A false awakening is a vivid scenario in which a person dreams that they have woken up, while still actually asleep.
After a false awakening, subjects often dream they are performing their
daily morning routine such as showering or eating breakfast. False
awakenings, particularly those in which individuals dream they have
awakened from a sleep that involved dreaming, take on aspects of a double dream or a dream within a dream. A classic example in fiction is the double false awakening of the protagonist in Gogol's Portrait (1835).
Some studies have shown that false awakenings are frequently related to lucid dreaming,
often transitioning into one another. The key distinction is that
during a lucid dream, the dreamer recognizes they are dreaming, while in
a false awakening, this awareness is absent.
Related concepts
Lucidity
A false awakening may occur following a dream or following a lucid dream
(one in which the dreamer has been aware of dreaming). Particularly, if
the false awakening follows a lucid dream, the false awakening may turn
into a "pre-lucid dream", that is, one in which the dreamer may start to wonder if they are
really awake and may or may not come to the correct conclusion. In a
study by HarvardpsychologistDeirdre Barrett,
2,000 dreams from 200 subjects were examined and it was found that
false awakenings and lucidity were significantly more likely to occur
within the same dream or within different dreams of the same night.
False awakenings often preceded lucidity as a cue, but they could also
follow the realization of lucidity, often losing it in the process.
False awakenings loops
Because the mind still dreams after a false awakening, there may be
more than one false awakening in a single dream. Subjects may dream they
wake up, eat breakfast, brush their teeth, and so on; suddenly awake
again in bed (still in a dream), begin morning rituals again, awaken
again, and so forth.
The philosopher Bertrand Russell claimed to have experienced "about a hundred" false awakenings in succession while coming around from a general anesthetic.
Protoconscious world
Giorgio Buzzi
suggests that false awakenings may indicate the occasional re-appearing
of a vestigial (or anyway anomalous) REM sleep in the context of
disturbed or hyperaroused sleep (lucid dreaming, sleep paralysis,
or situations of high anticipation). This peculiar form of REM sleep
permits the replay of unaltered experiential memories, thus providing a
unique opportunity to study how waking experiences interact with the
hypothesized predictive model of the world. In particular, it could
permit to catch a glimpse of the protoconscious world without the
distorting effect of ordinary REM sleep.
In accordance with the proposed hypothesis, a high prevalence of
false awakenings could be expected in children, whose "REM sleep
machinery" might be less developed.
Gibson's hypothesis
Gibson's dream protoconsciousness
theory states that false awakening is shaped on some fixed patterns
depicting real activities, especially the day-to-day routine. False
awakening is often associated with highly realistic environmental
details of the familiar events like the day-to-day activities or
autobiographic and episodic moments.
Symptoms
Realism and non-realism
Certain aspects of life may be dramatized or out of place in false
awakenings. Things may seem wrong: details, like the painting on a wall,
not being able to talk or difficulty reading (reportedly, reading in
lucid dreams is often difficult or impossible).
Types
Celia Green suggested a distinction should be made between two types of false awakening:
Type 1
Type 1 is the more common, in which the dreamer seems to wake up, but
not necessarily in realistic surroundings; that is, not in their own
bedroom. A pre-lucid dream may ensue. More commonly, dreamers will
believe they have awakened, and then either genuinely wake up in their
own bed or "fall back asleep" in the dream.
A common false awakening is a "late for work" scenario. A person
may "wake up" in a typical room, with most things looking normal, and
realize they overslept and missed the start time at work or school.
Clocks, if found in the dream, will show time indicating that fact. The
resulting panic is often strong enough to truly awaken the dreamer (much
like from a nightmare).
Another common Type 1 example of false awakening can result in
bedwetting. In this scenario, the dreamer has had a false awakening and
while in the state of dream has performed all the traditional behaviors
that precede urinating – arising from bed, walking to the bathroom, and
sitting down on the toilet or walking up to a urinal. The dreamer may
then urinate and suddenly wake up to find they have wet themselves.
Type 2
The Type 2 false awakening seems to be considerably less common. Green characterized it as follows:
The subject appears to wake up in a realistic manner but to an atmosphere of suspense....
The dreamer's surroundings may at first appear normal, and they may
gradually become aware of something uncanny in the atmosphere, and
perhaps of unwanted [unusual] sounds and movements, or they may "awake"
immediately to a "stressed" and "stormy" atmosphere. In either case, the
end result would appear to be characterized by feelings of suspense,
excitement or apprehension.
