Amaranthus spinosus

Common Name: 
spiny amaranth, spiny pigweed
Scientific Name: 
Amaranthus spinosus
Family Name: 
Amaranthaceae - Amaranth Family
Identification Notes
Life Cycle
introduced annual, reproducing by seed
Stems
upright, branched, smooth, reddish, pair of sharp spines at nodes
Growth Habit of Spiny Amaranth
Growth Habit of Spiny Amaranth
Leaves
alternate, oval, entire, smooth, long petiole, often water-marked
Leaves of Spiny Amaranth
Leaves of Spiny Amaranth
Flowers
terminal spikes - green, small, mostly staminate (male); axillary clusters – green, small, mostly pistillate (female)
Female Flower Clusters of Spiny Amaranth
Male Flower Clusters of Spiny Amaranth