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Plants of the Eloise Butler Wildflower Garden

The oldest public wildflower garden in the United States

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Common Name
White Sage (Prairie Sage, Silver Wormwood, Silver Sage, Western Mugwort, Louisiana Sage-wort)

 

Scientific Name
Artemisia ludoviciana Nutt. subsp. ludoviciana

 

Plant Family
Aster (Asteraceae, tribe Anthemideae)

Garden Location
Upland

 

Prime Season
Late Summer to Autumn

 

 

White Sage is a native perennial forb growing 1 to 3 feet high on an erect stem that is covered with dense matted white to grayish hair. There may be some branching in the upper section.

Leaves are alternate; the stalked lower leaves are up to 11 cm long, and have a narrow lance shape with a few coarse teeth toward the tip which can be also considered as small lobes. Upper leaves are more linear without lobes or teeth, usually stalkless, and are also covered with grayish-white hairs, especially on the lower surface, hence the common name of White Sage or Silver Sage. The foliage is aromatic due to the leaf hairs of most Artemisias being multi-celled and containing aromatic terpenoids.

The floral array is a dense array of panicles or raceme-like arrays of small flower heads - unusually small for the Aster family. These arrays populate the upper part of the stem and are quite narrow - only 1 to 6 cm in diamter. The flower heads are normally erect when in flower and seed.

Flowers: The flower head itself is of ovoid shape, with the head less than 4 mm in diameter, with a number of short gray-green phyllaries in several series around the base. These are also dense with matted hairy filaments. Being in the Aster family the flower would normally composed of both ray and disc florets. Artemisia usually has only disc florets but of two types. The outer florets number 5 to 12 and are pistillate (female) only. The inner disc florets number 6 to 30 and are bisexual and fertile. These have funnel shape corollas, pale yellow in color.

Seed: The fertile florets produce a brown dry ellipsoid seed called a cypsela, 1/2 mm long, that does not have any attached pappus and is wind dispersed. Flowers are wind pollinated.

 

Habitat: It is a plant of the open dryer areas, growing well when in full sun and spreading by an underground rhizomatous root system. The root system can be aggressive in spreading with the fibrous part of the roots often forming a dense mat below soil level. However, the species is not particularly agressive and can be crowded out by more aggressive grasses and forbs.

Winter interest: They can provide good winter interest to the garden as they survive the winter quite well, with the mature seed heads providing a contrasting color.

Names: The genus Artemisia is named after Artemisia, Queen of Anatolia who was named after the Greek goddess of the hunt, Artemis. The species name ludoviciana, refers to Louisiana, the state that was named after King Louis X of France. The plant was first typed there and hence one of the alternate common names of Lousisana Sage-wort. The author name of the plant classification, ‘Nutt.’, refers to Thomas Nuttall (1786-1859) English botanist who lived and worked in America from 1808 to 1841. On his many expeditions he collected many species that had been originally collected by Louis and Clark but lost by them on their return journey.

Comparisons: As explained at the bottom page section about the extensive breath of this genus - 350 to 500 estimated - and 50 alone described in Flora of North America (Ref. #W7), one would be advised to consult a key. All have very small flowers where the differences are difficult to examine. There are six subspecies alone of Artemisia ludoviciana recognized by Flora of North America. See notes about those at the bottom section of this page.

See bottom of page for notes on the Garden's planting history, distribution in Minnesota and North America, lore and other references.

Prairie Sage Prairie Sage

Abovde: 1st photo - The flower heads appear in narrow stalked panicles or spike-like racemes in the top half of the plant, interspersed between the stem leaves. 2nd photo - Drying flower heads of mid to late September ready to produce seed.

Below: 1st photo - The stem and undersurface of the leaves are covered with dense silvery-white hairs. 2nd photo - Flower heads in late summer before opening. 3rd photo - The plant as it appears the following spring, still upright, having provide good winter interest.

Stem Prairie Sage Prairie Sage

Below: The aromatic leaves of Prairie Sage are quite hairy, especially the underside (2nd photo). Leaves on the mid and lower stem have small teeth on the upper margins.

leaf upper surface leaf underside

Notes:

Notes: Eloise Butler first introduced White Sage into the Garden on Oct. 16, 1909 with plants she obtained in Glenwood Park (which surrounds the Garden), and thus, it is indigenous to the Garden area. This plant was listed on Martha Crone's 1951 inventory of plants in the Garden at that time. The plant is native to Minnesota and well distributed except for a few scattered counties. The plants in the Garden appear to be the subspecies A. ludoviciana Nutt. ssp. ludoviciana which is the subspecies native to Minnesota.

Subspecies of A. ludoviciana: Artemisia is large genus with five subgenera. One of those five is Artemisia subg. Artemisia within which there are 28 species in North America, one of which is Artemisia ludoviciana and in that species there are 6 subspecies allowing for widespread distribution. Ssp. ludoviciana is widespread, absent only in the far north of the continent, the Canadian east coastal provinces and several of the U.S. states in the SE. It is differentiated from the other five subspecies by not having deeply lobed leaves, which eliminates subsp. candicans and subsp. incompta. The other four have entire or shallowly lobed leaves with flower heads in either a panicle or raceme type array. If the array is 8 cm or larger in diameter, and leaves under 2 cm, we eliminate subsp. albula. If the leaf margins are plane and not revolute (the edges turned back), we have our subspecies here. The other two subspecies have revolute leaves - subsp. redolens and subsp. mexicana.

There are nine species of Artemisia known in Minnesota (3 more are obscure). On the nine, four are introduced and five are native. The four introductions, A. aboratanum, A. absinthium, A. biennis and A. vulgaris, were originally brought from Europe for seasoning and medicinal uses and are referred to as 'Wormwoods'. Of the native varieties there is extensive literature on use by native peoples. Two of the nine are in subgenera Absinthium (A. absinthium and A. frigida); two are in subgenera Drancunculus (A. campestris and A. drancunculus) and the remainder are in subgenera Artemisia (A. aboratanum, A. bernnis, A. ludoviciana, A. vulgaris and A. serrrata.)

References and site links

References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.

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