Charles McCreery draws attention to the similarity between this description and the description by the German psychopathologist Karl Jaspers (1923) of the so-called "primary delusionary experience" (a general feeling that precedes more specific delusory belief). Jaspers wrote:
Patients feel uncanny and that there is something suspicious afoot. Everything gets a new meaning.
The environment is somehow different—not to a gross degree—perception
is unaltered in itself but there is some change which envelops
everything with a subtle, pervasive and strangely uncertain light.... Something seems in the air which the patient cannot account for, a distrustful, uncomfortable, uncanny tension invades him.
McCreery suggests this phenomenological similarity is not
coincidental and results from the idea that both phenomena, the Type 2
false awakening and the primary delusionary experience, are phenomena of
sleep. He suggests that the primary delusionary experience, like other
phenomena of psychosis such as hallucinations and secondary or specific
delusions, represents an intrusion into waking consciousness of
processes associated with stage 1 sleep. It is suggested that the reason for these intrusions is that the psychotic subject is in a state of hyperarousal, a state that can lead to what Ian Oswald called "microsleeps" in waking life.
Other researchers doubt that these are clearly distinguished types, as opposed to being points on a subtle spectrum.
Experimental descriptions
The clinical and neurophysiological descriptions of false awakening are rare. One notable report by Takeuchi et al., was considered by some experts as a case of false awakening. It depicts a hypnagogichallucination of an unpleasant and fearful feeling of presence in sleeping lab with perception of having risen from the bed. The polysomnography showed abundant trains of alpha rhythm on EEG (sometimes blocked by REMs mixed with slow eye movements
and low muscle tone). Conversely, the two experiences of FA monitored
here were close to regular REM sleep. Even quantitative analysis clearly
shows theta waves predominantly, suggesting that these two experiences
are a product of a dreaming rather than a fully conscious brain.
The clinical and neurophysiological characteristics of false awakening are
Three representations of an organic compound, 5α-Dihydroprogesterone (5α-DHP), a steroid hormone.
For molecules showing color, the carbon atoms are in black, hydrogens
in gray, and oxygens in red. In the line angle representation, carbon
atoms are implied at every terminus of a line and vertex of multiple
lines, and hydrogen atoms are implied to fill the remaining needed
valences (up to 4).
Organic chemistry is typically taught at the college or university level. It is considered a very challenging course but has also been made accessible to students.
Before the 18th century, chemists generally believed that compounds obtained from living organisms were endowed with a vital force that distinguished them from inorganic compounds. According to the concept of vitalism (vital force theory), organic matter was endowed with a "vital force". During the first half of the nineteenth century, some of the first
systematic studies of organic compounds were reported. Around 1816 Michel Chevreul started a study of soaps made from various fats and alkalis.
He separated the acids that, in combination with the alkali, produced
the soap. Since these were all individual compounds, he demonstrated
that it was possible to make a chemical change in various fats (which
traditionally come from organic sources), producing new compounds,
without "vital force". In 1828 Friedrich Wöhler produced the organic chemical urea (carbamide), a constituent of urine, from inorganic starting materials (the salts potassium cyanate and ammonium sulfate), in what is now called the Wöhler synthesis.
Although Wöhler himself was cautious about claiming he had disproved
vitalism, this was the first time a substance thought to be organic was
synthesized in the laboratory without biological (organic) starting
materials. The event is now generally accepted as indeed disproving the
doctrine of vitalism.
After Wöhler, Justus von Liebig worked on the organization of organic chemistry, being considered one of its principal founders.
In 1856, William Henry Perkin, while trying to manufacture quinine, accidentally produced the organic dye now known as Perkin's mauve. His discovery, made widely known through its financial success, greatly increased interest in organic chemistry.
A crucial breakthrough for organic chemistry was the concept of chemical structure, developed independently in 1858 by both Friedrich August Kekulé and Archibald Scott Couper. Both researchers suggested that tetravalent
carbon atoms could link to each other to form a carbon lattice, and
that the detailed patterns of atomic bonding could be discerned by
skillful interpretations of appropriate chemical reactions.
The era of the pharmaceutical industry began in the last decade of the 19th century when the German company, Bayer, first manufactured acetylsalicylic acid—more commonly known as aspirin. By 1910 Paul Ehrlich and his laboratory group began developing arsenic-based arsphenamine (Salvarsan) as the first effective medicinal treatment of syphilis, and thereby initiated the medical practice of chemotherapy. Ehrlich popularized the concepts of "magic bullet" drugs and of systematically improving drug therapies. His laboratory made decisive contributions to developing antiserum for diphtheria and standardizing therapeutic serums.
