Salvia yangii

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Salvia yangii, previously known as Perovskia atriplicifolia (Template:IPAc-en), and commonly called Russian sage,<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> is a flowering herbaceous perennial plant and subshrub. Although not previously a member of Salvia, the genus widely known as sage, since 2017 it has been included within them.<ref name="B.T.Drew_et_al.">Template:Cite journal</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> It has an upright habit, typically reaching Template:Convert tall, with square stems and gray-green leaves that yield a distinctive odor when crushed. It is best known for its flowers. Its flowering season extends from mid-summer to late October, with blue to violet blossoms arranged into showy, branched panicles.

It is native to the steppes and hills of southwestern and central Asia. Successful over a wide range of climate and soil conditions, it has since become popular and widely planted. Several cultivars have been developed, differing primarily in leaf shape and overall height; 'Blue Spire' is the most common. This variation has been widely used in gardens and landscaping. S. yangii was the Perennial Plant Association's 1995 Plant of the Year, and the 'Blue Spire' cultivar received the Award of Garden Merit from the Royal Horticultural Society.

The species has a long history of use in traditional medicine in its native range, where it is employed as a treatment for a variety of ailments. This has led to the investigation of its phytochemistry. Its flowers can be eaten in salads or crushed for dyemaking, and the plant has been considered for potential use in the phytoremediation of contaminated soil.

DescriptionEdit

File:Perovskia atriplicifolia 3.jpg

Flowers, showing the hair-covered calyx, tube-shaped corolla, and exserted style

Salvia yangii is a deciduous perennial subshrub with an erect to spreading habit.Template:Sfn Template:Sfn Superficially, it resembles a much larger version of lavender.Template:Sfn Multiple branches arise from a shared rootstalk,Template:Sfn growing to a height of Template:Convert,Template:Sfn Template:Sfn with occasional specimens reaching Template:Convert.Template:Sfn The mature plant may be Template:Convert across.Template:Sfn The rigid stems are square in cross-section,Template:Sfn and are covered by an indumentum formed by stellate, or star-shaped, trichomes and oil droplets.Template:Sfn Especially during autumn, these hairs give the stems a silvery appearance.Template:Sfn

The grayish-green leaves are arranged in opposite pairs,Template:Sfn Template:Sfn and attached to the stems by a short petiole.Template:Sfn They are generally Template:Convert long and Template:Convert wide,Template:Sfn although narrower in some populations.Template:Sfn The overall leaf shape is oblate, a rounded shape longer than it is wide, to lanceolate, shaped like the head of a lance.Template:Sfn They are pinnatipartite,Template:Sfn with a deeply incised leaf margin that may be either wavy or sharp-toothed; even within a single community of S. yangii, there can be considerable variation in the details of leaf shape.Template:Sfn Leaves near the top of branches may merge into bracts.Template:Sfn The foliage is aromatic, especially when crushed,Template:Sfn with a fragrance described as sage-like,Template:Sfn a blend of sage and lavender,Template:Sfn or like turpentine.Template:Sfn

The flowering season of S. yangii can be as long as June through October,Template:Sfn although populations in some parts of its range, such as China, may bloom in a much more restricted period.Template:Sfn The inflorescence is a showy panicle, Template:Convert,Template:Sfn with many branches.Template:Sfn Each of these branches is a raceme, with the individual flowers arranged in pairs called verticillasters.Template:Sfn Each flower's calyx is purple, densely covered in white or purple hairs, and about Template:Convert long. The corolla is tube-shaped, formed from a four-lobed upper lip and a slightly shorter lower lip; the blue or violet blue petals are about 1 cm long.Template:Sfn Template:Sfn The style has been reported in both an exserted—extending beyond the flower's tube—form and one contained within the flower;Template:Sfn all known examples of S. yangii in cultivation have exserted styles.Template:Sfn Gardening author Neil Soderstrom describes the appearance of the flowers from a distance as "like a fine haze or fog".Template:Sfn

The fruits develop about a month after flowering,Template:Sfn and consist of dark brown oval nutlets, about Template:Convert.Template:Sfn

