''Hypericum aegypticum'' is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
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 ...
of the St. John's wort
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
(
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. '' ...
) which is native to the
Eastern Mediterranean
Eastern Mediterranean is a loose definition of the eastern approximate half, or third, of the Mediterranean Sea, often defined as the countries around the Levantine Sea.
It typically embraces all of that sea's coastal zones, referring to communi ...
. It was described by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in the second volume of his ''
Species Plantarum
' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...
'' in 1753, who named it after Egypt despite it not being distributed there. The plant is commonly known as shrubby St. John's wort or Egyptian St. John's wort in English. Like other members of section ''
Adenotrias'', it is found among
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
rocks in coastal areas. While it has been evaluated as
threatened
Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of ''critical depensa ...
on the island of
Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
, the species has no legal protections.
The species is a
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 ...
or shrublet that grows up to 2 meters (6.5 feet) tall with many branches, each having a single small flower with five yellow petals and many
stamens
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 ...
. Its leaves
lack hairs, and have densely patterned glands and large
primary veins. The species is notable for its
heterostyly
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, termed "morphs", exist in the population. On each individual plant, all flowers share the same morph ...
, a trait which within the ''Hypericum'' genus is unique to
section ''Adenotrias'', and exhibits one of two heterostylous flower types called "pins" and "thrums". It has three subspecies, which vary in their distribution and
phytochemical
Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as poisons ...
makeup.
Description
![Hypericum aegypticum (Overhead, in rocks)](https://upload.wikimedia.org/wikipedia/commons/3/38/Hypericum_aegypticum_%28Overhead%2C_in_rocks%29.jpg)
''Hypericum aegypticum'' is a
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 ...
or shrublet that varies in height from 0.05 to 2 meters (0.16 to 6.5 feet) tall. It grows in a crowded, spreading pattern, with its stems stretching out from the center of the plant. The branches grow roughly perpendicular from these stems, but can also spread out in different directions. It has a
chromosome number
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectivel ...
of 2n=20.
Stems
The
stems of ''Hypericum aegypticum'' usually have two visible lines running along their length, but can sometimes have four. When the plant is young, the stems are a flatter shape with two edges (
ancipitous), but quickly become more cylindrical as the plant matures. In a cross-section, the profile of the stems is circular and lacks
wing-like extensions. They have a
vessel density of roughly two vessels per square millimeter of stem, with each of these vessels measuring 15 micrometers in diameter. In between the nodes where the leaves branch from (in the
internodes
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrien ...
), there are small leaf-like structures which are shorter than the true leaves.
The
xylem
Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
in the stems, a type of transport tissue, differs from other similar species of ''Hypericum.'' The xylem of ''H. aegypticum'' is diffuse; it is spread evenly throughout the stem. In other similar species, the xylem is ring-porous and more dense in a series of concentric rings. There are two secretory structures in the stems: small secretory canals in the
phloem
Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...
and many large secretory canals in the
cortex
Cortex or cortical may refer to:
Biology
* Cortex (anatomy), the outermost layer of an organ
** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain''
*** Motor cortex, the regions of the cerebral cortex i ...
.
Leaves
The leaves of ''Hypericum aegypticum'' are free and range from
sessile
Sessility, or sessile, may refer to:
* Sessility (motility), organisms which are not able to move about
* Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant
* Sessility (medicine), tumors and polyps that ...
to shortly
petiolate. They persist for around two seasons. The blades are long and wide. Their shape is elliptic or narrowly oblong. The leaves are the same color as the rest of the plant and have a texture similar to that of leather. The shape of their tip can range from acute to obtuse and the base of the leaf is wedge-shaped. The leaves lack hairs (
trichome
Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a pla ...
s) on both the top and bottom.
They have one pair of lateral
veins
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated b ...
, with the
midrib
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary o ...
sometimes branched and visible beneath them. Their primary veins are very large and straight and are highly rigid. The secondary veins branch off at acute angles of wide divergence, and some tertiary veins with a branched pattern are also present.
