WeedsWeeds

Plant BodyPlant Body

• Shoot system = Shoot system = leaves + stemleaves + stem

• Root systemRoot system

• Meristem = cells Meristem = cells that divide for life that divide for life of plant, can give of plant, can give rise to all plant rise to all plant structuresstructures

Plant BodyPlant Body

BladeBlade

PetiolePetiole

Leaf = blade + petioleLeaf = blade + petiole

FunctionsFunctions Exposes surface to sunlightExposes surface to sunlight Major site of photosynthesis Major site of photosynthesis Conserves water Conserves water Provides for gas exchange Provides for gas exchange

Plant BodyPlant BodyStemStem

FunctionsFunctions

Holds leaves up to lightHolds leaves up to light

Transport of substances Transport of substances through vascular tissue through vascular tissue

Xylem conducts waterXylem conducts waterand minerals and minerals

Phloem transportsPhloem transports sugar sugar

Plant BodyPlant BodyRootRoot

FunctionsFunctions

Anchors plant in Anchors plant in soil soil

Takes up water and Takes up water and minerals from soil minerals from soil

1 Tree Tobacco 1 Tree Tobacco Nicotiana glaucaNicotiana glauca

glauca = bluish-gray,glauca = bluish-gray,referring to leaf colorreferring to leaf color

Leaves contain high Leaves contain high levels of nicotenelevels of nicotene

Introduced from Introduced from South America by South America by missionaries, from missionaries, from imported grain or on imported grain or on purpose…?purpose…?

2 Cheeseweed 2 Cheeseweed Malva neglectaMalva neglecta

Seeds and leaves Seeds and leaves are edible. are edible.

Seeds are shaped Seeds are shaped like rounds of like rounds of cheese.cheese.

33 Castor BeanCastor Bean Ricinus communisRicinus communis

Ricin in seeds Ricin in seeds --used to kill a spy on London Bridge --used to kill a spy on London Bridge

--recently discovered in the US mail --recently discovered in the US mail --possible cancer treatment --possible cancer treatment

Oil from seeds has laxative and Oil from seeds has laxative and wound-healing properties.wound-healing properties.

4 Sweet fennel 4 Sweet fennel Foeniculum vulgareFoeniculum vulgare

• Petioles are eaten, Petioles are eaten, like celery.like celery.

• Folkways medicine: Folkways medicine: Dried Leaves may Dried Leaves may repel fleasrepel fleas

• Priests spread on Priests spread on mission floors for mission floors for fragrancefragrance

5 Scarlet Pimpernel 5 Scarlet Pimpernel Anagallis arvensisAnagallis arvensis

Folkways Medicine: Folkways Medicine: May repel witchesMay repel witches

Poisonous to humans Poisonous to humans and livestockand livestock

6 Poison hemlock 6 Poison hemlock Comium maculatumComium maculatum

Conin causes muscle Conin causes muscle paralysis, found in all paralysis, found in all parts of plant. parts of plant.

7 Filaree 7 Filaree (Storksbill)(Storksbill)

ErodiumErodium

• Fruit shape is long and Fruit shape is long and pointedpointed– Filaree comes from the Filaree comes from the

Spanish name for Spanish name for needleneedle

– Erodium refers to heronErodium refers to heron

• Young foliage is edibleYoung foliage is edible

8 Saltbush 8 Saltbush Atriplex canescensAtriplex canescens

Large numbers of Large numbers of nutritious seeds, nutritious seeds, Used by native Used by native Americans for flourAmericans for flour

9 Sweet clover 9 Sweet clover Melilotus albusMelilotus albus

Enhances production of Enhances production of cumarin by moldscumarin by moldsOriginal source of heparinOriginal source of heparinImportant source of honeyImportant source of honey

10 Opium poppy 10 Opium poppy Papaver somniferumPapaver somniferum

Morphine and codeine from Morphine and codeine from developing seed podsdeveloping seed pods

11 California Poppy11 California Poppy Eschscholtzia californicaEschscholtzia californica

Young foliage is edibleYoung foliage is edibleRoots used for toothacheRoots used for toothache

1212 White GoosefootWhite Goosefoot ChenopodiumChenopodium

Young foliage and Young foliage and seeds are edibleseeds are edible

13 Mexican Tea 13 Mexican Tea Chenopodium ambrosioidesChenopodium ambrosioides

Folkways Medicine: Seeds act against intestinal worms.

Dried plant is used as seasoning.

14 Horehound 14 Horehound Marubium vulgareMarubium vulgare

Member of Member of the Mint familythe Mint family

Flavoring in candy, Flavoring in candy, cough drops, and beercough drops, and beer

Folkways Medicine: Folkways Medicine: good for sore throatsgood for sore throats

15 California Mugwort 15 California Mugwort Artemisia douglasianaArtemisia douglasiana

Folkways medicine: Uses for intestinal, Folkways medicine: Uses for intestinal, respiratory and skin ailments.respiratory and skin ailments.

16 Jimson weed 16 Jimson weed Datura meteloidesDatura meteloides

All parts of plant have All parts of plant have alkaloids like atropine. alkaloids like atropine. --medical use --medical use --religious observances --religious observances by Native Americans by Native Americans --hallucinogen in the 60’s --hallucinogen in the 60’s

DANGEROUS! DANGEROUS! Recent hospitalizations Recent hospitalizations and deaths reported in and deaths reported in LA County. LA County.

