''Gutierrezia arizonica'' is a North American species of flowering plant in the family

Asteraceae The family Asteraceae, alternatively Compositae, consists of over 32,000 known species of flowering plants in over 1,900 genera within the order Asterales. Commonly referred to as the aster, daisy, composite, or sunflower family, Compositae w ...

known by the common name Arizona snakeweed. It is native to

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

in the United States and

Sonora Sonora (), officially Estado Libre y Soberano de Sonora ( en, Free and Sovereign State of Sonora), is one of the 31 states which, along with Mexico City, comprise the Administrative divisions of Mexico, Federal Entities of Mexico. The state is d ...

in northwestern Mexico.SEINet, Southwestern Biodiversity, Arizona Chapter
photos, description, distribution map ''Gutierrezia arizonica'' is an annual herb up to 30 cm (1 foot) in height. At the end of each branch there is an

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

of one or a few small

flower heads A pseudanthium (Greek for "false flower"; ) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, compos ...

just a few millimeters wide. The head contains 16-40 disc florets with 8-15 white ray florets around the edge.Flora of North America, ''Gutierrezia arizonica'' (A. Gray) M. A. Lane, 1980. Arizona snakeweed
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References

arizonica Flora of Arizona Flora of Sonora Flora of the Sonoran Deserts Plants described in 1880 Taxa named by Asa Gray {{Astereae-stub