''Hypericum calycinum'' is a species of prostrate or low-growing

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

in the

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

family

Hypericaceae Hypericaceae is a plant family in the order Malpighiales, comprising six to nine genera and up to 700 species, and commonly known as the St. John's wort family. Members are found throughout the world apart from extremely cold or dry habitats. '' ...

. Widely cultivated for its large yellow flowers, its names as a

garden plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

include Rose-of-Sharon in

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

and

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

, and Aaron's beard, great St-John's wort, creeping St. John's wortHypericum calycinum. (n.d.). Retrieved April 9, 2018, from
/ref> and Jerusalem star. Grown in Mediterranean climates, widely spread in the Strandja Mountains along the Bulgarian and Turkish Black Sea coast.

Description

''Hypericum calycinum'' is a low, creeping,

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

woody shrub (classified as a subshrub or shrublet) to about 1 m tall and 1–2 m wide but often smaller. The green, ovate leaves grow in opposite pairs. Usually 4 inches long, the undersides of the leaves are net-veined. In the sun, the leaves are a vibrant green color, and in shade, the leaves are a lighter yellow-green. The underside of the leaves is a blue-green color and in the fall, the leaves take on a purple color.Hypericum calycinum. (n.d.). Retrieved April 9, 2018, from
/ref> The flowers are 3–5 cm in diameter, a rich yellow, with five petals and numerous yellow

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s. Its flowers can be described as “rose-like” and tend to be single or in units of two or three, flowering in June to September. ''Hypericum calycinum'' is indigenous to southeast

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

and southwest

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

. It is a popular, semi-

garden shrub with many named

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

s and

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

s derived from it. Although the genus is generally not affected by

rust fungi Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales (previously known as Uredinales). An estimated 168 rust genera and approximately 7,000 species, more than half of which belong to the genus ''Puccinia'', are currently a ...

, it can appear on ''H. calycinum'' (and another cultivated plant, ''Hypericum'' × ''inodorum'' 'Elstead').

Usage

Various species of the genus ''Hypericum'' have been used since ancient times as

herbal remedies Herbal medicine (also herbalism) is the study of pharmacognosy and the use of medicinal plants, which are a basis of traditional medicine. With worldwide research into pharmacology, some herbal medicines have been translated into modern remedie ...

.Öztürk, Y., Aydin, S., Beis, R., Başer, K. H. C., & Berberoĝlu, H. (1996). Effects of Hypericum perforatum L. and Hypericum calycinum L. extracts on the central nervous system in mice. ''Phytomedicine'', ''3''(2), 139–146. This species has been used traditionally to reduce

muscle spasms A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a muscle c ...

and for the treatment of

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

.Mat, A. (2013). An overview on Hypericum species of Turkey. ''Journal of Pharmacognosy and Phytotherapy'', ''5''(3), 38–46. ''Hypericum calycinum'' is an economically valuable plant in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

, commonly used for ornamental reasons and

landscaping Landscaping refers to any activity that modifies the visible features of an area of land, including the following: # Living elements, such as flora or fauna; or what is commonly called gardening, the art and craft of growing plants with a goal o ...

. Under ideal growing conditions, from full sun to partial shade and well-drained

acidic soil Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the neg ...

, this species can grow rapidly. Although resilient in many soil types, this species grows best in sandy or

loam Loam (in geology and soil science) is soil composed mostly of sand (particle size > ), silt (particle size > ), and a smaller amount of clay (particle size < ). By weight, its mineral composition is about 40–40–20% concentration of sand–sil ...

y soils. This shrub grows through

underground stem Underground stems are modified plant parts that derive from stem tissue but exist under the soil surface. They function as storage tissues for food and nutrients, in propagation of new clones, and in perennation (survival from one growing season to ...

s and is typically grown as

ground cover Groundcover or ground cover is any plant that grows over an area of ground. Groundcover provides protection of the topsoil from erosion and drought. In an ecosystem, the ground cover forms the layer of vegetation below the shrub layer known as t ...

or to stabilize soil on hills and requires low maintenance. It does have the potential to become invasive, as reported in some areas of

