Thalictrum occidentale
Encyclopedia
Thalictrum occidentale is a species of flowering plant in the buttercup family
known by the common name western meadow-rue. It is native to northwestern North America from Alaska
and western Canada to northern California
to Wyoming
and Colorado
, where it grows in shady habitat types such as forest understory and more open, moist habitat such as meadows. It is a perennial herb growing erect to a maximum height around a meter. It is hairless to lightly hairy and glandular. The leaves have compound blades divided into a few or many segments, often with three lobes, and are borne on long, slender petioles
. The inflorescence
is an upright or arching panicle
of flowers with leaflike, lobed bract
s often growing at the base. The species is dioecious
, with male and female flowers occurring on separate plants. The male flower has a bell-shaped calyx of four sepal
s in shades of greenish white or purple. From the calyx dangle many long, purple stamen
s tipped with large anthers. The female flower has a cluster of immature fruits tipped with styles
in shades of purple. A cluster has 4 to 9, at times up to 14, fruits.
Ranunculaceae
Ranunculaceae are a family of about 1700 species of flowering plants in about 60 genera, distributed worldwide....
known by the common name western meadow-rue. It is native to northwestern North America from Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
and western Canada to northern 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 Wyoming
Wyoming
Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...
and 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 shady habitat types such as forest understory and more open, moist habitat such as meadows. It is a perennial herb growing erect to a maximum height around a meter. It is hairless to lightly hairy and glandular. The leaves have compound blades divided into a few or many segments, often with three lobes, and are borne on long, slender 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 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 an upright or arching panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
of flowers with leaflike, lobed 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 often growing at the base. The species is dioecious
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, with male and female flowers occurring on separate plants. The male flower has a bell-shaped calyx of four 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 in shades of greenish white or purple. From the calyx dangle many long, purple stamen
Stamen
The stamen is the pollen producing reproductive organ of a flower...
s tipped with large anthers. The female flower has a cluster of immature fruits tipped with 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...
in shades of purple. A cluster has 4 to 9, at times up to 14, fruits.