''Calycadenia micrantha'' 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 small-flowered calycadenia. 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 ...

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 about 13 occurrences that are widely spread over several counties, including Napa, Siskiyou, Shasta, Mendocino,

Trinity The Christian doctrine of the Trinity (, from 'threefold') is the central dogma concerning the nature of God in most Christian churches, which defines one God existing in three coequal, coeternal, consubstantial divine persons: God the F ...

, and Monterey Counties, with several populations known in Lake County.Silversword Alliance: ''Calycadenia micrantha''
/ref>The Nature Conservancy
/ref> It was described to science as a species in 2004.Carr, R. L. and G. D. Carr. (2004). A new species of ''Calycadenia'' (Asteraceae) from north central California. ''Sida'' 21 259-265.
includes color photos Some specimens of the plant had previously been included within the description of its relative, ''

Calycadenia truncata ''Calycadenia truncata'' is a species of flowering plant in the family Asteraceae known by the common name Oregon western rosinweed. It is native to western North America. ''Calycadenia truncata'' is an annual herb producing an erect, reddish st ...

''.Flora of North America, ''Calycadenia micrantha''
/ref> The fact that it has been found in relatively far-flung locations suggests it could easily be present in other areas between them and, as a newly classified species, has simply not been reported yet. This annual plant produces a slender purplish stem 10 to 50 centimeters tall. The hairy leaves are 2 to 5 centimeters 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 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 small cluster of heads, each with 1 to 6 three-lobed yellow ray florets. Unlike other ''

Calycadenia ''Calycadenia'' is a genus of flowering plants in the family Asteraceae, known commonly as the western rosinweeds.

'' species, this plant is

self-compatible Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ...

, or able to fertilize itself.

References

External links

Jepson Manual Treatment
micrantha Flora of California Plants described in 2004 {{Asteroideae-stub