weed families

Weed families

Learning weeds by plant families is one of the best ways to learn identification. Families often have common traits among different species that allow you to group weeds in your mind for easier ID. These family characteristics are also very helpful to begin ID of a new weed species.

Closely related to the plant family way of learning weed ID is the “species-group” concept discussed previously. Many of our most successful weed “species” are in fact a group of closely related, often inter-fertile, species. Learning these weed species-groups will aid you in learning weed ID.

Plant Family —-> Species-Group —-> Species —-> Variants

Cashew Family (Anacardiaceae) Family

poison ivy (Rhus radicans) woody perennial

Composite (Compositae) Family

common cocklebur (Xanthium strumarium) summer annual
dandelion (Taraxacum officinale) perennial
horseweed (Conyza canadensis) summer annual
common sunflower (Helianthus annuus) summer annual

The Thistle Species-Group:
Canada thistle (Circium arvense) perennial
Biennial Thistles:
-bull thistle (Circium vulgare) biennial
-[musk thistle (Carduus nutans) biennial]

The Ragweed Species-Group:
common ragweed (Ambrosia artimeisiifolia) summer annual
giant ragweed (Ambrosia trifida) annual

Dogbane (Apocynaceae) Family

hemp dogbane (Apocynum cannabinum) perennial

Gourd (Curcurbitaceae) Family

[bur cucumber (Sicyos angulatus) summer annual]

Grass (Graminaceae; Poaceae) Family

quackgrass (Elytrigia repens ) perennial
wirestem muhly (Muhlenbergia frondosa) perennial
[woolly cupgrass (Eriochloa villosa) summer annual]
barnyardgrass (Echinochloa crus-galli) summer annual
volunteer corn (Zea mays) summer annual
[field sandbur (Cenchrus incertus) summer annual, biennial]
[foxtail barley (Hordeum jubatum) perennial]

The Panicum Species-Group:
wild proso millet (Panicum miliaceum) summer annual
fall panicum (Panicum dichotomiflorum) summer annual
witchgrass (Panicum capillare) summer annual

The Foxtail Species-Group:
green foxtail (Setaria viridis) summer annual
bristly foxtail (Setaria verticillata) summer annual
giant foxtail (Setaria faberi) summer annual
yellow foxtail (Setaria glauca) summer annual
knotroot foxtail (Setaria geniculata) summer annual

The Crabgrass Species-Group:
large crabgrass (Digitaria sanguinalis) summer annual
smooth crabgrass (Digitaria ischaemum) summer annual

The Sorghum Species-Group:
shattercane (Sorghum bicolor) summer annual
johnsongrass (Sorghum halpense) perennial
sorghum-almum (Sorghum almum) summer annual

[The Bromegrass Species-Group]:
downy brome (Bromus tectorum) winter annual, summer annual
smooth brome (Bromus inermis) perennial

Hemp (Cannabaceae) Family

wild hemp, marijuana (Cannabis sativa; Cannabis indica) summer annual

Lambsquarters (Chenopodiaceae) Family

common lambsquarters (Chenopodium album) summer annual
[kochia (Kochia scoparia) annual]

Legume (Leguminosae; Fabaceae) Family

[black medic (Medicago lupulina) annual, biennial, perennial]

[Sweetclover species-group:]
yellow sweet clover (Melilotus officinalis) annual, biennial, perennial
white sweet clover (Melilotus alba) annual, biennial, perennial

Loosestrife (Lythraceae) Family

Mallow (Malvaceae) Family

velvetleaf (Abutilon theophrasti) summer annual
[venice mallow (Hibiscus trionum) summer annual]

Milkweed (Asclepiadaceae) Family

common milkweed (Asclepias syriaca) perennial

Mint (Labiatae) Family

[catnip (Nepeta cataria) perennial]

Morningglory (Convolvulaceae) Family

Bindweed species-group:
field bindweed (Convolvulvus arvensis) perennial
hedge bindweed (Calystegia sepium) perennial

Mustard (Cruciferae) Family

field pennycress (Thlaspi arvense) winter annual
shepard’s purse (Capsella bursa-pastoris) summer annual/winter annual
wild mustard (Sinapis arvensis) winter/summer annual

