Cosmos sulphureus - Cavanilles
Asteraceae (Composite Sunflower) Family
Yellow Cosmos is an introduced herbaceous annual in the Sunflower family (Asteraceae). It is native to Mexico, Central America, and northern South America. In Alabama it can be found statewide and is often planted in roadside wildflower plantings and as an ornamental. It persists or escapes to roadsides, vacant lots, and other ruderal habitats. It is an annual with a tap root. Stems are 2-6 feet in height, green in color, smooth or downy, and branched.
The leaves are opposite, petiolate, pinnately lobed, with ciliate margins.
The flowers are produced in heads. The heads are in corymbs. Each head is on a long stalk. Each head has 8-15 yellow ray flowers and 10-20 orange or yellow disc flowers.
The fruit is an awned achene; fusiform in shape with a long beak and barbed awns.
Like the orange flowered cosmos, the yellow flowered is also listed as an invasive species in some locations.