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how to identify seeds in weed

What is a Weed? Tips for Weed Identification In Your Garden

Want to know how to identify weeds in your home garden? Believe it or not, the secret to weed identification is that it’s all about perspective! Read on for my tips on how to identify weeds and what to do about them. It may not be what you expect.

What Do Weeds Look Like: A Childhood Perspective

I remember picking bouquets of dandelions as a child: grabbing so many in my hand that I couldn’t keep my fingers around the flowers that kept falling out. It took some time to hone my picking skills, and sometimes the head would pop off, but luckily, there were plenty of blooms for me to practice on in the local park.

Dandelion (Taraxacum officinale) growing in the rocks.

I also remember blowing the little parachutes into the wind from a dandelion who had gone fully to seed and watching them float in the air, touching down where they would grow next. It’s a classic childhood thing to do because, for kids, the superfood dandelions are just about the most fun flower around!

Today, I’m certain that my neighbours will not mind if my son picks their dandelion blooms, and I’m equally as certain that they would cringe to see him blow the seeds into their yards.

So what is it about these sunny, yellow flowers that get people all worked up?

I mean, if you think about it, you can even buy dandelion seeds. So… are dandelions (Taraxacum officinale) weeds? And if so, what makes them weeds?

What is a Weed: A Plant Lover’s Perspective

You may be reading this and thinking “a dandelion is obviously a weed. Just look at them. They take over gardens and beautiful yards of grass. That obviously makes them a weed, right?”

If you are now scratching your head and wondering “how do I identify weeds in my yard?”, then you have come to the right place because I’m going to tell you.

A weed is simply a plant that is growing where it is not wanted.

If you have a bunch of rogue tomato or squash plants in your garden, they are called “volunteers”. However, if you have fairly hardy, native, or invasive plants growing where you didn’t plant it, that’s a “weed.” If you have a few pop up in the middle of the flower bed, that is a “wildflower.”

They are all the same thing.

Dead nettle (Lamium purpureum)

The reason weeds are seen as a garden problem at times is because they compete with plants who prefer garden space, nutrition, and water. Left to their own devices, the weeds will probably win.

They are stronger, faster-growing, and relentless in the garden. They can come back from a tiny thread of root left behind and bury themselves so deep you will lose your shovel before you get them all. Or, they can grow sideways out under rocks, pots, or landscape fabric.

The seeds can also stay dormant for hundreds of years before the right conditions allow them to germinate.

Stinging Nettle (Urtica dioica)

Weeds Aren’t Bad: There Are Many Benefits

Weeds get a bad rap, and I’ll admit, sometimes I’m not thrilled about them either (like when my bindweed tries to claim control over my garden). However, there are a few benefits to weeds:

  • They are an important food source for insects, birds, and wildlife.
  • Many are edible, tasty, nutritious, and medicinal.
  • They cover bare soil quickly, holding in water and nutrition.
  • They can also draw water and nutrients from deep in the soil via those long taproots that make them so hard to pull up.
  • Compost these weeds, and those nutrients will feed your garden.

Weed Identification: How to Identify What is a Weed in Your Garden

You can certainly search the web for weed identification and it will bring up plenty of charts. The methods I generally use don’t require any books or a computer screen, though.

In most cases, I will let the plant in question grow and see what happens. If it seems that this little seedling will soon be a monster taking over my beautiful peony, then, yoink! It’s off to the compost bin.

If it’s peppering the lawn with flowers as clover does, I’ll happily leave that for the bees to enjoy. The bees have enough problems these days without me taking their food sources away.

Chickweed (Stellaria media) -yum!

Identifying Weeds in the Vegetable Garden

In the vegetable garden, I teach children to identify weedlings before they take over the veggie plot.

Generally, if a tidy row of similar-looking greenery is growing in an orderly fashion where you planted some seeds, it’s likely cultivated. You can certainly check a photo of vegetable seedlings on the internet to confirm, but pattern goes a long way here.

Clusters of random-looking greens or sprouts where you didn’t plant seeds are probably wild plants. If you are still in doubt, the wait-and-see method works every time!

This doesn’t mean you need to let your entire garden grow to maturity before you realize that it’s just all buttercup. It’s simply the technique that I use to start identifying what I want and what I don’t want growing in the garden.

