''Pyrrocoma racemosa'' is a species of flowering plant in the family
Asteraceae
Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...
known by the common name clustered goldenweed.
It is native to the western United States, where it grows in many types of habitat. It is quite variable in
morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
*Morphology (archaeology), study of the shapes or forms of artifacts
*Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
, and there are several varieties which are sometimes hard to tell apart. In general, it is a perennial herb usually producing two or more mostly erect stems reaching maximum heights between 15 and 90 centimeters. The stems are reddish or brownish in color, leafy or not, and hairless to quite woolly. The longest leaves are located in tufts around the base of the stems. They are lance-shaped to oval, smooth-edged, wavy, or deeply spine-toothed, and may exceed 30 centimeters in length. Basal leaves are borne on woolly
petioles. Leaves located higher on the stem lack petioles and may clasp the stem at their bases. The
inflorescence
In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...
is a cluster of several
flower heads
A pseudanthium (; : pseudanthia) 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, composite flowers ...
lined with
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 o ...
which may be over a centimeter long and are hairy to hairless in texture. Each head contains many yellow disc florets and a fringe of several yellow ray florets. The fruit is an
achene
An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...
which may be over a centimeter long including its
pappus.
References
External links
Jepson Manual TreatmentUSDA Plants ProfileFlora of North AmericaPhoto gallery
racemosa
{{Astereae-stub