Nightshade (Solanaceae) Family

jimsonweed (Datura stramonium) summer annual

The Nightshade Species-Group:
eastern black nightshade (Solanum ptycanthum) summer annual
bitter nightshade (Solanum dulcamara) summer annual

Pigweed (Amaranthaceae) Family

The Pigweed Species-Group
redroot pigweed (Amaranthus retroflexus) summer annual
smooth pigweed (Amaranthus hybridus) summer annual
Powell pigweed (Amaranthus powellii) summer annual
spiny pigweed (Amaranthus spinosus) summer annual
tumble pigweed (Amaranthus albus) summer annual
prostrate pigweed (Amaranthus blitoides) summer annual
common waterhemp (Amaranthus rudis) summer annual
tall waterhemp (Amaranthus tuberculatus) summer annual
Palmer amaranth (Amaranthus palmeri) summer annual

Plantain (Plantaginaceae) Family

Plantain species-group:
Blackseed plantain (Plantago rugelii) perennial
Broadleaf plantain (Plantago major) perennial
Buckhorn plantain (Plantago lanceolata) perennial

Purslane (Portulacaceae) Family

purslane (Portulaca oleracea) summer annual

Rose (Rosaceae) Family

[multiflora rose (Rosa multiflora) perennial shrub

Sedge (Cyperaceae) Family

Smartweed (Polygoneaceae) Family

The Polygonum Species-Group
-wild buckwheat ( Polygonum convolvulvus ) summer annual
Knotweed Species-Group

-prostrate knotweed (Polygonum aviculare) summer annual
-erect knotweed (Polygonum erectum) summer annual
Smartweed Species-Group
-Pennsylvania smartweed (Polygonum pensylvanicum) summer annual
-ladysthumb (Polygonum persicaria) summer annual
-swamp smartweed (Polygonum coccineum) perennial

Weed families Learning weeds by plant families is one of the best ways to learn identification. Families often have common traits among different species that allow you to group weeds in your

How to Manage Pests

Identification: Weed Photo Gallery, All Categories

The UC IPM Weed Photo Gallery includes many, but not all, weed species commonly found in California farms and landscapes. Additional species will be added over time. Acknowledgments.

Click on table headings to sort columns 1 . Tip: Sort multiple columns simultaneously by holding down the shift key and clicking a second, third or even fourth column header.

Legend: = Ascending, = Descending, = Unsorted 1 Table sorting functions require Javascript.

Aquatics (Identification)—Top of page

Common Name Scientific Name Family Category
Arrowhead, California Sagittaria montevidensis Alismataceae (Waterplantain Family) Aquatic
Arrowhead, Gregg Sagittaria longiloba Alismataceae (Waterplantain Family) Aquatic
Bulrush, Ricefield Scirpus mucronatus Cyperaceae (Sedge Family) Aquatic
Bulrush, River Scirpus fluviatilis Cyperaceae (Sedge Family) Aquatic
Burhead, Upright Echinodorus berteroi (E. cordifolius) Alismataceae (Waterplantain Family) Aquatic
Cattails Typha spp. Typhaceae (Cattail Family) Aquatic
Ducksalad Heteranthera limosa Pontedericaceae (Pickerelweed Family) Aquatic
Naiads Najas spp. Hydrocharitaceae (Waterweed Family) Aquatic
Sedge, Smallflower Umbrella Cyperus difformis Cyperaceae (Sedge Family) Aquatic
Spikerush, Blunt Eleocharis obtusa Cyperaceae (Sedge Family) Aquatic
Sprangletop, Bearded Leptochloa fascicularis Poaceae (Grass Family) Aquatic
Waterhyssops Bacopa spp. Scrophulariaceae (Figwort Family) Aquatic
Waterplantain, Common Alisma plantago-aquatica Alismataceae (Waterplantain Family) Aquatic