There are plenty of plants that aren’t typically characterized as weeds that I rip out of the beds just as quickly as I would some dreaded horsetail. With this, you are learning about your garden, the plants that naturalize there, and their habits.

If you identify a weed that looks beautiful when blooming that you want to keep for a short spell (like those darling forget-me-nots), just be sure to pluck that sucker from the soil before the flowers go to seed.

Enjoy it while you can, but be ruthless before you have hundreds to contend with!

But maybe you will like that too. It’s all perspective after all.

Plantain (Musa × paradisiaca) – delicious, medicinal, and a natural bandage

If you struggle with weed identification, I hope this post helped to give you confidence about knowing what is a weed and what is not.

More Reading on Wild Plants and Weeds

Want to embrace the wildness and eat some of the weeds? Check out these posts:

Resources Consulted

Fahn, A. 1990. Plant Anatomy, 4th ed. Butterworth Heinemann, Oxford, 588.

Harris, J.G. and Harris, M.W. 2001. Plant Identification Terminology, An Illustrated Glossary, 2nd Edition. Spring Lake Publishing, Spring Lake, Utah, 206 pp.

ITIS—Integrated Taxonomic Information System.
URL: http://www.itis.gov/

Pemberton, R.W. and Irving, D.W. 1990. Elaiosomes on weed seeds and the potential for myrmecochory in naturalized plants. Weed Science 38: 615–619.

Zomlefer, W.B. 1994. Guide to Flowering Plant Families. The University of North Carolina Press, Chapel Hill, 430 pp.

Sections

General Seed Identification

Baxter, D. and Copeland, L.O. 2008. Seed Purity and Taxonomy. Michigan State University Press, East Lansing, 719 pp.

Canadian Grain Commission. 2000. Visual Identification of Small Oilseeds and Weed Seed Contaminants, Grain Biology Bulletin No. 3. The Canadian Grain Commission, Winnipeg, Manitoba. 29 pp.

Davis, L.W. 1993. Weed Seeds of the Great Plains, A Handbook for Identification. University Press of Kansas, Lawrence, 145 pp.

Delorit, R.J. 1970. An Illustrated Taxonomy Manual of Weed Seeds. Agronomy Publications, River Falls, Wisconsin, 175 pp.

Gunn, C.R. and Ritchie, C.A. 1988. Identification of Disseminules Listed in the Federal Noxious Weed Act. United States Department of Agriculture, Agricultural Research Service, Technical Bulletin No. 1719, 313 pp.

Kirkbride, J.H., Jr, Gunn, C.R., and Dallwitz, M.J. 2006. Family Guide for Fruits and Seeds, Version 1.0.
URL: http://sbmlweb/OnlineResources/frsdfam/Index.cfm

Kulpa W. and Desowska, K. 1988. Quarantine or restricted seeds in international seed trade. Bulletin of Plant Breeding and Acclimatization Institute, Supplement Number 166: 1–98.

Martin, A.C. 1946. The comparative internal morphology of seeds. The American Midland Naturalist 36(3): 513–660.

Martin, A.C. and Barkley, W.D. 1961. Seed Identification Manual. University of California Press, Berkeley, Los Angeles, 221 pp.

Montgomery, F.H. 1977. Seeds and Fruits of Plants of Eastern Canada and Northeastern United States. University of Toronto Press, Toronto, 232 pp.

Muenscher, W.C. 1935. Weeds. MacMillan Company, New York, 577 pp.

Musil, A.F. 1963. Identification of Crop and Weed Seeds. USDA Agriculture Handbook No. 219, Superintendent of Documents, Washington, D.C., 214 pp.

Plant Protection and Quarantine, Animal and Plant Health Inspection Service, United States Department of Agriculture. 1980. Major Weed Family Identification Guide, 1st Edition. Creative Universal, Inc., Southfield, Michigan, 161 pp.