Early examples of organic reactions and applications were often found
because of a combination of luck and preparation for unexpected
observations. The latter half of the 19th century however witnessed
systematic studies of organic compounds. The development of synthetic indigo
is illustrative. The production of indigo from plant sources dropped
from 19,000 tons in 1897 to 1,000 tons by 1914 thanks to the synthetic
methods developed by Adolf von Baeyer. In 2002, 17,000 tons of synthetic indigo were produced from petrochemicals.
In the early part of the 20th century, polymers and enzymes were shown to be large organic molecules, and petroleum was shown to be of biological origin.
The multiple-step synthesis of complex organic compounds is called total synthesis. Total synthesis of complex natural compounds increased in complexity to glucose and terpineol. For example, cholesterol-related compounds have opened ways to synthesize complex human hormones
and their modified derivatives. Since the start of the 20th century,
complexity of total syntheses has been increased to include molecules of
high complexity such as lysergic acid and vitamin B12.
The total synthesis of vitamin B12 marked a major achievement in organic chemistry.
The discovery of petroleum and the development of the petrochemical industry spurred the development of organic chemistry. Converting individual petroleum compounds into types of compounds by various chemical processes led to organic reactions enabling a broad range of industrial and commercial products including, among (many) others: plastics, synthetic rubber, organic adhesives, and various property-modifying petroleum additives and catalysts.
The majority of chemical compounds occurring in biological
organisms are carbon compounds, so the association between organic
chemistry and biochemistry is so close that biochemistry might be regarded as in essence a branch of organic chemistry. Although the history of biochemistry
might be taken to span some four centuries, fundamental understanding
of the field only began to develop in the late 19th century and the
actual term biochemistry was coined around the start of 20th
century. Research in the field increased throughout the twentieth
century, without any indication of slackening in the rate of increase,
as may be verified by inspection of abstraction and indexing services
such as BIOSIS Previews and Biological Abstracts,
which began in the 1920s as a single annual volume, but has grown so
drastically that by the end of the 20th century it was only available to
the everyday user as an online electronic database.
Organic compounds were traditionally characterized by a variety
of chemical tests, called "wet methods", but such tests have been
largely displaced by spectroscopic or other computer-intensive methods
of analysis. Listed in approximate order of utility, the chief analytical methods are:
Nuclear magnetic resonance (NMR) spectroscopy
is the most commonly used technique, often permitting the complete
assignment of atom connectivity and even stereochemistry using correlation spectroscopy.
The principal constituent atoms of organic chemistry – hydrogen and
carbon – exist naturally with NMR-responsive isotopes, respectively 1H and 13C.
Elemental analysis: A destructive method used to determine the elemental composition of a molecule. See also mass spectrometry, below.
Mass spectrometry indicates the molecular weight of a compound and, from the fragmentation patterns,
its structure. High-resolution mass spectrometry can usually identify
the exact formula of a compound and is used in place of elemental
analysis. In former times, mass spectrometry was restricted to neutral
molecules exhibiting some volatility, but advanced ionization techniques
allow one to obtain the "mass spec" of virtually any organic compound.
Crystallography can be useful for determining molecular geometry
when a single crystal of the material is available. Highly efficient
hardware and software allows a structure to be determined within hours
of obtaining a suitable crystal.
Traditional spectroscopic methods such as infrared spectroscopy, optical rotation, and UV/VIS spectroscopy
provide relatively nonspecific structural information but remain in use
for specific applications. Refractive index and density can also be
important for substance identification.
Properties
The physical properties of organic compounds typically of interest
include both quantitative and qualitative features. Quantitative
information includes a melting point, boiling point, solubility, and
index of refraction. Qualitative properties include odor, consistency,
and color.
Melting and boiling properties
Organic compounds typically melt and many boil. In contrast, while
inorganic materials generally can be melted, many do not boil, and
instead tend to degrade. In earlier times, the melting point (m.p.) and
boiling point (b.p.) provided crucial information on the purity and
identity of organic compounds. The melting and boiling points correlate
with the polarity of the molecules and their molecular weight. Some
organic compounds, especially symmetrical ones, sublime. A well-known example of a sublimable organic compound is para-dichlorobenzene,
the odiferous constituent of modern mothballs. Organic compounds are
usually not very stable at temperatures above 300 °C, although some
exceptions exist.
Solubility
Neutral organic compounds tend to be hydrophobic; that is, they are less soluble in water than in organic solvents. Exceptions include organic compounds that contain ionizable groups as well as low molecular weightalcohols, amines, and carboxylic acids where hydrogen bonding occurs. Otherwise, organic compounds tend to dissolve in organic solvents. Solubility varies widely with the organic solute and with the organic solvent.