Broadleaves (Identification)—Top of page

Common Name Scientific Name Family Category
Amaranth, Low Amaranthus deflexus Amaranthaceae (Pigweed Family) Broadleaf
Arrowhead, California Sagittaria montevidensis Alismataceae (Waterplantain Family) Broadleaf
Arrowhead, Gregg Sagittaria longiloba Alismataceae (Waterplantain Family) Broadleaf
Bassia, Fivehook Bassia hyssopifolia Chenopodiaceae (Goosefoot Family) Broadleaf
Bedstraw, Catchweed Galium aparine Rubiaceae (Madder Family) Broadleaf
Bindweed, Field Convolvulus arvensis Convolvulaceae (Morningglory Family) Broadleaf
Bittercress, Little Cardamine oligosperma Brassicaceae (Mustard Family) Broadleaf
Blackberries, Wild Rubus spp. Rosaceae (Rose Family) Broadleaf
Brassbuttons, Mexican Cotula Mexicana Asteraceae (Sunflower Family) Broadleaf
Brassbuttons, Southern Cotula australis Asteraceae (Sunflower Family) Broadleaf
Broomrape, Branched Orobanche ramosa Orobanchaceae (Broomrape Family) Broadleaf
Buckwheat, Wild Polygonum convolvulus Polygonaceae (Buckwheat Family) Broadleaf
Burclover, California Medicago polymorpha Fabaceae (Pea or Bean Family) Broadleaf
Burhead, Upright Echinodorus berteroi (E. cordifolius) Alismataceae (Waterplantain Family) Broadleaf
Burweed, Lawn Soliva sessilis Asteraceae (Sunflower Family) Broadleaf
Buttercup, Bermuda (Buttercup Oxalis) Oxalis pes-caprae Oxalidaceae (Oxalis Family) Broadleaf
Carrot, Wild Daucus carota Apiaceae (Carrot Family) Broadleaf
Catsear, Common Hypochaeris radicata Asteraceae (Sunflower Family) Broadleaf
Celery, Wild Cyclospermum leptophyllum Apiaceae (Carrot family) Broadleaf
Chamomile, Mayweed Anthemis cotula Asteraceae (Sunflower Family) Broadleaf
Chickweed, Common Stellaria media Caryophyllaceae (Pink Family) Broadleaf
Chickweed, Mouseear Cerastium fontanum ssp. vulgare Caryophyllaceae (Pink Family) Broadleaf
Clover, Strawberry Trifolium fragiferum Fabaceae (Pea or Bean Family) Broadleaf
Clover, White Trifolium repens Fabaceae (Pea or Bean Family) Broadleaf
Cocklebur, Common Xanthium strumarium Asteraceae (Sunflower Family) Broadleaf
Cudweed, Purple Gnaphalium purpureum Asteraceae (Sunflower Family) Broadleaf
Cudweeds Gnaphalium spp. Asteraceae (Sunflower Family) Broadleaf
Daisy, English Bellis perennis Asteraceae (Sunflower Family) Broadleaf
Dandelion Taraxacum officinale Asteraceae (Sunflower Family) Broadleaf
Dichondra, Kidney-weed Dichondra repens Convolvulaceae (Morningglory Family) Broadleaf
Dock, Curly Rumex crispus Polygonaceae (Buckwheat Family) Broadleaf
Dodder Cuscuta spp. Convolvulaceae (Morningglory Family) Broadleaf
Ducksalad Heteranthera limosa Pontedericaceae (Pickerelweed Family) Broadleaf
Fiddlenecks Amsinckia spp. Boraginaceae (Borage Family) Broadleaf
Fiddleneck, Coast Amsinckia menziesii var. intermedia Boraginaceae (Borage Family) Broadleaf
Filaree, Whitestem Erodium moschatum Geraniaceae (Geranium Family) Broadleaf
Filarees Erodium spp. Geraniaceae (Geranium Family) Broadleaf
Fleabane, Hairy Conyza bonariensis Asteraceae (Sunflower Family) Broadleaf
Flixweed Descurainia sophia Brassicaceae (Mustard Family) Broadleaf
Fluvellins Kickxia spuria, K. elatine Scrophulariaceae (Figwort Family) Broadleaf
