Ageratina occidentalis
Encyclopedia
Ageratina occidentalis is a species
of flowering plant
in the daisy family
known by the common name western snakeroot or western eupatorium. It is native to the western United States where it grows in several types of habitat
. This is a rhizomatous
perennial herb growing fuzzy green or purple stems to a maximum height near 70 centimeters. The glandular leaves are triangular in shape with serrated edges. The inflorescence
is a dense cluster of fuzzy flower heads
containing long, protruding disc florets in shades of white, pink, and blue. There are no ray florets. The fruit is an achene
a few millimeters long with a rough, bristly pappus
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of flowering plant
Flowering plant
The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
in the daisy family
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 western snakeroot or western eupatorium. It is native to the western United States where it grows in several types of habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...
. This is a rhizomatous
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
perennial herb growing fuzzy green or purple stems to a maximum height near 70 centimeters. The glandular leaves are triangular in shape with serrated edges. 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 dense cluster of fuzzy flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
containing long, protruding disc florets in shades of white, pink, and blue. There are no 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...
a few millimeters long with a rough, bristly 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...
.