''Calycadenia villosa'' is an uncommon 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 dwarf western rosinweed. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to central

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 ...

, where it is known from a limited distribution in the Central Coast Ranges in

Monterey County Monterey County ( ), officially the County of Monterey, is a county located on the Pacific coast in the U.S. state of California. As of the 2020 census, its population was 439,035. The county's largest city and county seat is Salinas. Montere ...

and

San Luis Obispo County San Luis Obispo County (), officially the County of San Luis Obispo, is a county on the Central Coast of California. As of the 2020 census, the population was 282,424. The county seat is San Luis Obispo. Junípero Serra founded the Mission ...

, with a few populations in Santa Barbara and western Fresno Counties. There are perhaps 16 occurrences.The Nature Conservancy
/ref> ''Calycadenia villosa'' is an annual herb producing a very hairy erect stem approaching 40 centimeters (16 inches) in height. The leaves are linear (long and narrow) and up to 5 centimeters (2 inches) long. 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 made up of clusters of

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 ...

surrounded by gland-tipped

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s. Each flower head is a hairless bunch of small

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 one to four white to pink ray florets. Each ray floret has three lobes, the middle lobe being narrowest. 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 ...

; those developing from

s bear a pappus of scales.Flora of North America, ''Calycadenia villosa''
/ref>

References

External links

Jepson Manual TreatmentUSDA Plants ProfileCalphotos Photo gallery, University of California

villosa ''Villosa'' is a genus of freshwater mussels, aquatic bivalve molluscs in the family Unionidae The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simp ...

Flora of California Plants described in 1836 {{Asteroideae-stub