Various names and depictions for one organic compound
The names of organic compounds are either systematic, following
logically from a set of rules, or nonsystematic, following various
traditions. Systematic nomenclature is stipulated by specifications from
IUPAC (International Union of Pure and Applied Chemistry). Systematic nomenclature starts with the name for a parent structure
within the molecule of interest. This parent name is then modified by
prefixes, suffixes, and numbers to unambiguously convey the structure.
Given that millions of organic compounds are known, rigorous use of
systematic names can be cumbersome. Thus, IUPAC recommendations are more
closely followed for simple compounds, but not complex molecules. To
use the systematic naming, one must know the structures and names of the
parent structures. Parent structures include unsubstituted
hydrocarbons, heterocycles, and monofunctionalized derivatives thereof.
Nonsystematic nomenclature is simpler and unambiguous, at least
to organic chemists. Nonsystematic names do not indicate the structure
of the compound. They are common for complex molecules, which include
most natural products. Thus, the informally named lysergic acid diethylamide is systematically named
(6aR,9R)-N,N-diethyl-7-methyl-4,6,6a,7,8,9-hexahydroindolo-[4,3-fg] quinoline-9-carboxamide.
With the increased use of computing, other naming methods have
evolved that are intended to be interpreted by machines. Two popular
formats are SMILES and InChI.
Structural drawings
Organic molecules are described more commonly by drawings or structural formulas, combinations of drawings and chemical symbols. The line-angle formula
is simple and unambiguous. In this system, the endpoints and
intersections of each line represent one carbon, and hydrogen atoms can
either be notated explicitly or assumed to be present as implied by tetravalent carbon.
This
diagram shows 5 distinct structural representations of the organic
compound butane. The left-most structure is a bond-line drawing where
the hydrogen atoms are removed. The second structure shows the added
hydrogens depicted—the dark wedged bonds indicate the hydrogen atoms are
coming toward the reader, the hashed bonds indicate the atoms are
oriented away from the reader, and the solid (plain) bonds indicate the
bonds are in the plane of the screen/paper. The middle structure shows
the four carbon atoms. The 4th structure is a representation just
showing the atoms and bonds without three dimensions. The right-most
structure is a condensed structure representation of butane.
History
By 1880 an explosion in the number of chemical compounds being
discovered occurred, assisted by new synthetic and analytical
techniques. Grignard described the situation as "chaos le plus complet"
(complete chaos) due to the lack of convention, it was possible to have
multiple names for the same compound. This led to the creation of the Geneva rules in 1892.
The concept of functional groups is central in organic chemistry,
both as a means to classify structures and for predicting properties. A
functional group is a molecular module, and the reactivity of that
functional group is assumed, within limits, to be the same in a variety
of molecules. Functional groups can have a decisive influence on the
chemical and physical properties of organic compounds. Molecules are
classified based on their functional groups. Alcohols, for example, all
have the subunit C-O-H. All alcohols tend to be somewhat hydrophilic, usually form esters, and usually can be converted to the corresponding halides.
Most functional groups feature heteroatoms (atoms other than C and H).
Organic compounds are classified according to functional groups, e.g.,
alcohols, carboxylic acids, amines, etc. Functional groups make the molecule more acidic or basic due to their
electronic influence on surrounding parts of the molecule.
As the pKa (aka basicity) of the molecular addition/functional group increases, there is a corresponding dipole, when measured, increases in strength. A dipole directed towards the functional group (higher pKa
therefore basic nature of group) points towards it and decreases in
strength with increasing distance. Dipole distance (measured in Angstroms) and steric hindrance towards the functional group have an intermolecular and intramolecular effect on the surrounding environment and pH level.
Different functional groups have different pKa values and bond strengths (single, double, triple) leading to increased electrophilicity with lower pKa and increased nucleophile strength with higher pKa. More basic/nucleophilic functional groups desire to attack an electrophilic functional group with a lower pKa on another molecule (intermolecular) or within the same molecule (intramolecular). Any group with a net acidic pKa
that gets within range, such as an acyl or carbonyl group is fair game.
Since the likelihood of being attacked decreases with an increase in pKa, acyl chloride components with the lowest measured pKa values are most likely to be attacked, followed by carboxylic acids (pKa = 4), thiols (13), malonates (13), alcohols (17), aldehydes (20), nitriles (25), esters (25), then amines (35). Amines are very basic, and are great nucleophiles/attackers.
