''Helenium arizonicum'' is a North American

perennial plant A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

in the Sunflower Family, commonly known as Arizona sneezeweed. It is native only 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 southwestern United States, having been found only in four counties in that state:

Apache The Apache () are a group of culturally related Native American tribes in the Southwestern United States, which include the Chiricahua, Jicarilla, Lipan, Mescalero, Mimbreño, Ndendahe (Bedonkohe or Mogollon and Nednhi or Carrizaleño an ...

Navajo The Navajo (; British English: Navaho; nv, Diné or ') are a Native American people of the Southwestern United States. With more than 399,494 enrolled tribal members , the Navajo Nation is the largest federally recognized tribe in the United ...

, Gila, and Coconino.SEINet, Southwestern Biodiversity, Arizona Chapter, ''Helenium arizonicum'' Blake
/ref> ''Helenium arizonicum'' is an annual herb up to 70 cm (28 inches) tall. One plant can produce as many as 25

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 ...

, in branching arrays. The head is very nearly spherical or egg-shaped, nearly covered with as many as 700

disc floret 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 ...

s, each floret yellow near the base but purple towards the tip. There are also 12-18

ray florets 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 ...

, yellow, sometimes with purple streaks. The species grows along the edges of wet places in pine forests.Flora of North America, ''Helenium arizonicum'' S. F. Blake, 1937. Arizona sneezeweed
/ref>

References

Flora of Arizona Plants described in 1937 arizonicum {{Helenieae-stub