Pyrrocoma racemosa
Encyclopedia
Pyrrocoma racemosa is a species of flowering plant in the aster family
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
, 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
is a cluster of several flower heads
lined with phyllaries
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
which may be over a centimeter long including its pappus
.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
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 (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
, 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
Petiole (botany)
In botany, the petiole is the stalk attaching the leaf blade to the stem. The petiole usually has the same internal structure as the stem. Outgrowths appearing on each side of the petiole are called stipules. Leaves lacking a petiole are called sessile, or clasping when they partly surround the...
. Leaves located higher on the stem lack petioles and may clasp the stem at their bases. 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 cluster of several flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
lined with phyllaries
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...
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
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
which may be over a centimeter long including its pappus
Pappus (flower structure)
The pappus is the modified calyx, the part of an individual disk, ray or ligule floret surrounding the base of the corolla, in flower heads of the plant family Asteraceae. The pappus may be composed of bristles , awns, scales, or may be absent. In some species, the pappus is too small to see...
.