Chaenactis artemisiifolia
Encyclopedia
Chaenactis artemisiifolia, with the common name White pincushion, is a species of flowering plant in the daisy family
. It is native to the coastal Peninsular Ranges
of Southern California
and Baja California
, in the chaparral and woodlands
.
The stem branches about midway up and bears several flower heads
in a wide open inflorescence
. Each head is a hairy hemispheric cup of sharp-tipped phyllaries
which can be up to a centimeter long. The flower heads are discoid, containing only disc florets, but some of them are flat enough to resemble ray florets or petals. The florets are white to pink. The anthers
and curly styles
protrude far from each floret, making the flower head look like a pincushion
. The fruit is a compressed achene
about half a centimeter long with no 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...
. It is native to the coastal Peninsular Ranges
Peninsular Ranges
The Peninsular Ranges are a group of mountain ranges, in the Pacific Coast Ranges, which stretch from southern California in the United States to the southern tip of Mexico's Baja California peninsula; they are part of the North American Coast Ranges that run along the Pacific coast from Alaska...
of Southern California
Southern California
Southern California is a megaregion, or megapolitan area, in the southern area of the U.S. state of California. Large urban areas include Greater Los Angeles and Greater San Diego. The urban area stretches along the coast from Ventura through the Southland and Inland Empire to San Diego...
and Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, in the chaparral and woodlands
California chaparral and woodlands
The California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
.
Description
The Chaenactis artemisiifolia is a robust annual herb producing an erect stem occasionally as tall as two meters-6 feet but usually under one meter-3 feet in height. There is a basal rosette of leaves and sparse leaves along the stem. The leaves are up to about 15 centimeters or more in length and they are divided into many lobes which are further subdivided into smaller, lacy lobes. The leaves and stem are lightly woolly; older plants have thinner coats of hair.The stem branches about midway up and bears 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....
in a wide open 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...
. Each head is a hairy hemispheric cup of sharp-tipped 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 can be up to a centimeter long. The flower heads are discoid, containing only disc florets, but some of them are flat enough to resemble ray florets or petals. The florets are white to pink. The anthers
Stamen
The stamen is the pollen producing reproductive organ of a flower...
and curly styles
Gynoecium
Gynoecium is most commonly used as a collective term for all carpels in a flower. A carpel is the ovule and seed producing reproductive organ in flowering plants. Carpels are derived from ovule-bearing leaves which evolved to form a closed structure containing the ovules...
protrude far from each floret, making the flower head look like a pincushion
Pincushion
A pincushion is a small cushion, typically 3–5 cm across, which is used in sewing to store pins or needles with their heads protruding so as to take hold of them easily, collect them, and keep them organized....
. The fruit is a compressed achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
about half a centimeter long with no 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...
.
See also
- California chaparral and woodlandsCalifornia chaparral and woodlandsThe California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
- California coastal sage and chaparral ecoregionCalifornia coastal sage and chaparral ecoregionThe California coastal sage and chaparral, a sub-ecoregion of the California chaparral and woodlands ecoregion, is found in southwestern California and northwestern Baja California in Mexico.-Location:...
- California montane chaparral and woodlandsCalifornia montane chaparral and woodlandsThe California montane chaparral and woodlands ecoregion covers , including the mountains of the Transverse, Peninsular, and Santa Lucia Ranges of California. It is part of the Mediterranean forests, woodlands, and scrub biome, with cool, wet winters and hot, dry summers...