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, due to its ability to grow rapidly by

stolon In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external s ...

s. While generally easy to take care of, this species is suggested to be cut down each spring. According to the

USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

, this species is used as nursery stock product.Conservation Plant Characteristics for Hypericum calycinum. (n.d.). Retrieved April 11, 2018, from https://plants.usda.gov/java/charProfile?symbol=HYCA10

Etymology

In North America the name Rose of Sharon is applied to a species in a different order, ''

Hibiscus syriacus ''Hibiscus syriacus'' is a species of flowering plant in the mallow family, Malvaceae. It is native to Korea, and south-central and southeast China, but widely introduced elsewhere, including much of Asia. It was given the epithet ''syriacus'' b ...

.'' The common name of St. John's wort, which is used to describe plants of the entire genus, arose from the old tradition of ''Hypericum'' plants being burned on the eve of St. John's Day, to stave off evil spirits. The species name, ''calycinum'', comes from the flower's prominent calyx, the

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

of the

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

Research

This species is capable of producing the same medicinally active components as ''H. perforatum'' (

hyperforin Hyperforin is a phytochemical produced by some of the members of the plant genus ''Hypericum'', notably ''Hypericum perforatum'' (St John's wort). Hyperforin may be involved in the pharmacological effects of St. John's wort, specifically in its a ...

etc.), though in different ratios, with

adhyperforin Adhyperforin is a phytochemical found in the members of the plant genus ''Hypericum'' including St. John's Wort. It has a very similar pharmacological profile to hyperforin and acts as a TRPC6 ion channel activator, thereby inhibiting the reuptak ...

predominating, and a low level of hyperforin present. Research has shown that the UV pigments of the ''Hypericum calycinum'' flower stave off predators such as

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

s and

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

s. One type of DIP (dearomatized isoprenylated phloroglucinols), a category of pigments alongside

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s, was found to be toxic to a caterpillar as well. A large quantity of DIPs were found in the male and female reproductive organs, which furthers emphasizes the use of DIPs as a defense mechanism. These pigments also serve a dual function to attract pollinators, as they are visible to insects and not humans.Gronquist, M., Bezzerides, A., Attygalle, A., Meinwald, J., Eisner, M., & Eisner, T. (2001). Attractive and defensive functions of the ultraviolet pigments of a flower (Hypericum calycinum). ''Proceedings of the National Academy of Sciences'', ''98''(24), 13745-13750. Recent research on mice has shown that the alcoholic extracts from ''Hypericum calycinum'' have antidepressant effects and are comparably as effective as antidepressant drugs, such as

desipramine Desipramine, sold under the brand name Norpramin among others, is a tricyclic antidepressant (TCA) used in the treatment of depression. It acts as a relatively selective norepinephrine reuptake inhibitor, though it does also have other activiti ...

and

trimipramine Trimipramine, sold under the brand name Surmontil among others, is a tricyclic antidepressant (TCA) which is used to treat depression. It has also been used for its sedative, anxiolytic, and weak antipsychotic effects in the treatment of insomn ...

. Unlike the rest of the genus, ''H. calycinum'' does not have

hypericin Hypericin is a naphthodianthrone, an anthraquinone derivative which, together with hyperforin, is one of the principal active constituents of ''Hypericum'' (Saint John's wort). Hypericin is believed to act as an antibiotic, antiviral and non-speci ...

, which causes

photosensitization Photosensitizers produce a physicochemical change in a neighboring molecule by either donating an electron to the substrate or by abstracting a hydrogen atom from the substrate. At the end of this process, the photosensitizer eventually returns to ...

, which causes the side effects of flush, fatigue, and

pruritus Itch (also known as pruritus) is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to be classified as any one type of sensory experience. Itch has many similarities to pain, and while both are unpleasant ...

when used in drugs. These extracts have the potential to be a remedy for depression without these side effects common in current antidepressants. However, more research is required.

References

{{Taxonbar, from=Q159330 calycinum Groundcovers Flora of Europe Flora of Asia