PhytochemistryEdit

The phytochemistry of Russian sage is under basic research. Analysis of its essential oil has identified over two dozen compounds,Template:Sfn although the compounds detected and their relative prevalence have not been consistent. Most analyses have identified various monoterpenes and monoterpenoids as the dominant components, such as carene, eucalyptol, limonene, γ-terpinene, and (+)-β-thujone,Template:Sfn Template:Sfn although the essential oil of a sample from the Orto Botanico dell'Università di Torino had camphor as its most prevalent component.Template:Sfn Other monoterpenes, camphene, α-pinene,Template:Sfn and β-pinene are also present,Template:Sfn as are sesquiterpenes such as γ-cadinene,Template:Sfn δ-cadinene, trans-caryophyllene, and α-humulene.Template:Sfn Several terpenoid alcohols—borneol, cedrol, and menthol Template:Sfn—have been extracted, as have caffeic acid and ferulic acid.Template:Sfn More complex compounds have been isolated, some of which were first identified in this manner, including perovskatone;Template:Sfn the glycosides atriplisides A and B;Template:Sfn and atricins A and B, a pair of triterpenes that are similar to oleanane.Template:Sfn Four diterpene glucosides have been isolated by extraction.<ref name="Gao">Template:Cite journal</ref>

Similar speciesEdit

Nine species are recognised within Salvia subg. Perovskia.Template:Sfn S. abrotanoides shares much of the range of S. yangii, but is distinguished by its bipinnate leaves.Template:Sfn Template:Sfn Hybrids between these two species may occur naturally.Template:Sfn Restricted to Turkestan in its native range, P. scrophularifolia is less upright; some forms have white flowers.Template:Sfn The flowers of P. scabiosifolia are yellow.Template:Sfn

TaxonomyEdit

Salvia yangii was described, under the name Perovskia atriplicifolia, by George Bentham in 1848, based on a specimen collected by William Griffith in Afghanistan,Template:Sfn now preserved at the Kew Gardens herbarium as the species's holotype.Template:Sfn The specific epithet atriplicifolia means "with leaves like Atriplex",Template:Sfn referring to its similarity to saltbush.Template:Sfn While commonly known as Russian sage, S. yangii is not native to Russia.Template:Sfn

A population collected in Taxkorgan Tajik Autonomous County, Kashgar Prefecture, Xinjiang, China was described as a separate species in 1987 and given the name Perovskia pamirica,Template:Sfn but was later considered synonymous with P. atriplicifolia.Template:Sfn

In 2017, P. atriplicifolia was transferred to the genus Salvia.<ref name="B.T.Drew_et_al." /> The combinations Salvia atriplicifolia and Salvia pamirica, however, have already been preoccupied by distinct taxa, thus new specific epithet yangii, honouring Yang Changyou, one of the authors of P. pamirica, was given to the species.<ref name="B.T.Drew_et_al." />

PhylogeneticsEdit

Template:Cladogram Within the family Lamiaceae, the large genus Salvia had long been believed monophyletic, based on the structure of its stamens. Several smaller genera, including Dorystaechas, Perovskia, and Meriandra were also included in tribe Mentheae, but were thought to be more distantly related. In 2004, a molecular phylogenetics study based on two cpDNA genes (rbcL and trnL-F) demonstrated that Salvia is not monophyletic, but comprises three identifiable clades. Clade I is more closely related to Perovskia than to other members of Salvia.Template:Sfn

S. yangii has been the subject of subsequent studies seeking to clarify the relationships within Mentheae. Further research combined palynological analysis of pollen grains with rbcL sequencing to provide additional support for the relationship between Perovskia and Salvia clade I. It also distinguished between S. yangii and S. abrotanoides, while confirming their close relationship.Template:Sfn A subsequent multigene study (four cpDNA markers and two nrDNA markers) redrew parts of the Mentheae cladogram, making Rosmarinus a sister group to Perovskia.Template:Sfn

CultivarsEdit

File:Perovskia atriplicifolia E.jpg

The 'Blue Spire' cultivar

Several cultivars of S. yangii have been developed. They are primarily distinguished by the height of mature plants and the depth of the leaf-margin incisions.Template:Sfn Many of these cultivars, especially those with deeply incised leaves, may actually be hybrids of S. yangii and S. abrotanoides.Template:Sfn Template:Sfn In that context, some may be referred to by the hybrid name Perovskia ×hybrida.Template:Sfn Template:Sfn

