Clarkia australis
Encyclopedia
Clarkia australis is a species of flowering plant in the evening primrose family
known by the common name Small's southern clarkia. It is endemic to California
, where it grows in the forests of the central Sierra Nevada. It is an uncommon species threatened by such forest activities as logging
. This annual herb produces a slender, erect stem approaching a meter in height. The leaves are widely linear in shape and borne on short petioles
. The top of the stem is occupied by the tall inflorescence
, which bears hanging buds that open from the lowest upward, so that there are several closed buds above open flowers. The sepal
s do not remain fused as the flower opens. The petals are diamond-shaped and sometimes lobed and curling at the tip. They are mottled or spotted lavender, purple, and reddish in color, and each is up to 1.5 centimeters long. There are 8 long stamen
s tipped with large anthers bearing blue-gray pollen. The stigma
protrudes past the anthers.
This species of Clarkia
is very closely related to Clarkia virgata
, and it has been suggested that it is not actually a separate species, but hybridization studies have demonstrated that there has been sufficient reproductive isolation
to cause hybrid incompatibility between the two plants, confirming that they should be treated as separate species.
Onagraceae
Onagraceae, also known as the Willowherb family or Evening Primrose family, are a family of flowering plants. The family includes about 640-650 species of herbs, shrubs, and trees in 20-24 genera...
known by the common name Small's southern clarkia. It is endemic 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...
, where it grows in the forests of the central Sierra Nevada. It is an uncommon species threatened by such forest activities as logging
Logging
Logging is the cutting, skidding, on-site processing, and loading of trees or logs onto trucks.In forestry, the term logging is sometimes used in a narrow sense concerning the logistics of moving wood from the stump to somewhere outside the forest, usually a sawmill or a lumber yard...
. This annual herb produces a slender, erect stem approaching a meter in height. The leaves are widely linear in shape and borne on short 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...
. The top of the stem is occupied by the tall 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...
, which bears hanging buds that open from the lowest upward, so that there are several closed buds above open flowers. The sepal
Sepal
A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...
s do not remain fused as the flower opens. The petals are diamond-shaped and sometimes lobed and curling at the tip. They are mottled or spotted lavender, purple, and reddish in color, and each is up to 1.5 centimeters long. There are 8 long stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s tipped with large anthers bearing blue-gray pollen. The stigma
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...
protrudes past the anthers.
This species of Clarkia
Clarkia
Clarkia is a genus within the flowering plant family Onagraceae. Over 40 species are currently classified in Clarkia; almost all are native to western North America, though one species is native to South America....
is very closely related to Clarkia virgata
Clarkia virgata
Clarkia virgata is a species of flowering plant in the evening primrose family known by the common name Sierra clarkia. It is endemic to California, where it is known from the forests and woodlands of the Sierra Nevada.-Description:...
, and it has been suggested that it is not actually a separate species, but hybridization studies have demonstrated that there has been sufficient reproductive isolation
Reproductive isolation
The mechanisms of reproductive isolation or hybridization barriers are a collection of mechanisms, behaviors and physiological processes that prevent the members of two different species that cross or mate from producing offspring, or which ensure that any offspring that may be produced is not...
to cause hybrid incompatibility between the two plants, confirming that they should be treated as separate species.