Garlic, Wild Allium vineale Liliaceae (Lily Family) Broadleaf
Geranium, Cutleaf Geranium dissectum Geraniaceae (Geranium Family) Broadleaf
Goosefoot, Nettleleaf Chenopodium murale Chenopodiaceae (Goosefoot Family) Broadleaf
Groundcherries Physalis spp. Solanaceae (Nightshade Family) Broadleaf
Groundcherry, Tomatillo Physalis philadelphica Solanaceae (Nightshade Family) Broadleaf
Groundsel, Common Senecio vulgaris Asteraceae (Sunflower Family) Broadleaf
Healall Prunella vulgaris var. vulgaris Lamiaceae (Mint Family) Broadleaf
Hemlock, Poison Conium maculatum Apiaceae (Carrot Family) Broadleaf
Henbit Lamium amplexicaule Lamiaceae (Mint Family) Broadleaf
Horseweed Conyza canadensis Asteraceae (Sunflower Family) Broadleaf
Jimsonweed Datura stramonium Solanaceae (Nightshade Family) Broadleaf
Knapweed, Russian Acroptilon repens Asteraceae (Sunflower Family) Broadleaf
Knotweed, Common Polygonum arenastrum Polygonaceae (Buckwheat Family) Broadleaf
Kochia Kochia scoparia Chenopodiaceae (Goosefoot Family) Broadleaf
Ladysthumb Polygonum persicaria Chenopodiaceae (Goosefoot Family) Broadleaf
Lambsquarters, Common Chenopodium album Chenopodiaceae (Goosefoot Family) Broadleaf
Lettuce, Prickly Lactuca serriola Asteraceae (Sunflower Family) Broadleaf
Lettuce, Miner’s Claytonia perfoliata Portulacaceae (Purslane Family) Broadleaf
Madder, Field Sherardia arvensis Rubiaceae (Madder Family) Broadleaf
Mallow, Bristly Modiola caroliniana Malvaceae (Mallow Family) Broadleaf
Mallow, Little Malva parviflora Malvaceae (Mallow Family) Broadleaf
Medic, Black Medicago lupulina Fabaceae (Pea or Bean Family) Broadleaf
Milkthistle, Blessed Silybum marianum Asteraceae (Sunflower Family) Broadleaf
Mistletoes Phoradendron spp. Viscaceae (Mistletoe Family) Broadleaf
Morningglories Ipomoea spp. Convolvulaceae (Morningglory Family) Broadleaf
Morningglory, Japanese Ipomoea nil var. integriuscula also called Ipomoea hederacea var. integriuscula Convolvulaceae (Morningglory Family) Broadleaf
Morningglory, Tall Ipomoea purpurea Convolvulaceae (Morningglory Family) Broadleaf
Mullein, Turkey Croton setigerus Euphorbiaceae (Spurge Family) Broadleaf
Mustard, Tumble Sisymbrium altissimum Brassicaceae (Mustard Family) Broadleaf
Mustards Brassica spp. Brassicaceae (Mustard Family) Broadleaf
Naiads Najas spp. Hydrocharitaceae (Waterweed Family) Aquatic, Broadleaf
Nettle, Burning Urtica urens Urticaceae (Nettle Family) Broadleaf
Nightshade, Black Solanum nigrum Solanaceae (Nightshade Family) Broadleaf
Nightshade, Hairy Solanum physalifolium Solanaceae (Nightshade Family) Broadleaf
Nightshade, Silverleaf Solanum elaeagnifolium Solanaceae (Nightshade Family) Broadleaf
Oxtongue, Bristly Picris echioides Asteraceae (Sunflower Family) Broadleaf
Pearlwort, Birdseye Sagina procumbens Caryophyllaceae (Pink Family) Broadleaf
Pennywort Hydrocotyle sp. Apiaceae (Carrot Family) Broadleaf
Pepperweed, Perennial (Tall whitetop) Lepidium latifolium Brassicaceae (Mustard Family) Broadleaf
Pigweed, Redroot Amaranthus retroflexus Amaranthaceae (Pigweed Family) Broadleaf
Pigweeds Amaranthus spp. Amaranthaceae (Pigweed Family) Broadleaf
Pimpernel, Scarlet Anagallis arvensis Primulaceae (Primrose Family) Broadleaf
