Seed ID

Amaranthaceae, Asteraceae, and Chenopodiaceae

Plant Photo Scientific Name Common Name and Description Seed Photo
Pigweed Plant Amaranthus spinosus Common Name: Spiny Amaranth or Pigweed
Leaves: Alternate, ovate-lanceolate to ovate, glabrous to sparingly pubescent (covered with short hairs - downy), 3-10 cm long
Flowers: Male and female flowers, occasional flowers perfect, spikes numerous, 5-15 cm long
Fruit: Black, nearly round, 0.7-1 mm in diameter
Habitat: In waste ground, sandy loamy soil
Range: East third of Texas, west to Dallas, Travis and Cameron counties
Group: Dicot
Family: Amaranthaceae
Growth Habit: Forb/Herb - weedy, long (to 4 dm taproot), stems stout and succulent, erect, branched, 3-12 dm tall
Duration: Annual
U.S. Nativity: Probably tropical in origin (Correll and Johnston); Native (USDA)
Pigweed Seed
Giant Ragweed Ambrosia trifida Common Name: Giant Ragweed
Leaves: Alternate or opposite at the lower nodes, in some species opposite nearly throughout, entire or palmately lobed or (usually) pinnately lobed or dissected
Flowers: Ray flowers absent, lacking pappus and corolla, phyllaries fused about flowers to form a hard indehiscent nutlike receptacle
Fruit: Brown achene ~4 mm
Habitat: Abundant in seasonally moist stream bottoms and overflow areas
Range: Throughout the eastern and northern halves of Texas; the midwest, and the central United States to the Rocky Mountains and from southern Canada to northern Mexico
Group: Dicot
Family: Asteraceae
Growth Habit: Subshrub/Forb/Herb - tall erect annual taprooted herb 1-3 meters tall, stem angled, striate and scabrous
Duration: Annual
U.S. Nativity: Native
Giant Ragweed
Sunflower Helianthus annuus Common Name: Sunflower
Leaves: Leaves always opposite at least at the base of the stems and usually alternate above, ovate, obtuse or less commonly acute and coarse-textured
Flowers: Disc 3-5 cm across, rays 21-35 are 3-5 cm long and 10-15 mm broad
Fruit: A dark achene with white stripes 4-7 mm
Habitat: Fields, borders, waste places and gardens
Range: Rare in northeast Texas; found in the east and central United States and south Canada
Group: Dicot
Family: Asteraceae
Growth Habit: Forb/Herb - taprooted annual, stems 5-25 dm tall
Duration: Annual
U.S. Nativity: Native
Iva annua Iva annua Common Name: Annual Marshelder or Sumpweed
Leaves: Alternate or opposite 3-12 cm long, ovate or becoming lanceolate upward
Flowers: Staminate flowers 9-17, corolla about 2.5 mm long, pistillate flowers 3-5, corollas about 1.5 mm long
Fruit: Achenes 2-4.5 mm long, brown, broadly ovate, lenticular
Habitat: Fields, borders, waste places and gardens
Range: East half of Texas, west to Wheeler, Taylor, Travis, DeWitt and Hidalgo counties; most of the eastern United States, west to Nebraska, Kansas, Oklahoma and Texas
Group: Dicot
Family: Asteraceae
Growth Habit: Forb/Herb - taprooted 4-20 dm tall
Duration: Annual
U.S. Nativity: Native
Goosefoot Chenopodium album Common Name: Pigweed, Goosefoot, Lamb's-Quarters, or Wild Spinach
Leaves: Oval-rhombic, rarely ovate or lanceolate, 2.5-8 cm long, usually conspicuously longer than broad, obtuse or rounded and apiculate at the apex, often shallowly 3-lobed, pale-green and glabrate above, densely farinose beneath
Flowers: Flowers in large glomerules, terminal stout erect or ascending paniculate spikes to 3 dm long, grayish-green
Fruit: Black, 1.1-1.5 mm broad, nearly smooth to minutely pitted
Habitat: Fields, fencerows and waste places.
Range: Newfoundland to Florida, west to Yukon and British Columbia, south to Mexico and South America, also in North Africa
Group: Dicot
Family: Chenopodiaceae
Growth Habit: Forb/Herb - pale-green, sometimes turning reddish, 6-30 dm tall
Duration: Annual
U.S. Nativity: Eurasian (Correll and Johnston); Native and Introduced (USDA)


Thumbnails of the plant photos were copied from those photos produced by the Texas A&M Bioinformatics Working Group which can be found at the Vascular Plant Image Gallery in the Flowering Gateway. When clicking on the thumbnail your are taken to their originals.

Thumbnails and enlargements of seed photos are from my own personal collection.

Some plant information has been taken from these sources:

  • Manual of the Vascular Plants of Texas, Donovan S. Correll and Marshall C. Johnston, University of Texas at Dallas, 1979.

  • USDA, NRCS. 2001. The PLANTS Database, Version 3.1. National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

  • Trees, Shrubs, and Woody Vines of the Southwest: A guide for the states of Arkansas, Louisiana, New Mexico, Oklahoma, and Texas, Robert A. Vines, University of Texas Press, 1994.