The laminar and marginal glands are dense. Unlike some species of ''Hypericum'', such as ''
H. perforatum'', ''H. aegypticum'' lacks black nodules on its leaves. Instead, it has small translucent glands which measure 54 by 45 micrometers and are found in the
mesophyll
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
.
The upper sides of the leaves have an outer layer (
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water rele ...
) made of cells with linear walls and rounded corners. This upper side also has
stoma
In botany, a stoma (from Greek ''στόμα'', "mouth", plural "stomata"), also called a stomate (plural "stomates"), is a pore found in the epidermis of leaves, stems, and other organs, that controls the rate of gas exchange. The pore is bor ...
ta that are surrounded by smaller cells. The lower side of the leaves have a similar composition to the upper side, but with a higher density of stomata. On both sides, there is a
cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
that extends over the entire surface, even over the
guard cell
Guard cells are specialized plant cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore. The stomatal pores are largest when ...
s, which makes them very hard to distinguish. This thick cuticle leads to increased impermeability in areas where there are encrusted deposits.
Inflorescence
''Hypericum aegypticum'' is one-flowered, and its
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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
is
terminal
Terminal may refer to:
Computing Hardware
* Terminal (electronics), a device for joining electrical circuits together
* Terminal (telecommunication), a device communicating over a line
* Computer terminal, a set of primary input and output dev ...
and grows from around four
axils
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
below. It has short flowering branches past a "sterile" region which lacks them. These branches grow from around eleven different nodes. However, some plants lack the sterile region and can have flowers or flowering branches from up to twenty-two nodes. The inflorescence is similar in appearance to a
spike
Spike, spikes, or spiking may refer to:
Arts, entertainment, and media
Books
* ''The Spike'' (novel), a novel by Arnaud de Borchgrave
* ''The Spike'' (book), a nonfiction book by Damien Broderick
* ''The Spike'', a starship in Peter F. Hamilto ...
, with longer branches below the flowering region. The
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 usually different from foliage leaves. They may be smaller, larger, or of ...
s are often absent, but when they are present they are leaf-like in appearance, with a clasping
calyx and several types of glands. The
pedicels
In botany, a pedicel is a stem that attaches a single flower to the inflorescence. Such inflorescences are described as ''pedicellate''.
Description
Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...
are very short or absent altogether.
![Hypericum aegypticum Malta 02](https://upload.wikimedia.org/wikipedia/commons/7/78/Hypericum_aegypticum_Malta_02.jpg)
The flowers of ''H. aegypticum'' range from in diameter. The shape of the
buds
In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of a stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specia ...
is a narrow form between an oval and an ellipse which tapers to a rounded point. 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 ...
s are green and are by in size. They overlap one another and are not quite the same size. Their shape ranges from oblong to elliptic, but they can also be
lance-like in form. Their ends can be rounded, pointed, or obtuse. The sepals are hood-like and stand stiffly erect, and have roughly nine unbranched veins with prominent
midribs and linear laminar glands. The
petal
Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...
s of the flower range from bright yellow to a rather pale shade of yellow. They are by in size. They are persistent in fruit and there are roughly twice as many of them as there are sepals.
There are 18–48
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 per inflorescence, with single
fascicles containing 5–10 stamens and double fascicles containing 5–29 stamens. There are united
filaments in each fascicle, the longest of which are in long-styled individuals and in short-styled individuals. Some stamen fascicles are sterile and are long and flat-topped. The
ovaries
The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...
are by in size and are narrow or very narrow and acute to truncate.
The
seed capsule
In botany a capsule is a type of simple, dry, though rarely fleshy dehiscent fruit produced by many species of angiosperms (flowering plants).