The most common cultivar,Template:Sfn 'Blue Spire', is among those suspected of being a hybrid.Template:Sfn Template:Sfn It was selected from German plantings by the British Notcutts Nurseries, and first exhibited in 1961.Template:Sfn Template:Sfn 'Blue Spire' grows to approximately Template:Convert, and has large, darker blue flowers.Template:Sfn Template:Sfn In 1993, it received the Royal Horticultural Society's Award of Garden Merit.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

'Filigran' reaches a height of Template:Convert; this tall, sturdy cultivar's name is German for filigree, in reference to its lacy, fern-like foliage.Template:Sfn Template:Sfn 'Little Spire' is shorter, with a mature height of only Template:Convert.Template:Sfn Template:Sfn 'Longin' is similar in height to 'Blue Spire' but more upright.Template:Sfn Allan Armitage established the late-flowering cultivar 'Mystery of Knightshayes' from a plant at Knightshayes Court.Template:Sfn Other cultivars include 'Blue Haze', 'Blue Mist', 'Hybrida' (also called 'Superba'), 'Lace', 'Lisslit', 'Rocketman', and 'WALPPB'.Template:Sfn Template:Sfn Template:Sfn Template:Sfn

Distribution and habitatEdit

Widely distributed across Asia in its native range, S. yangii grows in western China,Template:Sfn northwestern India, Pakistan, Afghanistan, Iran,Template:Sfn Turkey, and parts of eastern Europe.Template:Sfn It is found in steppes and on hillsides,Template:Sfn and grows at higher elevations in mountainous regions, including the Himalayas.Template:Sfn It has been recorded at Template:Convert of altitude in the Karakoram.Template:Sfn In Pakistan's Quetta district, it is often found in association with the grass Chrysopogon aucheri,Template:Sfn and may serve as an indicator species for soils with low calcium carbonate and chloride availability.Template:Sfn The harsh habitats preferred by S. yangii are comparable to the sagebrush steppe of North America.Template:Sfn

EcologyEdit

In parts of its range, such as the Harboi, these steppe ecosystems are employed as rangeland for grazing animals such as sheep and goats, although this forage is generally of poor nutritional quality. S. yangii can serve as an important source of phosphorus and zinc,Template:Sfn despite being high in poorly-digested material such as neutral detergent fiber and lignin.Template:Sfn

CultivationEdit

File:Perovskia atriplicifolia 138-8441.jpg

Illustration from Curtis's Botanical Magazine in 1912

Following its introduction to the United Kingdom in 1904, the Irish gardener and author William Robinson was immediately taken with the plant, which he described as being "worth a place in the choicest garden for its graceful habit and long season of beauty."Template:Sfn The Royal Horticultural Society records the establishment of cultivars beginning with P. 'Hybrida', selected at a Hampshire nursery in the 1930s.Template:Sfn By the late 1980s and early 1990s, S. yangii had gained widespread popularity,Template:Sfn and in 1995, it was selected as the Perennial Plant Association's Plant of the Year.Template:Sfn

The cultivar 'Blue Spire ' has gained the Royal Horticultural Society's Award of Garden Merit.<ref name="RHSPF">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Planting and careEdit

Russian sage is a perennial plant suitable for a wide range of conditions, at least where its tendency to spread will not be a problem. The species prefers full sun.Template:Sfn Specimens planted in partially shaded locations tend to spread or flop,Template:Sfn although this behavior can be controlled somewhat by pinching young shoots or by providing a strong-standing accompaniment that the plant can drape itself around for support.Template:Sfn Template:Sfn Flowers bloom only on new growth.Template:Sfn Plants trimmed to Template:Convert in early spring provide the best subsequent growth and flowering.Template:Sfn Template:Sfn

Tolerant of both heat and cold, it is grown in North America in United States Department of Agriculture hardiness zones three through nine,Template:Sfn Template:Sfn although some cultivars may be better suited than others to extremes of temperature.Template:Sfn Template:Sfn It is successfully grown from the southwestern United States, north and east across much of the country,Template:Sfn and across the Canada–US border into Ontario and Quebec.Template:Sfn Template:Sfn In the coldest of these areas, it may require considerable protection to survive the winter.Template:Sfn In the United Kingdom, the Royal Horticultural Society has assigned it hardiness rating H4,Template:Sfn indicating that it tolerates temperatures as low as Template:Convert, hardy in most of the country through typical winters.Template:Sfn

