Trifolium microcephalum
Encyclopedia
Trifolium microcephalum is a species of clover
known by the common name smallhead clover. It is native to western North America from southern Alaska
and British Columbia
to California
and Arizona
, where it occurs in many types of habitat, becoming common to abundant in some regions. It can grow in disturbed habitat and become a casual roadside weed
. It is an annual herb taking a decumbent or erect form. It is coated in hairs. The leaves are made up of oval leaflets with notched tips, each measuring up to 2 centimeters long, and bristle-tipped stipule
s. The inflorescence
is a head of flowers borne in a bowl-like involucre of wide, hairy bract
s. The head is not more than a centimeter wide. Each flower has a calyx of sepal
s with lobes narrowing into hairy bristles. The flower corolla is pinkish or purplish and measures 4 to 7 millimeters in length.
Clover
Clover , or trefoil, is a genus of about 300 species of plants in the leguminous pea family Fabaceae. The genus has a cosmopolitan distribution; the highest diversity is found in the temperate Northern Hemisphere, but many species also occur in South America and Africa, including at high altitudes...
known by the common name smallhead clover. It is native to western North America from southern Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, where it occurs in many types of habitat, becoming common to abundant in some regions. It can grow in disturbed habitat and become a casual roadside weed
Weed
A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
. It is an annual herb taking a decumbent or erect form. It is coated in hairs. The leaves are made up of oval leaflets with notched tips, each measuring up to 2 centimeters long, and bristle-tipped stipule
Stipule
In botany, stipule is a term coined by Linnaeus which refers to outgrowths borne on either side of the base of a leafstalk...
s. The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a head of flowers borne in a bowl-like involucre of wide, hairy bract
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 often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
s. The head is not more than a centimeter wide. Each flower has a calyx of sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s with lobes narrowing into hairy bristles. The flower corolla is pinkish or purplish and measures 4 to 7 millimeters in length.