RSABG Seed Program Home. [Online database of seed photographs by John Macdonald.] Rancho Santa Ana Botanic Garden.
URL: http://www.hazmac.biz/seedhome.html

California Botanical

Calflora: Information on California plants for education, research and conservation. [Online database.] 2011. The Calflora Database, Berkeley, California.
URL: http://www.calflora.org/

California Department of Food and Agriculture. Encycloweedia: Data Sheets.
URL: http://www.cdfa.ca.gov/phpps/ipc/encycloweedia/weedomfpwinfo-table-sciname.htm

California Invasive Plant Council—CAL-IPC. 2006–2010.
URL: http://www.cal-ipc.org/

CalPhotos. [Online database of plant photographs.] University of California, Berkeley.
URL: http://calphotos.berkelet.edu/

Consortium of California Herbaria. [Online database of specimens located in major California herbaria.] 2010. The Regents of the University of California.
URL: http://ucjeps.berkeley.edu/consortium/participants.html

DiTomaso, J.M. and Healy, E.A. 2007. Weeds of California and Other Western States, Volumes 1 & 2. University of California, Agriculture and Natural Resources, Publication 3488, 1808 pp.

Fuller, T.C. and McClintock, E. 1986. Poisonous Plants of California. University of California Press, Berkeley, 433 pp.

Grape Weed Photo Gallery With Common and Scientific Names. 2008. Statewide IPM Program, Agriculture and Natural Resouces, The Regents of the University of California.
URL: http://www.ipm.ucdavis.edu/PGM/r302700999.html

Hickman, J.C., ed. 1993. The Jepson Manual of the Higher Plants of California. University of California Press, Berkeley, 1400 pp.

Meyer, D.J.L. and Effenberger, J. 2004. California Noxious Weed Disseminules Identification Manual. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Robbins, W.W., M.K. Bellue, and Ball, W.S. 1951. Weeds of California. Printing Division (Documents Section), Sacramento, 547 pp.

The Jepson Online Interchange: California Floristics. [Online database including the Treatment from the Jepson Manual, 1993, and DRAFT of Jepson Manual II: Vascular Plants of California, ongoing.] The Regents of the University of California.
URL: http://ucjeps.berkeley.edu/interchange/

Australia Botanical

FloraBase: the Western Australian Flora. Western Australian Herbarium, Department of Environment and Conservation.
URL: http://florabase.dec.wa.gov.au/

New South Wales Flora Online. Botanic Gardens Trust, Sydney, Australia.
URL: http://plantnet.rbgsyd.nsw.gov.au/floraonline.htm

Quarantine Proclamation 1998. Australian Government.
URL: http://www.comlaw.gov.au/Series/F1998B00158

Sharp, D. and Simon, B.K. 2002. AusGrass: Grasses of Australia. CD-ROM (Lucid), Version 1.0. Australian Biological Resources Study, Canberra, and Environmental Protection Agency, Queensland.

Tropical Forages. Australian Government.
URL: http://www.tropicalforages.info/

Table Grapes from the USA. Australian Government.
URL: http://www.daff.gov.au/ba/ira/final-plant/tablegrapes-usa

New Zealand Botanical

Biosecurity Organisms Register for Imported Commodities. New Zealand Government.
URL: http:www.maf.govt.nz/biosecurity/pests-diseases/registers-lists/boric/

Flora of New Zealand Series. 2004. Landcare Research.
URL: http://floraseries.landcareresearch.co.nz/pages/Index.aspx

Import Health Standard Commodity Sub-class: Fresh Fruit/Vegetables: Table grapes, (Vitis vinifera) from the United States of America — State of California. May 3, 2010. New Zealand Government.
URL: http://www.biosecurity.govt.nz/files/ihs/grape-us.pdf

MAF Biosecurity Authority Plants Biosecurity Index. New Zealand Government.
URL: http://www1.maf.govt.nz/cgi-bin/bioindex/bioindex.pl

Webb, C.J. and Simpson, M.J.A. 2001. Seeds of New Zealand gymnosperms and dicotyledons. Manuka Press, Christchurch, 428 pp.

Other USA Botanical

Agricultural Research Service, United States Department of Agriculture. 1970. Selected Weeds of the United States. Superintendent of Documents, United States Government Printing Office, Washington, D.C., 463 pp.

Agricultural Research Service, United States Department of Agriculture. 1971. Common Weeds of the United States. Dover Publications, New York, 463 pp.