Origins and structure
The capsule (Latin: ''capsula'', small box) is derived from a compound (multica ...
is by in size. Its shape is that of a cylindric ellipsoid to a rather broad ellipsoid. It is longer than the sepals, and its valves run longitudinally and have oil tubes. The seeds are dark brown and roughly long and lack a longitudinal ridge. The
testa have small linear pits or wrinkles, and the
elaiosome
Elaiosomes ( grc, ἔλαιον ''élaion'' "oil" + ''sóma'' "body") are fleshy structures that are attached to the seeds of many plant species. The elaiosome is rich in lipids and proteins, and may be variously shaped. Many plants have elaio ...
is often lobed.
Heterostyly
![Hypericum aegypticum GotBot 2015 003](https://upload.wikimedia.org/wikipedia/commons/8/80/Hypericum_aegypticum_GotBot_2015_003.jpg)
Individual plants of ''Hypericum aegypticum'' exhibit one of two different sets of characteristics, called
distyly Distyly is a type of heterostyly in which a plant demonstrates reciprocal herkogamy. This breeding system is characterized by two separate flower morphs, where individual plants produce flowers that either have long styles and short stamens (L-morp ...
. This
polymorphism is characterized by two different types of flowers: one has long
styles and short stamens (such specimens are called "pins"), the other has short styles and long stamens (such specimens are called "thrums"). In this species, pin flowers produce and receive more pollen grains than thrum flowers. This is unusual, as it does not fit with the expected course of natural selection; plants in the species which produce and receive more pollen would be expected to outcompete those that produce and receive less. While pin flowers are more common in the wild with a ratio of approximately 3 pins to 1 thrum, that difference is only because the
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
which codes for the pin is
dominant while the thrum is recessive, and the 3:1 ratio is consistent with traits that have no effect on reproduction.
''Hypericum'' sect. ''Adenotrias'' is the only section in ''Hypericum'' that exhibits heterostyly, and all of its species, including ''Hypericum aegypticum'', are distylous. This trait is thought to have evolved within the genus as opposed to being primitive and is one of the unique characteristics of sect. ''Adenotrias''. In studies of eleven
angiosperm
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 ...
genera which exhibited distyly, all but ''Hypericum'' followed a genetic system called the ''
Primula
''Primula'' () is a genus of herbaceous flowering plants in the family Primulaceae. They include the primrose ('' P. vulgaris''), a familiar wildflower of banks and verges. Other common species are '' P. auricula'' (auricula), '' P. veris'' (cow ...
'' system, in which the "thrum" form was dominant and the "pin" form was recessive. However, for an unknown reason, the opposite appears to be the case for the species of ''Hypericum''.
Phytochemistry
The
phytochemistry of ''Hypericum aegypticum'' varies a great deal depending on which subspecies is analyzed. Subspecies ''aegypticum'', ''maroccanum'', and ''webii'' are all highly different in their major essential oil components, with only three constituents being found in common in all of the subspecies:
spathulenol,
caryophyllene
Caryophyllene (), more formally (−)-β-caryophyllene, (BCP), is a natural bicyclic sesquiterpene that is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of '' Syzygium aromaticum'' (cloves), the ess ...
oxide, and ''E''-caryophellene. The major constituent of subsp. ''aegypticum'' is
ishwarane (a
sesquiterpene
Sesquiterpenes are a class of terpenes that consist of three isoprene units and often have the molecular formula C15H24. Like monoterpenes, sesquiterpenes may be cyclic or contain rings, including many unique combinations. Biochemical modificat ...
) the major constituent of subsp. ''maroccanum'' is
caryophyllene
Caryophyllene (), more formally (−)-β-caryophyllene, (BCP), is a natural bicyclic sesquiterpene that is a constituent of many essential oils, especially clove oil, the oil from the stems and flowers of '' Syzygium aromaticum'' (cloves), the ess ...
, and the major constituent of subsp. ''webii'' is
pinene
Pinene is a collection of unsaturated bicyclic monoterpenes. Two geometric isomers of pinene are found in nature, α-pinene and β-pinene. Both are chiral. As the name suggests, pinenes are found in pines. Specifically, pinene is the major comp ...
