''Amaranthus watsonii'' is a species of

amaranth ''Amaranthus'' is a cosmopolitan distribution, cosmopolitan group of more than 50 species which make up the genus of annual plant, annual or short-lived perennial plants collectively known as amaranths. Some names include "prostrate pigweed" an ...

known by the common name Watson's amaranth. It is native to the southwestern United States and northern Mexico, where it grows in sandy places such as deserts and beaches, and disturbed areas. It is also known as a rare

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

in parts of Europe. This is an erect annual herb producing a glandular hairy stem to a maximum height of about a meter. The leaves are generally oval-shaped and up to 8 centimeters long, with a

petiole Petiole may refer to: *Petiole (botany), the stalk of a leaf, attaching the blade to the stem *Petiole (insect anatomy) In entomology, petiole is the technical term for the narrow waist of some hymenopteran insects, especially ants, bees, and ...

of up to 9 centimeters. The species is

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, with male and female individuals producing different types of flowers. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is a long spike cluster of flowers interspersed with spiny green glandular

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

s. The fruit is a smooth capsule about 2 millimeters long that snaps in half to reveal a small shiny reddish black seed.

References

External links

Jepson Manual TreatmentPhoto gallery
watsonii Flora of the Southwestern United States Flora of Mexico Dioecious plants {{Amaranthaceae-stub