||Xanthium strumarium L.
||Erect, branched plant with speckled stems and prickly burs.
||Hypocotyls are purple towards the base. Cotyledons are thick, fleshy, lanceolate, and fairly large.
|True Leaves and Stem
||First true leaves are opposite, all others are alternate.
Leaf surface is rough with stiff hairs (feels like sandpaper). Leaves are
triangular shaped with three prominent veins and serrated margins. Stems
are branched, rough, and have purple speckling.
|Flower and Fruit
|| Flowers are enclosed within the bur.
Burs are elliptical to egg-shaped, brown, woody, and covered with prickles.
Two long beaks project from the tip of the bur. Each bur contains two seeds.
One seed has a short dormancy period, while the other can stay dormant for one
to several years.