esrdes e3sdeseds
• Grows 1-4 ft tall
• Spreads via RhizomFFeaas FFvvaaaoonvvdrroo eewrrddieen HHdddaa dHHbbiaasiipttbbeaaiirttttseaadtt seeds
WWeeWWtt ltaeeontt l dtmaon m edms aimecrs gmaiicrn egmsaindesoawdoswsRWiveRWeti rvde Setit rldco FFShiuaatlecogvvshhu ooesgsrrh eesdd HHaabbiittaatt
StrSetarmeWa mbeat nbtoka nsmkessic meadoSwhaSsdheaR dIniev tIeonrl teSorllaoenurtag n7hts 7
RipRairpiWSRaatrnirepie atFaalnraom inrFae donbs r tamFesnsoaktrrssegsitnss WSMMheaaatMMd nndeaa iaaItnnncgghtaaeeoeggmmlseee reemmannneetttnn 7tt Photo(s) of the plant
DinigffiDi niiscgffi u iinlsct eu itffnlotee tccffootei nvccotteri nvboteler coboanle ucocsaeneu ce soeseft e aiostbftsl a iirtsbhshl iierszhdhoi.emz HdoMMa.ma tHnoaaaudatnnnos paa udruggos pl oeelru-tomm lolee-t nntt
sysstyesmtDe.m iAffi. ccAou mlcto btmoin bcaoitnnioattnrioo oln fo monfc emec heesactnhaibacnlaiislc,h acelud, lc.t uuHlrtaaunlr da lp ull-
andan cdhi necmgh eiismc aiinlc emaffl eemtchteoitvhdeos b dhesac sha uapsrs oep vroeofn vi tetsno r tbhoei z btohem et hamteo omussto rsot ot
effeecffteisvcytesi.v t3eem. 3. A combination of mechanical, cultural
and chemical methods has proven to be the most
effective. 3 SeeSede Vdi aVbiailbiitlyity
SyeeaeSyrdeessae. rdc3sas. nc3 arnem reamina ivnia vbilaeb ilne itnh et hseo isl ofiolSr fe ouerpd u t poV it2ao0 b 2i0l ity
Syeeaerdss. c3an remain viable in the soil NfoorN tuoepts teos 20 Jac qJauceqlyune lSycnh Sacdhea –d eP l–a nPtl aMnta tMeraitaelrsi Cales nCteern t–e rS t–a tSet aotfe A olfa Asklaaska
Thbe Thbee eae tenee atneitnr eretnai prw rela a opwnrlt a o cniorst o ceikods eoiebdkdl eeiabd.n lTh eda.n tThedh r etoe hs orteeto ssmo taetsnsm cdaasn lnced aa blnveee a bsev eaceN taseeo nanctt a eenns Jacquelyn Schade – Plant Materials Center – State of Alaska
whwenh eThcno oec koeeondkt.ie rCde. h pCelawhneitnw igis n tehgd eti hbrolee or. toTh ohtae sh r aboseo ebtnse eaunns deud sle eadv es can
teahns evteaa hins arr ebvoea bwaiim anlrrseibhoem t eaiemyenld ea inrmttyenteo ye dcmtef naootcynol eaor r tf du sakaocttysolwearr e ud seof t tsootsn.or sherrCeoi tacstctnrhcasohoaie huotactowreescatkae h.huip te n2aeestd4ohgce .Cpi h e2astt4oao enhh pCin.ndees l2aaa o i 4rpntdnn noChlgaataioe a n dntit tnonsgh athta ietaiCtsadonhmctsaa l ci aeC tsbsuttc t hehalcmlceeetiaau ts nunishltmfe l- aueb uis sefh -e eadas ten Kasn doowcnu mloecnattieodn bs y
filartsefilta rmrtseette co hmrnoreeverco d iaonrreberoidd itnnl reiimanitdtyt reePi atn natot heltP mac aatlanhe lusmr atis rntieen ern si n t1iosn i9 nrtc 4mr1oaa69urta 4measl6nle pya dat lowh nlhyiedsoa o w usphn ollsadaiiusnnn. lsgc1tdi e Int.it onsc 1wp e IaCt rasc ewsapca truadteslm ae d ui f- the Alaska Exotic
to StoC S AlCalt aAes klmaaso,k Fraea, iFnrbaitiarrnbaktaesn ,tk Dhs,ae Dnlt aei tlJt unan oJcurtmniocantli,ol yAn w,f oAogfunolagdkn. a1 kIt was Plant Information
IslaInslda,nfi adrns,t da r nCedcoo Clrddo Beldda yBi.n a3 yP. a3lmer in 1946 and has since spread
to SC Alaska, Fairbanks, Delta Junction, Afognak Clearinghouse as of
5656Island, and Cold Bay. 3 pub5l7i5c7ation date
56 57
4
Glossary
Alternate: Leaves occurring one at a node.4
Annual: A plant that produces seed and dies
within one year of germinating
from seed.4
Auricle: Having small ear-shaped lobe
or appendage.3
Awn: A slender, usually terminal bristle.3
Axil: The angle found between any two
organs or structures and the stem.
Basal: Situated at, or pertaining to,
the base.4
Biennial: A plant that flowers and takes two
years to complete its biological life.
Bract: A small leaf-like structure below
a flower.3
Calyx: The outer parts of a flower composed
of usually leaf-like parts called sepals.3
Corolla: The petals of a flower surrounding
the stamens and pistil.3
Cotyledon: The first leaf or leaves of a
seed plant.4
Germination: The development of a seed into
a plant.4
Glandular: Having or bearing secreting
organs or glands.4
Elliptic: Oval or oblong with rounded ends
and more than twice as long as broad.3
Entire: Leaf margins that are not cut or
toothed2 or having a margin devoid of any
indentations, teeth, or lobes.4
5
Description:Alaska Plant Materials Center Field Guide Terrestrial Weed Identification 2nd Edition 2014. 1 Introduction 3 How To Use This Guide 5 Glossary Key Terms, Definitions