Flora of North America.
URL: http://www.efloras.org/flora_page.aspx?flora_id=1

Germplasm Resources Information Network — (GRIN) [Online database]. National Germplasm Resources Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland.
URL: http://www.ars-grin.gov/cgi-bin/npgs/html/tax_search.pl

SEINet—Southwest Environmental Information Network.
URL: http://swbiodiversity.org/seinet/

The Plant List. 2010. Version 1.
URL: http://www.theplantlist.org/

The PLANTS Database. 2010. Natural Resources Conservation Service, United States Department of Agriculture, National Plant Data Center, Baton Rouge, Louisiana.
URL: http://plants.usda.gov/

Washington State Noxious Weed Control Board.
URL: http://www.nwcb.wa.gov/

Other Countries Botanical

Afonin, A.N., S.L. Greene, N.I. Dzyubenko, A.N. Frolov (eds.). 2008. AgroAtlas—Interactive Agricultural Ecological Atlas of Russia and Neighboring Countries.
URL: http://www.agroatlas.ru/

E-Flora BC: Electronic Atlas of the Plants of British Columbia. 2008.
URL: http://linnet.geog.ubc.ca/

Flora of China.
http://www.efloras.org/flora_page.aspx?flora_id=2

Flora of Pakistan.
http://www.efloras.org/flora_page.aspx?flora_id=5

Global Invasive Species Database.
URL: http://www.issg.org/database/

International Plant Names Index (IPNI).
URL: http://ipni.org/

Pacific Island Ecosystems at Risk (PIER). Hawaiian Ecosystems at Risk project (HEAR).
URL: http://www.hear.org/pier/

Plants of Taiwan. 2009. [Includes online versions of Flora of Taiwan and Flora of Taiwan, 2nd. Ed.] Institute of Ecology and Evolutionary Biology, NTU.
URL: http://tai2.ntu.edu.tw/ebook/ebooksearch.php

Reed, C.F. 1977. Economically Important Foreign Weeds; Potential Problems in the United States. United States Department of Agriculture, Animal and Plant Health Inspection Service and Agricultural Research Service, Agriculture Handbook Number 498, 746 pp.

Zafar, M., Khan, M.A., Ahmad, M., and Sultana, S. 2006. Palynological and taxonomic studies of some weeds from flora of Rawalpindi. Pakistan Journal of Weed Science Research 12(1–2): 99–109.

Specific Plant Families

Alismataceae

Haggard, K.K. and Tiffney, B.H. 1997. The flora of the Early Miocene Brandon Lignite, Vermont, USA. VIII. Caldesia (Alismataceae). American Journal of Botany 84(2): 239–252.

Asteraceae

Funk, V.A., A. Susanna, T.F. Stuessy, and R.J. Bayer. (Editors). 2009. Systematics, Evolution and Biogeography of Compositae. International Association for Plant Taxonomy, Institute of Botany, University of Vienna. Vienna.

Meyer, D.J.L. 1999. Seed Unit Identification in the Asteraceae. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Brassicaceae

Berggren, G. 2006. Atlas of seeds and small fruits of northwest-European plant species (Sweden, Norway, Denmark, East Fennoscandia and Iceland) with morphological descriptions: part 3. Salicaceae-Cruciferae. Stockholm, Swedish Museum of Natural History, 259 pp.

Chapman, M.A. and Burke, J.M. 2006. Radishes gone wild. Heredity 97: 379–380.

Karcz, J., Ksiazczyk, T., and Maluszynska, J. 2005. Seed coat patterns in rapid-cycling Brassica forms. ACTA Biologica Cracoviensia Series Botanica 47(1): 159–165.

Murley, M.R. 1951. Seeds of the Cruciferae of Northeastern North America. The American Midland Naturalist 46(1): 1–81.

Price, R.A., Meyer, D.J.L., and Effenberger, J. 2010. Seeds and Fruits of Weedy Brassicaceae. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Tantawy, M.E., Khalifa, S.F., Hassan, S.A., and Al-Rabiai, G.T. 2004. Seed exomorphic characters of some Brassicaceae (LM and SEM study). International Journal of Agriculture & Biology 06(5): 821–830.

Zeng, C.-L., Wang, J.-B., Liu, A.-H., and Wu, X.-M. 2004. Seed coat microsculpturing changes during seed development in diploid and amphidiploid Brassica species. Annals of Botany 93: 555–566.

Convolvulaceae

Costea, M., Nesom, G.L., and Stefanovic, S. 2006. Taxonomic of the Cuscuta pentagona complex (Convolvulaceae) in North America. Sida 22: 151–175.

Costea, M., Nesom, G.L., and Tardif, F.J. 2005. Taxonomic status of Cuscuta nevadensis and C. veatchii (Convolvulaceae) in North America. Brittonia 57(3): 264–272.