Pineappleweed Chamomilla suaveolens Asteraceae (Sunflower Family) Broadleaf
Plantain, Broadleaf Plantago major Plantaginaceae (Plantain Family) Broadleaf
Plantain, Buckhorn Plantago lanceolata Plantaginaceae (Plantain Family) Broadleaf
Poison-oak, Pacific Toxicodendron diversilobum Anacardiaceae (Sumac Family) Broadleaf
Puncturevine Tribulus terrestris Zygophyllaceae (Caltrop Family) Broadleaf
Purslane, Common Portulaca oleracea Portulacaceae (Purslane Family) Broadleaf
Radish, Wild Raphanus raphanistrum Brassicaceae (Mustard Family) Broadleaf
Redmaids Calandrinia ciliata Portulacaceae (Purslane Family) Broadleaf
Rocket, London Sisymbrium irio Brassicaceae (Mustard Family) Broadleaf
Redstems Ammannia spp. Lythraceae (Loosestrife Family) Broadleaf
Salsify, Common Tragopogon porrifolius Asteraceae (Sunflower Family) Broadleaf
Shepherd’s-purse Capsella bursa-pastoris Brassicaceae (Mustard Family) Broadleaf
Smartweed, Pale Polygonum lapathifolium Polygonaceae (Buckwheat Family) Broadleaf
Sorrel, red Rumex acetosella Polygonaceae (Buckwheat Family) Broadleaf
Sowthistle, Annual Sonchus oleraceus Asteraceae (Sunflower Family) Broadleaf
Sowthistles Sonchus spp. Asteraceae (Sunflower Family) Broadleaf
Speedwell, Persian Veronica persica Scrophulariaceae (Figwort Family) Broadleaf
Speedwell, thymeleaf Veronica serpyllifolia Scrophulariaceae (Figwort Family) Broadleaf
Spurge, Creeping Euphorbia serpens Euphorbiaceae (Spurge Family) Broadleaf
Spurge, Petty Euphorbia peplus Euphorbiaceae (Spurge Family) Broadleaf
Spurge, Spotted Euphorbia maculata Euphorbiaceae (Spurge Family) Broadleaf
Spurry, Corn Spergula arvensis Caryophyllaceae (Pink Family) Broadleaf
Starthistle, Yellow Centaurea solstitialis Asteraceae (Sunflower Family) Broadleaf
Stickleaf Mentzelia dispersa Loasaceae (Loasa Family) Broadleaf
Sunflowers Helianthus spp. Asteraceae (Sunflower Family) Broadleaf
Sweetclover, Yellow Melilotus officinalis Fabaceae (Pea or Bean Family) Broadleaf
Swinecress, Greater Lepidium coronopus Brassicaceae (Mustard Family) Broadleaf
Swinecress, Lesser Lepidium didymum Brassicaceae (Mustard Family) Broadleaf
Tarweeds Hemizonia spp. Asteraceae (Sunflower Family) Broadleaf
Thistle, Canada Cirsium arvense Asteraceae (Sunflower Family) Broadleaf
Thistle, Italian Carduus pycnocephalus Asteraceae (Sunflower Family) Broadleaf
Thistle, Russian Salsola tragus Chenopodiaceae (Goosefoot Family) Broadleaf
Thistle, Slenderflower Carduus tenuiflorus Asteraceae (Sunflower Family) Broadleaf
Thornapple, Sacred Datura wrightii Solanaceae (Nightshade Family) Broadleaf
Tobacco, Indian Nicotiana quadrivalis Solanaceae (Nightshade family) Broadleaf
Velvetleaf Abutilon theophrasti Malvaceae (Mallow Family) Broadleaf
Waterhyssops Bacopa spp. Scrophulariaceae (Figwort Family) Broadleaf
Waterplantain, Common Alisma plantago-aquatica Alismataceae (Waterplantain Family) Broadleaf
Wild Cucumber Marah spp. Cucurbitaceae (Squash Family) Broadleaf
Willowherbs Epilobium spp. Onagraceae (Evening Primrose Family) Broadleaf
Woodsorrel, Creeping Oxalis corniculata Oxalidaceae (Oxalis Family) Broadleaf
Yarrow, Common Achillea millefolium Asteraceae (Sunflower Family) Broadleaf