17 Sea Fig17 Sea FigCharpobrotus chilensisCharpobrotus chilensis

• Edible fleshy fruit Edible fleshy fruit forms below the forms below the flowerflower

• Helps to stabilize soil Helps to stabilize soil on hillsides or sand on hillsides or sand near oceannear ocean

18 Tumbleweed18 Tumbleweed(Russian Thistle)(Russian Thistle)

Salsola tragusSalsola tragus

• Noxious weed = Noxious weed = targeted for targeted for eradication eradication

• Shoot breaks off Shoot breaks off close to base and is close to base and is pushed by wind to pushed by wind to distribute seeds.distribute seeds.

• Contains high levels Contains high levels of nitrates or soluble of nitrates or soluble oxalatesoxalates

19 New Zealand Spinach19 New Zealand SpinachTetragonia tetragonioidesTetragonia tetragonioides

• Leaves can be eaten Leaves can be eaten raw or cookedraw or cooked

• Contains harmless Contains harmless levels soluble levels soluble oxalatesoxalates

20 Water Cress 20 Water Cress Rorippa nasturtium-aquaticumRorippa nasturtium-aquaticum

• Leaves and shoots Leaves and shoots can be eaten. can be eaten.

• Rich in Vitamin CRich in Vitamin C

• Be sure it comes Be sure it comes from unpolluted from unpolluted waters!waters!

21 Wild celery 21 Wild celery Apium graveolensApium graveolens

• Escaped from Escaped from cultivationcultivation

• Petioles are eatenPetioles are eaten

• Wild plant has strong Wild plant has strong taste made milder by taste made milder by cookingcooking

22 Chicory22 ChicoryCichorium intybusCichorium intybus

• Root scrapings used Root scrapings used as coffee flavoring or as coffee flavoring or substitutesubstitute

• Leaves of Leaves of C. endivaC. endiva used in saladsused in salads

The pollen is a The pollen is a common respiratory or common respiratory or hay-fever allergen.hay-fever allergen.

23 Western Ragweed 23 Western Ragweed Ambrosia Ambrosia

• Young leaves are Young leaves are edibleedible

• One species is a One species is a noxious weednoxious weed

24 Sow Thistle 24 Sow Thistle

SonchusSonchus

25 Plantain25 Plantain Platago potagonicaPlatago potagonica

• Young leaves are Young leaves are edibleedible

• Folkways medicine:Folkways medicine:wound healing, wound healing, laxativelaxative

26 Curly Dock 26 Curly Dock Rumex crispusRumex crispus

• Young leaves are Young leaves are edibleedible

• Folkways medicine: to Folkways medicine: to treat cough, blood treat cough, blood pressure, itching, pressure, itching, sprainssprains

• Toxic to livestockToxic to livestock

27 Dandelion27 DandelionTaraxacum officinaleTaraxacum officinale

• Young leaves and roots Young leaves and roots are eaten are eaten

• Dried roots used as Dried roots used as coffee substitute coffee substitute

• Seeds dispersed by Seeds dispersed by windwind

28 Black Mustard 28 Black Mustard Brassica nigraBrassica nigra

• Young leaves are Young leaves are eaten eaten

• Seed oil used to make Seed oil used to make mustard mustard

• Possibly introduced by Possibly introduced by missionaries who missionaries who scattered it along the scattered it along the Camino Real to mark Camino Real to mark the way between the way between missionsmissions

29 Wild Radish29 Wild RadishRaphanus sativusRaphanus sativus

Scrapings from Scrapings from young roots or young young roots or young seed pods taste like seed pods taste like radishesradishes

30 Wild oats 30 Wild oats Avena fatuaAvena fatua

• Escaped from Escaped from cultivationcultivation

• Seeds are edibleSeeds are edible

31 English Ivy31 English IvyHedera helixHedera helix

• Juice causes skin Juice causes skin irritationirritation

• Berries and leaves Berries and leaves are toxicare toxic

A related species provides treatments for A related species provides treatments for Hodgkin’s disease, leukemia and other Hodgkin’s disease, leukemia and other cancerscancers

32 Periwinkle Vinca major

33 Garden Nastursium33 Garden NastursiumTropaeolum majusTropaeolum majus

• Leaves are eaten in Leaves are eaten in saladssalads

• Hallucinogenic Hallucinogenic properties unprovenproperties unproven

34 Blue Gum34 Blue Gum EucalyptusEucalyptus

Eucalyptus globosusEucalyptus globosus

Added as a Added as a flavoring to flavoring to candies and candies and cough medicinescough medicines

35 Spurge35 SpurgeEuphorbia Euphorbia

• Milky sap (latex) Milky sap (latex) causes skin irritationcauses skin irritation

• Relative of the Relative of the mildly-toxic mildly-toxic Poinsettia plantPoinsettia plant

• Cardiac glycoside acts as Cardiac glycoside acts as – Medicinal heart stimulantMedicinal heart stimulant– Arrow poisonArrow poison– Insect defense mechanismInsect defense mechanism

36 Narrow-Leaf 36 Narrow-Leaf Milkweed Milkweed Asclepias Asclepias

37 White and 37 White and Purple NightshadePurple Nightshade

SolanumSolanum• Berries are poisonousBerries are poisonous• Relatives of the potatoRelatives of the potato

WorksheetWorksheet

• Complete page 169 from lab manualComplete page 169 from lab manual

• Be sure your instructor checks your Be sure your instructor checks your completed worksheet before you leave completed worksheet before you leave the labthe lab