Cirsium remotifolium
Encyclopedia
Cirsium remotifolium is a species of thistle
known by the common name fewleaf thistle. It is native to the western United States, including the Pacific Coast and possibly as far east as the Rocky Mountains
, depending on which populations are treated as part of the species. It is sometimes part of the serpentine soil
s flora. This native thistle is a perennial herb growing up to about 1.5 meters tall. The leaves are borne on spiny petioles
and are toothed or lobed, the lowest leaves at the base of the stem reaching 50 centimeters in length. The inflorescence
is made up of clustered flower heads
which are lined with spiny phyllaries
. The head is filled with white or purple flowers up to 2.5 centimeters long. The fruit is an achene
a few millimeters long topped with a pappus
up to about 2 centimeters in length.
Cirsium
Cirsium is a genus of perennial and biennial flowering plants in the Asteraceae, one of several genera known commonly as thistles. They are more accurately known as Plume thistles. These differ from other thistle genera in having feathered hairs to their achenes...
known by the common name fewleaf thistle. It is native to the western United States, including the Pacific Coast and possibly as far east as the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
, depending on which populations are treated as part of the species. It is sometimes part of the serpentine soil
Serpentine soil
A serpentine soil is derived from ultramafic rocks, in particular serpentinite, a rock formed by the hydration and metamorphic transformation of ultramafic rock from the Earth's mantle....
s flora. This native thistle is a perennial herb growing up to about 1.5 meters tall. The leaves are borne on spiny 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...
and are toothed or lobed, the lowest leaves at the base of the stem reaching 50 centimeters in length. 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 made up of clustered flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
which are lined with spiny 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...
. The head is filled with white or purple flowers up to 2.5 centimeters long. 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 topped with a 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...
up to about 2 centimeters in length.