Costea, M., Wright, M.A.R., and Stefanovic, S. 2009. Untangling the systematics of salt marsh dodders: Cuscuta pacifica, a new segregate species from Cuscuta salina (Convolvulaceae). Systematic Botany 34(4): 787–795.

Kanwal, D., Abid, R., and Qaiser, M. 2010. The seed atlas of Pakistan—III. Cuscutaceae. Pakistan Journal of Botany 42(2): 703–709.

Meyer, D.J.L. 2002. Important Seed Characters for Certain Species in Convolvulaceae and Other Closely Related Families. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Fabaceae

Meyer, D.J.L. and Effenberger, J.M. 1999. Descriptions of Selected Small-Seeded Legumes. Calfifornia Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Juncaceae

Abdel Khalik, K.N. 2010. Seed coat morphology and its systematic significance in Juncus L. (Juncaceae) in Egypt. Journal of Systematics and Evolution 48(3): 215–223.

Cope, T.A. and Stace, C.A. 1978. The Juncus bufonius L. aggregate in western Europe. Watsonia 12: 113–128.

Onagraceae

Tobe, H., Wagner, W.L., and Chin, H.-C. 1987. A systematic and evolutionary study of Oenothera (Onagraceae): seed coat anatomy. Botanical Gazette 148(2): 235–257.

Plantaginaceae

Kelley, W.R. 1953. Study of seed identification and seed germination of Potentilla spp. and Vernonica ssp. Cornell University Agriculture Experimental Station Memoir 317: 235–257.

Poaceae

Clayton, W.D., Vorontsova, M.S., Harman, K.T., and Williamson, H. 2010. GrassBase — The Online World Grass Flora. The Board of Trustees, Royal Botanic Gardens, Kew.
URL: http://www.kew.org/data/grasses-db/sppindex.htm

Grasses in North America [Online database representing information from the Flora of North America, Barkworth, M.E. et al. (eds), Volumes 24 & 25.]
URL: http://herbarium.usu.edu/webmanual

Harrington, H.D. 1977. How to Identify Grasses & Grasslike Plants. Swallow Press, Athens, 154 pp.

Meyer, D.J.L. and Effenberger, J. 2001. Identification of Poaceae Seed Units; Aegilops, Alopecurus, Phalaris, Setaria, Panicum, Urochloa. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Meyer, D.J.L. and Effenberger, J. 2004. Small-Seeded Weedy Grasses, Deschampia, Dinebra, Gastridium, Leptochloa, Polypogon, Ventenata. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Sharp, D. and Simon, B.K. 2002. AusGrass: Grasses of Australia. CD-ROM (Lucid), Version 1.0. Australian Biological Resources Study, Canberra, and Environmental Protection Agency, Queensland.

Watson, L. and Dallwitz, M.J. 1992 onwards. The Grass Genera of the World.
URL: http://delta-intkey.com/grass/www/index.htm

Polygonaceae

Meyer, D.J.L. and Effenberger, J. 2001. Identification of Polygonaceae Seed Units. California Department of Food & Agriculture, Plant Pest Diagnostics Center, Sacramento.

Portulacaceae

Nyffeler, R. and Eggli, U. 2010. Disintegrating Portulacaceae: a new familial classification fo the suborder Portulacineae (Caryophyllales) based on molecular and morphological data. Taxon 59 (1): 227–240.

Scrophulariaceae

Ghebrehiwet, M., Bremer, B., and Thulin, M. 2000. Phylogeny of the tribe Antirrhineae (Scrophulariaceae) based on morphological and ndhF sequence data. Plant Systematics and Evolution 220(3–4): 223–239.

Juan, R., Pastor, J., and Fernandez, I. 1999. Morphological and anatomical studies of Linaria species from south-west Spain: seeds. Annals of Botany 84: 11–19

Solanaceae

Agricultural Research Service in cooperation with Soil Conservation Service, United States Department of Agriculture. 1974. Seed Characteristics of 42 Economically Important Species of Solanaceae in the United States. Superintendent of Documents, United States Government Printing Office, Washington, D.C., 33 pp.

Axelius, B. 1992. Testa patterns in some species of Physalis L. and some other genera in the tribe Solaneae (Solanaceae). International Journal of Plant Sciences 153(3): 488–502.