Senecio hydrophilus
Encyclopedia
Senecio hydrophilus is a species of flowering plant in the aster family
known by the common names water ragwort and alkali marsh groundsel. It is native to western North America from British Columbia
to California
to Colorado
, where it grows in swampy places such as marsh
es. It can grow in standing water, including alkaline and salty water. It is a biennial or perennial herb producing a single erect stem or a cluster of a few stems which may exceed one meter in maximum height, at times approaching two meters. The stem is hollow, waxy in texture, and often pale green in color, and it emerges from a small caudex
. The thick leaves are lance-shaped to oval with smooth or toothed edges, the blades up to 20 centimeters long and borne on petioles
. Smaller leaves occur farther up the stem. The inflorescence
is one or more large, spreading clusters of many flower head
s. They contain many yellowish disc florets at the center and sometimes have small yellow ray florets as well.
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 names water ragwort and alkali marsh groundsel. It is native to western North America from 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...
to Colorado
Colorado
Colorado is a U.S. state that encompasses much of the Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains...
, where it grows in swampy places such as marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es. It can grow in standing water, including alkaline and salty water. It is a biennial or perennial herb producing a single erect stem or a cluster of a few stems which may exceed one meter in maximum height, at times approaching two meters. The stem is hollow, waxy in texture, and often pale green in color, and it emerges from a small caudex
Caudex
A caudex is a form of stem morphology appearing as a thickened, short, perennial stem that is either underground or near ground level . It may be swollen for the purpose of water storage, especially in xerophytes...
. The thick leaves are lance-shaped to oval with smooth or toothed edges, the blades up to 20 centimeters long and borne on 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...
. Smaller leaves occur farther up the stem. 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 one or more large, spreading clusters of many flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
s. They contain many yellowish disc florets at the center and sometimes have small yellow ray florets as well.