. These differences in the compounds detected in the species reveal that
morphologically different populations of ''H. aegypticum'' are also likely to differ phytochemically. ''S''mall amounts of other
metabolites
In biochemistry, a metabolite is an intermediate or end product of metabolism.
The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...
are also present in ''H. aegypticum'', including
flavonoids
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 ...
(3.95 g/kg),
biflavones (1.45 g/kg),
acylphloroglucinols (1.15 g/kg),
cinnamic acids (0.35 g/kg), and
naphtodianthrones (0.05 g/kg).
Essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
extracts from ''Hypericum aegypticum'' subsp. ''webbii'' were shown ''
in vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...
'' to have moderate
antimicrobial
An antimicrobial is an agent that kills microorganisms or stops their growth. Antimicrobial medicines can be grouped according to the microorganisms they act primarily against. For example, antibiotics are used against bacteria, and antifungals ar ...
effects against
Gram-positive bateria such as ''
Bacillus subtilis
''Bacillus subtilis'', known also as the hay bacillus or grass bacillus, is a Gram-positive, catalase-positive bacterium, found in soil and the gastrointestinal tract of ruminants, humans and marine sponges. As a member of the genus ''Bacillu ...
'', ''
Enterococcus faecalis
''Enterococcus faecalis'' – formerly classified as part of the group D ''Streptococcus'' system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans. Like other species in the genus ''Enterococcus'', ''E ...
'', ''
Staphylococcus epidermidis
''Staphylococcus epidermidis'' is a Gram-positive bacterium, and one of over 40 species belonging to the genus '' Staphylococcus''. It is part of the normal human microbiota, typically the skin microbiota, and less commonly the mucosal microbio ...
'', and ''
Micrococcus luteus
''Micrococcus luteus'' is a Gram-positive, to Gram-variable, nonmotile, coccus, tetrad-arranging, pigmented, saprotrophic bacterium that belongs to the family Micrococcaceae. It is urease and catalase positive. An obligate aerobe, ''M. luteus' ...
''.
Distribution and habitat
![Hypericum aegypticum habitat](https://upload.wikimedia.org/wikipedia/commons/c/cb/Hypericum_aegypticum_habitat.jpg)
''Hypericum aegypticum'' can be found frequently in the wild and is
indigenous
Indigenous may refer to:
*Indigenous peoples
*Indigenous (ecology), presence in a region as the result of only natural processes, with no human intervention
*Indigenous (band), an American blues-rock band
*Indigenous (horse), a Hong Kong racehorse ...
to
Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
,
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...
,
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...
,
Algeria
)
, image_map = Algeria (centered orthographic projection).svg
, map_caption =
, image_map2 =
, capital = Algiers
, coordinates =
, largest_city = capital
, relig ...
, and
Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to Egypt–Libya bo ...
.
However, its distribution across these countries is unusual because it is highly fragmented into several different population strands.
The three subspecies are divided among these strands: ''H. aegypticum'' subsp. ''aegypticum'' is native to Libya; subsp. ''maroccanum'' is native to Morocco and Algeria; subsp. ''webbii'' is native to Sardinia, Sicily, Malta, and Greece.
''H. aegypticum'' is found among
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
rocks and
scree
Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically ha ...
in valleys of coastal areas. It is found at elevations from sea level to 1600 meters (5250 feet) above sea level.
In some habitats, particularly more wind-swept or exposed areas, the species has been observed in much denser, carpet-like growth patterns, sometimes growing to only tall. However, the species grows best in open, sunny areas free of other plants which could compete with it.
While ''H. aegypticum'' has been identified by the Maltese
Red Data Book
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biolog ...
as having a threatened status on Malta, no legal action has been taken for the protection of the species as of 2021.
