Artemisia ludoviciana
Encyclopedia
Artemisia ludoviciana is a species of sagebrush known by several common names, including silver wormwood, Louisiana wormwood, white sagebrush, and gray sagewort.
It is native to North America where it is widespread coast to coast, but many subspecies are found only in the western United States. This is a rhizomatous
perennial herb growing to heights between 30 centimeters and one meter. The stems bear linear leaves up to 11 centimeters long. The stems and foliage are covered in woolly gray or white hairs. The top of the stem is occupied by a narrow inflorescence
of many nodding flower heads
. Each small head is a cup of hairy phyllaries
surrounding a center of yellowish disc florets and is about half a centimeter wide. The fruit is a minute achene
. This plant was used by many Native American groups for a variety of medicinal, veterinary, and ceremonial purposes.
A. ludoviciana has become a popular garden plant, although it has a tendency to be aggressive in some gardens. The most commonly grown forms are the selections A. ludoviciana "Valerie Finnis" and "Silver Queen", the former named after British gardener and photographer Valerie Finnis
(1924–2006). Both these selections were awarded the Royal Horticultural Society's
Award of Garden Merit in 1993, and are hardy to USDA zone 4.
It is native to North America where it is widespread coast to coast, but many subspecies are found only in the western United States. This is a rhizomatous
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
perennial herb growing to heights between 30 centimeters and one meter. The stems bear linear leaves up to 11 centimeters long. The stems and foliage are covered in woolly gray or white hairs. The top of the stem is occupied by a narrow 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...
of many nodding flower heads
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
. Each small head is a cup of hairy 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...
surrounding a center of yellowish disc florets and is about half a centimeter wide. The fruit is a minute achene
Achene
An achene is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate and indehiscent...
. This plant was used by many Native American groups for a variety of medicinal, veterinary, and ceremonial purposes.
Subspecies
There are many subspecies, including:- A. l. ssp. albula - small-leafed subspecies native to the southwestern United States and northern Mexico
- A. l. ssp. candicans - native to western North America from British ColumbiaBritish ColumbiaBritish 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...
to northern CaliforniaCaliforniaCalifornia 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... - A. l. ssp. estesii - (Estes' artemisia) - endemic to OregonOregonOregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
- A. l. ssp. ludoviciana - the most widespread subspecies
Cultivation
Valerie Finnis
Valerie Finnis was a well known British photographer and gardener. She was born in Crowborough, Sussex, daughter of a naval officer, Steriker Finnis, and gardener Constance Finnis. She attended Hayes Court school in Kent and Downe House school in Berkshire...
(1924–2006). Both these selections were awarded the Royal Horticultural Society's
Royal Horticultural Society
The Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...
Award of Garden Merit in 1993, and are hardy to USDA zone 4.