''Helianthus petiolaris'' is a North American plant species 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 ...

, commonly known as the prairie sunflower or lesser sunflower. Naturalist and botanist

Thomas Nuttall Thomas Nuttall (5 January 1786 – 10 September 1859) was an England, English botany, botanist and zoologist who lived and worked in America from 1808 until 1841. Nuttall was born in the village of Long Preston, near Settle, North Yorkshire, S ...

was the first to describe the prairie sunflower in 1821. The word ''petiolaris'' in Latin means, “having a petiole”. The species originated in Western United States, but has since expanded east. The prairie sunflower is sometimes considered a weed.

Distribution

''Helianthus petiolaris'' originated in the dry prairies of

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

Texas Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...

, the

Dakotas The Dakotas is a collective term for the U.S. states of North Dakota and South Dakota. It has been used historically to describe the Dakota Territory, and is still used for the collective heritage, culture, geography, fauna, sociology, econom ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, and other states in Western and Central United States. It has since expanded its distribution to throughout the Eastern United States and into central and western Canada. It is now the most widely distributed species of sunflower besides ''H. annuus''.

Habitat and ecology

Prairie sunflowers are commonly found growing in sandy areas. They can also be found in heavy clay soil and in dry prairies. They are unable to grow in shady areas; they need to be in direct sunlight. Prairie sunflowers require dry to moist soil. This species of sunflower is an annual flower, blooming between June and September.

Morphology

Prairie sunflower is a

taproot A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...

ed annual. It grows up to 4 ft (120 cm) tall. The leaves appear alternate and the flowers have a close resemblance to the traditional sunflower. The flowers are

hermaphrodite In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many Taxonomy (biology), taxonomic groups of animals (mostly invertebrate ...

s, which means the flowers contain both male and female parts. The stem of the flower is erect and hairy. The leaves are alternate, have a lanceolate shape, are rough in texture, are bluish-green in color, and have a length between 2 and 5 in.

Flowers

''Helianthus petiolaris'' has flower heads reminiscent of those of a common sunflower, ''H. annuus''. The fruits of the flowers are known as

achenes 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 ...

. The

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 ...

contains 10-30 yellow

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 ...

, surrounding 50-100 dark red-brown

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, and green, lanceolate phyllaries (bracts). The center of the flower has hints of white due to the presence of white hairs on the chaff. The flowers attract butterflies and bees for pollination.

Food

The seeds in the plant are edible and can be ground up into an oily meal or into a butter.

Medicinal

Powdered leaves of the prairie sunflower are said to work well with the healing of sores and swellings. ;Varieties *''Helianthus petiolaris'' var. ''canescens'' A.Gray -

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 ...

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ker ...

, Chihuahua *''Helianthus petiolaris'' var. var. ''fallax'' (Heiser) B.L.Turner - Arizona,

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

, Nevada,

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

*''Helianthus petiolaris'' var. var. ''petiolaris'' - most of species range

References

{{Taxonbar, from=Q5704886 petiolaris Plants described in 1821 Flora of North America