Hemizonella minima
Encyclopedia
Hemizonella minima is a species of flowering plant in the aster family
known by the common name opposite-leaved tarweed.
It is native to western North America from British Columbia
and Montana
to southern California
, where it grows in many types of forest and scrub habitat from mountains to deserts.
It is a small annual herb producing a thin, fuzzy stem up to about 15 centimeters in maximum height. The pointed, hairy leaves are no more than 2.5 centimeters long. The inflorescence
produces one or more tiny flower heads
which are oblong or shaped like top
s on close inspection. Each is a few millimeters wide, enclosed in phyllaries
studded with stalked resin glands, and tipped with minute yellowish florets. The fruit is an achene
a few millimeters 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...
known by the common name opposite-leaved tarweed.
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...
and Montana
Montana
Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...
to southern 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...
, where it grows in many types of forest and scrub habitat from mountains to deserts.
It is a small annual herb producing a thin, fuzzy stem up to about 15 centimeters in maximum height. The pointed, hairy leaves are no more than 2.5 centimeters long. 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...
produces one or more tiny 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 oblong or shaped like top
Top
A top is a toy that can be spun on an axis, balancing on a point. This motion is produced in the most simple forms of top by twirling the stem using the fingers. More sophisticated tops are spun by by holding the axis firmly while pulling a string or twisting a stick or pushing an auger as shown...
s on close inspection. Each is a few millimeters wide, enclosed in 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...
studded with stalked resin glands, and tipped with minute yellowish 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 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...
.