Cultivation
While ''Hypericum aegypticum'' is not widely cultivated, it is present in
botanical gardens
A botanical garden or botanic gardenThe terms ''botanic'' and ''botanical'' and ''garden'' or ''gardens'' are used more-or-less interchangeably, although the word ''botanic'' is generally reserved for the earlier, more traditional gardens, an ...
, including in a greenhouse at the
University of Oxford Botanic Garden
The University of Oxford Botanic Garden is the oldest botanic garden in Great Britain and one of the oldest scientific gardens in the world. The garden was founded in 1621 as a physic garden growing plants for medicinal research. Today it conta ...
.
Taxonomy
![Species plantarum 002](https://upload.wikimedia.org/wikipedia/commons/9/98/Species_plantarum_002.JPG)
''Hypericum aegypticum'' was first described by
Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in his second volume of ''
Species Plantarum
' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...
'' in 1753. He noted the species' Egyptian habitat, its often paired leaves, growing pattern, and the shape of its leaves.
However, even though Linnaeus mentioned "Aegypto" and claimed that his type specimen for the species was from Egypt, ''H. aegypticum'' is not actually native to Egypt, and the specimen Linnaeus used most likely came from one of the
Libyan
Demographics of Libya is the demography of Libya, specifically covering population density, ethnicity, education level, health of the populace, economic status, and religious affiliations, as well as other aspects of the Libyan population. The ...
populations. Today, ''H. aegypticum'' is commonly referred to in English as Shrubby St. John's Wort or Egyptian St. John's Wort, while in
Malta
Malta ( , , ), officially the Republic of Malta ( mt, Repubblika ta' Malta ), is an island country in the Mediterranean Sea. It consists of an archipelago, between Italy and Libya, and is often considered a part of Southern Europe. It lies ...
it is known as Fexfiex tal-irdum.
The species' placement within ''Hypericum'' can be summarized as follows:
''
Hypericum
''Hypericum'' is a genus of flowering plants in the family Hypericaceae (formerly considered a subfamily of Clusiaceae). The genus has a nearly worldwide distribution, missing only from tropical lowlands, deserts and polar regions. Many ''Hype ...
''
:
''Hypericum'' subg. ''Hypericum''
::
''Hypericum'' sect. ''Adenotrias''
::: ''
Hypericum russeggeri''
::: ''
Hypericum aciferum''
::: ''Hypericum aegypticum''
History
After the original description by Linnaeus, various botanists identified the plant under different names which are now considered
invalid synonyms of the species.
Michel Adanson
Michel Adanson (7 April 17273 August 1806) was an 18th-century French botanist and naturalist who traveled to Senegal to study flora and fauna. He proposed a "natural system" of taxonomy distinct from the binomial system forwarded by Linnaeus.
...
, in his 1763 work establishing the genus ''Elodes'', erroneously described the species ''
Hypericum elodes'' by relying upon a supposed description by Linneaus of the species in his 1753 ''Species Plantarum''. However, the name ''H. elodes'' did not appear it was mentioned in the 1762 ''
Flora Anglica'', and the name that Adanson actually referenced was ''Hypericum aegypticum''. Therefore, his description under ''H. elodes'' is considered a synonym of ''H. aegypticum''. Confusion around ''Elodes'' continued, but it was eventually restricted to only the species ''H. elodes'' as defined by Linneaus. In the early 19th century, the species ''Hypericum'' were being divided into numerous smaller, new genera by different authors.
Antoine Laurent de Jussieu
Antoine Laurent de Jussieu (; 12 April 1748 – 17 September 1836) was a French botanist, notable as the first to publish a natural classification of flowering plants; much of his system remains in use today. His classification was based on an e ...
divided it into five genera, confusingly including ''Elodea.''
Édouard Spach
Édouard Spach (23 November 1801 – 18 May 1879) was a French botanist.
