''Psilocarphus brevissimus'' is a 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 names short woollyheads, woolly marbles, and woolly heads. The plant is native to western North America — from southwestern Canada, through

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 ...

, to northwestern Mexico, as well as in southern South America. It grows in moist flats such as

vernal pool Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe ...

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

s, and similar areas. It is found from sea level to .

Description

''Psilocarphus brevissimus'' is a small, woolly annual herb growing just a few centimeters tall with a branching stem or multiple stems. The small, gray-green leaves are erect, pointing up parallel to the stem and sometimes appressed to it. 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 small, spherical

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 ...

which is a cluster of several tiny woolly disc flowers surrounded by leaflike

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 but no

phyllaries In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one or ...

. Each tiny flower is covered in a scale which is densely woolly with long white fibers, making the developing head appear cottony.

Varieties

There are two varieties of ''Psilocarphus brevissimus'': *''Psilocarphus brevissimus'' var. ''brevissimus'' — formerly ''Psilocarphus globiferus'' *''Psilocarphus brevissimus'' var. ''multiflorus'' (Delta woolly marbles) — limited to the

Sacramento – San Joaquin River Delta ) , image_map = Sacramento County California Incorporated and Unincorporated areas Sacramento Highlighted.svg , mapsize = 250x200px , map_caption = Location within Sacramento C ...

and surrounding parts of the Central Valley of California. This is an uncommon plant associated with vernal pools.Jepson Manual Treatment: var. ''multiflorus''
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References

External links

*
Jepson Manual Treatment — ''Psilocarphus brevissimus''USDA Plants ProfileFlora of North America''Psilocarphus brevissimus'' — U.C. Photo gallery
{{Taxonbar, from=Q7255813 Gnaphalieae Flora of the West Coast of the United States Flora of Northwestern Mexico Flora of Western Canada Flora of California Flora of southern South America Flora of the Sierra Nevada (United States) Natural history of the California Coast Ranges Natural history of the Central Valley (California) Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Flora without expected TNC conservation status