''Perityle emoryi'' is a species of flowering plant in the aster family known by the common name Emory's rockdaisy. It is native to the

Southwestern United States The Southwestern United States, also known as the American Southwest or simply the Southwest, is a geographic and cultural region of the United States that generally includes Arizona, New Mexico, and adjacent portions of California, Colorado, Ne ...

, northwest Mexico, and the Baja California Peninsula. It is a common wildflower of the deserts, and can also be found in California coastal regions. It grows in many types of habitat, it tolerates disturbance, and it can become somewhat weedy. The plant is also known from

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

and it is an

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 there ...

in parts of

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

. Its distribution is apparently expanding.Flora of North America
/ref>

Description

''Perityle emoryi'', a

polyploid Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contain ...

plant, is quite variable genetically and in appearance. It is an annual herb growing 2 to 60 centimeters tall, its stem small, delicate, and simple, or thick, branching, and sprawling. It is usually hairy and glandular in texture. The alternately arranged leaves have blades of various shapes which are toothed or divided into lobes and borne on petioles. The

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 ...

is a single

flower head 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 ...

or an array of a few or many heads. The head is hemispherical to bell-shaped and generally no more than a centimeter wide. The head has a center of many golden disc florets and a fringe of 8 to 12 white ray florets each just a few millimeters long. The fruit is an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

, usually with a pappus at the tip.

References

External links

Jepson Manual Treatment = ''Perityle emoryi''USDA Plants Profile UC CalPhoto gallers gallery of ''Perityle emoryi''
Perityleae Flora of the Southwestern United States Flora of Baja California Flora of Baja California Sur Flora of the California desert regions Flora of Sonora Flora of Chile Flora of the Sonoran Deserts Natural history of the Mojave Desert Natural history of the Colorado Desert Taxa named by John Torrey Flora without expected TNC conservation status {{asteroideae-stub