Psilocarphus brevissimus
Encyclopedia
Psilocarphus brevissimus is a species of flowering plant in the aster family
known by the common name short woollyheads. It is native to western North America from southwestern Canada, California
, to northwestern Mexico, as well as southern South America, where it grows in moist flats, such as vernal pool
s, and similar areas.
is a small, spherical flower head
which is a cluster of several tiny woolly disc flowers surrounded by leaflike bract
s but no phyllaries
. Each tiny flower is covered in a scale which is densely woolly with long white fibers, making the developing head appear cottony.
. This variety, the Delta woolly marbles (var. multiflorus) is an uncommon plant associated with vernal pools.
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 short woollyheads. It is native to western North America from southwestern Canada, 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 northwestern Mexico, as well as southern South America, where it grows in moist flats, such as vernal pool
Vernal pool
Vernal pools, also called vernal ponds or ephemeral pools, are temporary pools of water. They are usually devoid of fish, and thus allow the safe development of natal amphibian and insect species...
s, and similar areas.
Description
Psilocarphus brevissimus is a small, woolly annual herb growing just a few centimeters tall with a branching stem or multiple stems. The small, gray-green leaves are erect, pointing up parallel to the stem and sometimes appressed to it. The inflorescenceInflorescence
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 small, spherical flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
which is a cluster of several tiny woolly disc flowers surrounded by leaflike bract
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...
s but no 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...
. Each tiny flower is covered in a scale which is densely woolly with long white fibers, making the developing head appear cottony.
Varieties
There are two varieties of Psilocarphus brevissimus, with one limited to the Sacramento – San Joaquin River Delta and surrounding parts of the Central Valley of CaliforniaCalifornia
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...
. This variety, the Delta woolly marbles (var. multiflorus) is an uncommon plant associated with vernal pools.