The son of a merchant in Strasbourg, in 1824 he went to Paris, where he studied botany with René Desfontaines (1750–1831) and Antoine-Laurent de Jussieu (1748–1836). ...
contributed his own restrictive genera, and placed ''H. aegypticum'' first into ''Triadenia'' and then ''Adenotrias''. Finally,
Robert Keller reduced all of these new genera to sections within ''Hypericum'' in 1925, bringing ''H. aegypticum'' back into ''Hypericum'' in
section ''Adenotrias''.
In 1996, British taxonomist
Norman Robson published the sixth volume of his comprehensive
monograph
A monograph is a specialist work of writing (in contrast to reference works) or exhibition on a single subject or an aspect of a subject, often by a single author or artist, and usually on a scholarly subject.
In library cataloging, ''monograph ...
on the genus ''Hypericum.'' In this volume, Robson recognized Linnaeus' original name as correct and maintained ''H. aegypticum'' in sect. ''Adenotrias'', incorporating it into his new framework of 36 sections. ''Adenotrias'' was established to comprise three species of shrubs found among limestone rocks which vary greatly in appearance. However, the species of the section were united because they shared the trait of heterostyly.
Phylogeny
Molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
has demonstrated that ''Hypericum aegypticum'' is most closely related to ''
H. balfourii'' and ''
H. socotranum'' of
sect. ''Campylosporus''''.'' However, no conclusive evidence was found which would suggest that these similarities would warrant the inclusion of ''H. aegypticum'' in sect. ''Campylosporus.'' Phylogenetic studies have also found that ''
H. heterophyllum'', despite lacking the floral specializations and heterostyly of ''H. aegypticum'', has similar characteristics to the species, especially ''H. aegypticum'' subsp. ''maroccanum''. This suggests that ''H. heterophyllum'' is a derivative of the species which has lost some of the specializations that are unique to ''H. aegypticum'' and sect. ''Adenotrias''.
Subdivision
![Hypericum aegypticum Malta 01](https://upload.wikimedia.org/wikipedia/commons/1/18/Hypericum_aegypticum_Malta_01.jpg)
The following subspecies are accepted by
Plants of the World Online
Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...
:
* ''Hypericum aegypticum'' subsp. ''aegypticum''
* ''Hypericum aegypticum'' subsp.'' maroccanum''
(Pau) N. Robson
* ''Hypericum aegypticum'' subsp.'' webbii''
(Spach) N. Robson
Beyond their separate distributions, the subspecies also vary slightly in appearance. Subsp. ''maroccanum'' grows more upright than its counterparts, subsp. ''webbii'' is typically taller and larger, and subsp. ''aegypticum'' has petals that are somewhat shorter. Additionally, the branches of ''maroccanum'' tend to reach upwards, while ''aegypticum'' usually forms a lower bush. Lastly, the leaves of ''maroccanum'' are markedly larger than ''aegypticum'' or ''webbii''.
Subspecies ''maroccanum'' was originally described as a
variety
Variety may refer to:
Arts and entertainment Entertainment formats
* Variety (radio)
* Variety show, in theater and television
Films
* ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont
* ''Variety'' (1935 film), ...
of ''H. aegypticum'' by
Carlos Pau
Carlos may refer to:
Places
;Canada
* Carlos, Alberta, a locality
;United States
* Carlos, Indiana, an unincorporated community
* Carlos, Maryland, a place in Allegany County
* Carlos, Minnesota, a small city
* Carlos, West Virginia
;Elsewhere ...
in 1932, while subsp. ''webbii'' was originally considered to be its own species under the name ''Triadenia webbii'' by Édouard Spach in 1836. Norman Robson reclassified both as subspecies of ''H. aegypticum'' in 1993, and established subsp. ''aegypticum'' to denote those specimens which were separate from both ''maroccanum'' and ''webbii''.
References
{{Taxonbar, from=Q16653686
aegypticum
Flora of Malta
Flora of Libya
Flora of Greece
Flora of Morocco
Flora of Algeria
Taxa named by Carl Linnaeus
Plants described in 1753