REDROOT PIGWEED Science PageDID YOU KNOW?One redroot pigweed plantcan produce over 100,000seeds! Some can live up to40 years in the soil.

ORIGINSRedroot pigweed is native

to tropical America.Today it can be

found onevery

continent.

NativeAmericans of North Americahave traditionally used redrootpigweed as a vegetable and agrain crop.

THE REDROOT PIGWEED PLANTRedroot pigweed is an annual. Theplant can reach to 2 meters (61/2 ft)high in one growing season.

It flowers in latesummer and fall.

The stemsare reddishand hairy.

Thetaprootis red.

The leavesare diamond-shaped andrough.

CLASSIFYING REDROOT PIGWEEDFAMILY

AmaranthaceaeIn Greek, this means everlasting.

Amaranth flowers last much longerthan most other flowers.

GENUSAmaranthus

SPECIESretroflexus

In Latin this means“bent back.”

FRIEND. . .Small plants thatdo not yet have flowers are used insalads or are cooked like spinach.The seeds can be roasted andground to make flour. The whole

seeds can becooked to makecereal.

The seeds arefood for manyinsects, birds, andmammals.

. . .OR FOE?

Farmers andgardenersconsiderredrootpigweed tobe one of theworst weeds.Each plantcan producethousands oflong-lastingseeds thatcan sproutand grow inalmost anysoil.

The specieswas given thisname bySwedishnaturalist, CarlLinnaeus, in1753. We stilluse the nametoday.

Since ancient times, people have usedplants in this genus as a grain crop, avegetable, adecorativeflower,and fordyingcloth.

A. gangeticus(leafy

vegetable)

The black, shiny seedssprout and grow in latespring and earlysummer when the soilbecomes warm.

I’m hoeing out thisredroot pigweedbefore it goes toseed. They say,

“One year ofseeding meansseven years of

weeding!”

Tiny seeds areinside the fruit.

The fruit grows from the flower.

Flowers growtogether ona spike.

A. cruentus(grain)

A. caudatus(ornamental flower)

redrootpigweed

house finch

seed

fruit

flower

Small greenflowers aretightlypacked intall spikesat the top ofthe plant.

Some flowersare also inclusters alongthe stem.

Male and femaleflowers grow on thesame plant.

Garden Mosaics is funded by the National Science Foundation Informal Science Education program, and by the College of Agriculture and Life Sciences at Cornell University.

GA

RD

EN

MO

SA

ICS

(ww

w.g

arden

mosa

ics.

org

)

PUZZLE

STIR-FRIED PIGWEED WITH COCONUTThis delicious recipe is from Southeast Asia, where pigweed leaves are often eaten asvegetables.Serves 4-6

Ingredients* 4 cups (1 liter) young redroot pigweed

leaves* 2 tablespoon (30 ml) oil* 1 onion, finely chopped* 1 teaspoon (5 ml) crushed garlic* 1 teaspoon (5 ml) grated fresh ginger* 1/2 teaspoon (2.5 ml) ground turmeric* 1 teaspoon (5 ml) chili powder* 1/4 teaspoon (1.3 ml) salt or to taste* 3 tablespoon (45 ml) dried coconut flakes

Instructions1. Wash the leaves and shake off the

water. Roll them in a bundle and chopfinely.

2. Heat the oil and fry the onion, garlic,and ginger over low heat, stirringfrequently, until onions are soft.

3. Add the ground tumeric and chilipowder, then the leaves. Stir-fry for aminute, and then sprinkle with salt anda few tablespoons of water.

4. Mix in coconut.5. Cover and simmer for 5 minutes.6. Serve with rice.

Garden Mosaics is funded by the National Science Foundation Informal Science Education program, and by the College of Agriculture and Life Sciences at Cornell University.

Using Pigweed to Clean Up Polluted SoilAt many nuclear weapons testing sites, soil

is polluted with radioactive wastes. Also, somenuclear power plants accidentally releaseradioactive wastes, which end up in the soil.Removing all this polluted soil would costhundreds of billions of dollars.

However, it is very important to clean upthese soils, because radioactive wastes are veryharmful to human health. The wastes can betaken into the body by eating food grown inpolluted soil. They can also be taken in bybreathing polluted air or drinking polluted water.Once in the body, these wastes give off radiationthat can cause cancer.

Scientists have been searching for cost-effective ways to clean up polluted soils. Theyhave discovered that some plants can take upradioactive wastes through their roots. Thewastes collect in the plant shoots withoutharming the plants. Once fully grown, the plants

can be removed from the area. In this way, thesoil can be cleaned up.

Scientists at Cornell University grew threeplant species in polluted soil at the BrookhavenNational Laboratory in New York State. Nucleartesting took place at this site in the 1950’s and1960’s. The scientists tested how well the plantscould take up radioactive cesium and strontiumfrom the polluted soil. They discovered thatredroot pigweed took up more radioactivecesium and strontium than the other two plantspecies, partly because it grew the fastest andbiggest. They estimate that if they grow twocrops of redroot pigweed a year, it will take 7years to clean up half the radioactive strontium,and 18 years to clean up half the radioactivecesium at this site.SOURCE: Fuhrmann, M., Lasat, M., Ebbs, S., Cornish, J., & Kochian,L. (2003). Uptake and release of cesium-137 by five plant species asinfluenced by soil amendments in field experiments. Journal ofEnvironmental Quality 32(6), 2272 - 2279.

Answers to puzzle:1(c);2(b); 3(c)

CAUTION: Never pick weeds to eat unless you are verysure you can identify them. Do not harvest weeds thatgrow near roadsides or that may have been sprayed withchemicals. These plants may not be safe to eat. Only eatyoung redroot pigweed plants. Do not eat redrootpigweed that has grown on heavily fertilized soil. It maycontain toxic amounts of nitrogen, and taste bitter.

Ha! Ha!Ha! Ha!

Ha! Ha!Ha! Ha!

JOKE

GA

RD

EN

MO

SA

ICS

(ww

w.g

arden

mosa

ics.

org

)

Charmaine Solomon’s Encyclopedia of Asian Food, PeriplusEditions, 1998, supplied courtessy of New Holland Publishers(Australia) Pty Ltd.

Fill in the blanks using one of the numbers atthe end of the sentences:1. A redroot pigweed seed can lie in the soil for

over ______ years before sprouting.(a) 5 (b) 20 (c) 40

2. A pigweed plant can grow ______ metershigh.(a) 1 (b) 2 (c) 3

3. A redroot pigweed plant may produce______ seeds.(a) 100 (b) 1,000 (c) 100,000

SPOTLIGHTON RESEARCH