It also tolerates a variety of soil conditions. Although young specimens perform best when planted in a mixture of peat and either sand or perlite,Template:Sfn Template:Sfn S. yangii can thrive in sandy, chalky, or loamy soil,Template:Sfn or heavy clay soil with sufficient drainage.Template:Sfn It can endure a wide range of soil pH,Template:Sfn as well as exposure to salty conditions near oceans.Template:Sfn Its deep-feeding taproot makes it especially drought tolerant;Template:Sfn for this reason it has seen wide use for xeriscaping in the Intermountain West.Template:Sfn Overwatering and over-fertilization can damage its roots and lead to a rapid decline in health.Template:Sfn Template:Sfn S. yangii is otherwise generally free from plant pathogens.Template:Sfn In cultivation, it is also rarely selected as forage by grazing animals, and so is considered both a deer-resistant and rabbit-resistant plant.Template:Sfn Template:Sfn

LandscapingEdit

File:Purple sagebrush, Raton, NM IMG 4991.JPG

In Raton, New Mexico, showing the airy appearance of the plant

Russian sage has been praised for its usefulness in gardens and landscaping features.Template:Sfn It is most commonly planted as an accent feature,Template:Sfn such as an "island" in an expanse of lawn,Template:Sfn but it can also be used as filler within a larger landscaping feature,Template:Sfn or to enhance areas where the existing natural appearance is retained.Template:Sfn Gardening author Troy Marden describes S. yangii as having a "see-through" quality that is ideal for borders.Template:Sfn Some experts suggest groups of three plants provide the best landscape appearance.Template:Sfn It is also suitable for container gardening.Template:Sfn It does have an undesirable tendency to spread via rhizomes beyond it original planting.

It attracts bees,Template:Sfn hummingbirds,Template:Sfn and butterflies,Template:Sfn and contributes color to gardens—both the blue of its late-season flowers,Template:Sfn and the silvery colors of its winter stalks.Template:Sfn

PropagationEdit

Russian sage is frequently propagated by cuttings. Because its woody crown is resistant to division, softwood cuttings are taken from shoots near the base, generally in late spring.Template:Sfn Template:Sfn Hardwood cuttings selected in mid-to-late summer also provide a viable propagation technique.Template:Sfn Template:Sfn The plant is also grown from seed in cultivation. Such seeds require exposure to cold for 30–160 days to germinate,Template:Sfn Template:Sfn and seed-raised specimens may not preserve the characteristics of named cultivars.Template:Sfn In the commercial greenhouse or nursery setting, its relatively large size and rapid growth can adversely affect quality or make plants more difficult and expensive to transport; the use of plant growth regulators such as chlormequat chloride and daminozide may be more cost-effective than large-scale pruning.Template:Sfn

Some members of the Lamiaceae can spread unchecked and become invasive plants.Template:Sfn Planting of Russian sage near wild lands has been discouraged by some gardening guides out of concern for its potential to spread,Template:Sfn Template:Sfn but it is not yet considered invasive,Template:Sfn and has been suggested as a substitute for purple loosestrife for this reason.Template:Sfn

UsesEdit

File:2008 07 Botanical Garden Meran 71660R0414.jpg

Used as a border in the Trauttmansdorff Castle Gardens, Italy

Russian sage has a long history of use in traditional medicine,Template:Sfn Template:Sfn Template:Sfn and is smoked as a euphoriant.Template:Sfn

In addition to its use in folk medicine, it is sometimes used in Russia to flavor a vodka-based cocktail.Template:Sfn Its flowers are eaten in parts of Afghanistan and Pakistan, including Kashmir,Template:Sfn adding a sweet flavor to salads.

Template:Sfn This species is considered a candidate for use in phytoremediation because of its rapid growth, tolerance for harsh conditions, and ability to accumulate toxic heavy metals from polluted soil.Template:Sfn

The essential oil can function as a biopesticide, especially regarding Tropidion castaneum beetles and Camponotus maculatus carpenter ants.Template:Sfn

ReferencesEdit

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BibliographyEdit

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External linksEdit

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