Grasses (Identification)—Top of page

Common Name Scientific Name Family Category
Barley, Foxtail Hordeum jubatum Poaceae (Grass Family) Grass
Barley, Hare Hordeum murinum ssp. leporinum Poaceae (Grass Family) Grass
Barnyardgrass Echinochloa crus-galli Poaceae (Grass Family) Grass
Bentgrasses Agrostis spp. Poaceae (Grass Family) Grass
Bermudagrass Cynodon dactylon Poaceae (Grass Family) Grass
Bluegrass, Annual Poa annua Poaceae (Grass Family) Grass
Bluegrass, Roughstalk Poa trivialis Poaceae (Grass Family) Grass
Brome, Ripgut Bromus diandrus Poaceae (Grass Family) Grass
Brome, Soft Bromus hordeaceus Poaceae (Grass Family) Grass
Bromegrasses Bromus spp. Poaceae (Grass Family) Grass
Canarygrass, Hood Phalaris paradoxa Poaceae (Grass Family) Grass
Canarygrass, Littleseed Phalaris minor Poaceae (Grass Family) Grass
Crabgrasses Digitaria spp. Poaceae (Grass Family) Grass
Crabgrass, Large Digitaria sanguinalis Poaceae (Grass Family) Grass
Crabgrass, Smooth Digitaria ischaemum Poaceae (Grass Family) Grass
Cupgrass, Southwestern Eriochloa acuminata Poaceae (Grass Family) Grass
Cupgrass, Prairie Eriochloa contracta Poaceae (Grass Family) Grass
Dallisgrass Paspalum dilatatum Poaceae (Grass Family) Grass
Fescue, Tall Festuca arundinacea Poaceae (Grass Family) Grass
Foxtail, Yellow Setaria pumila Poaceae (Grass Family) Grass
Foxtails Setaria spp. Poaceae (Grass Family) Grass
Goosegrass Eleusine indica Poaceae (Grass Family) Grass
Johnsongrass Sorghum halepense Poaceae (Grass Family) Grass
Junglerice Echinochloa colona Poaceae (Grass Family) Grass
Kikuyugrass Pennisetum clandestinum Poaceae (Grass Family) Grass
Knotgrass Paspalum distichum Poaceae (Grass Family) Grass
Lovegrass Eragrostis spp. Poaceae (Grass Family) Grass
Oat, Wild Avena fatua Poaceae (Grass Family) Grass
Orchardgrass Dactylis glomerata Poaceae (Grass Family) Grass
Panicum, Fall Panicum dichotomiflorum Poaceae (Grass Family) Grass
Polypogon, Rabbitfoot Polypogon monspeliensis Poaceae (Grass Family) Grass
Quackgrass Elytrigia repens Poaceae (Grass Family) Grass
Ryegrasses Lolium spp. Poaceae (Grass Family) Grass
Ryegrass, Italian Lolium multiflorum Poaceae (Grass Family) Grass
Sandbur, Longspine Cenchrus longispinus Poaceae (Grass Family) Grass
Shattercane Sorghum bicolor Poaceae (Grass family) Grass
Smutgrass Sporobolus indicus Poaceae (Grass Family) Grass
Sprangletop, Bearded Leptochloa fascicularis Poaceae (Grass Family) Grass
Velvetgrass, German Holcus mollis Poaceae (Grass Family) Grass
Wheat, Volunteer Triticum sp. Poaceae (Grass Family) Grass
Witchgrass Panicum capillare Poaceae (Grass Family) Grass

Sedges (Identification)—Top of page

Common Name Scientific Name Family Category
Bulrush, Ricefield Scirpus mucronatus Cyperaceae (Sedge Family) Sedge
Bulrush, River Scirpus fluviatilis Cyperaceae (Sedge Family) Sedge
Kyllinga, Green Kyllinga brevifolia Cyperaceae (Sedge Family) Sedge
Nutsedge Cyperus spp. Cyperaceae (Sedge Family) Sedge
Nutsedge, Purple Cyperus rotundus Cyperaceae (Sedge Family) Sedge
Nutsedge, Yellow Cyperus esculentus Cyperaceae (Sedge Family) Sedge
Sedge, Smallflower Umbrella Cyperus difformis Cyperaceae (Sedge Family) Sedge
Spikerush, Blunt Eleocharis obtusa Cyperaceae (Sedge Family) Sedge

More information

Statewide IPM Program, Agriculture and Natural Resources, University of California
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Links to photos and descriptions of common weeds of California.