The aliphatic hydrocarbons are subdivided into three groups of homologous series according to their state of saturation:
alkanes (paraffins): aliphatic hydrocarbons without any double or triple bonds, i.e. just C-C, C-H single bonds
alkenes (olefins): aliphatic hydrocarbons that contain one or more double bonds, i.e. di-olefins (dienes) or poly-olefins.
alkynes (acetylenes): aliphatic hydrocarbons which have one or more triple bonds.
The rest of the group is classified according to the functional
groups present. Such compounds can be "straight-chain", branched-chain
or cyclic. The degree of branching affects characteristics, such as the octane number or cetane number in petroleum chemistry.
Both saturated (alicyclic)
compounds and unsaturated compounds exist as cyclic derivatives. The
most stable rings contain five or six carbon atoms, but large rings
(macrocycles) and smaller rings are common. The smallest cycloalkane
family is the three-membered cyclopropane ((CH2)3).
Saturated cyclic compounds contain single bonds only, whereas aromatic
rings have an alternating (or conjugated) double bond. Cycloalkanes do not contain multiple bonds, whereas the cycloalkenes and the cycloalkynes do.
Aromatic compounds
Benzene is one of the best-known aromatic compounds as it is one of the simplest and most stable aromatics.
Aromatic hydrocarbons contain conjugated double bonds. This means that every carbon atom in the ring is sp2 hybridized, allowing for added stability. The most important example is benzene, the structure of which was formulated by Kekulé who first proposed the delocalization or resonance
principle for explaining its structure. For "conventional" cyclic
compounds, aromaticity is conferred by the presence of 4n + 2
delocalized pi electrons, where n is an integer. Particular instability (antiaromaticity) is conferred by the presence of 4n conjugated pi electrons.
The characteristics of the cyclic hydrocarbons are again altered if
heteroatoms are present, which can exist as either substituents attached
externally to the ring (exocyclic) or as a member of the ring itself
(endocyclic). In the case of the latter, the ring is termed a heterocycle. Pyridine and furan are examples of aromatic heterocycles while piperidine and tetrahydrofuran are the corresponding alicyclic
heterocycles. The heteroatom of heterocyclic molecules is generally
oxygen, sulfur, or nitrogen, with the latter being particularly common
in biochemical systems.
Heterocycles are commonly found in a wide range of products
including aniline dyes and medicines. Additionally, they are prevalent
in a wide range of biochemical compounds such as alkaloids, vitamins, steroids, and nucleic acids (e.g. DNA, RNA).
Rings can fuse with other rings on an edge to give polycyclic compounds. The purine
nucleoside bases are notable polycyclic aromatic heterocycles. Rings
can also fuse on a "corner" such that one atom (almost always carbon)
has two bonds going to one ring and two to another. Such compounds are
termed spiro and are important in several natural products.
This swimming board is made of polystyrene; it is an example of a polymer.
One important property of carbon is that it readily forms chains, or
networks, that are linked by carbon-carbon (carbon-to-carbon) bonds. The
linking process is called polymerization, while the chains, or networks, are called polymers. The source compound is called a monomer.
Two main groups of polymers exist: synthetic polymers and biopolymers. Synthetic polymers are artificially manufactured, and are commonly referred to as industrial polymers. Biopolymers occur within a respectfully natural environment, or without human intervention.
Biomolecular chemistry is a major category within organic chemistry which is frequently studied by biochemists. Many complex multi-functional group molecules are important in living organisms. Some are long-chain biopolymers, and these include peptides, DNA, RNA and the polysaccharides such as starches in animals and celluloses in plants. The other main classes are amino acids (monomer building blocks of peptides and proteins), carbohydrates (which includes the polysaccharides), the nucleic acids (which include DNA and RNA as polymers), and the lipids. Besides, animal biochemistry contains many small molecule intermediates which assist in energy production through the Krebs cycle, and produces isoprene, the most common hydrocarbon in animals. Isoprenes in animals form the important steroid structural (cholesterol) and steroid hormone compounds; and in plants form terpenes, terpenoids, some alkaloids, and a class of hydrocarbons called biopolymer polyisoprenoids present in the latex of various species of plants, which is the basis for making rubber.
Biologists usually classify the above-mentioned biomolecules into four
main groups, i.e., proteins, lipids, carbohydrates, and nucleic acids.
Petroleum and its derivatives are considered organic molecules, which is
consistent with the fact that this oil comes from the fossilization of
living beings, i.e., biomolecules. See also: peptide synthesis, oligonucleotide synthesis and carbohydrate synthesis.
In pharmacology, an important group of organic compounds is small molecules,
also referred to as "small organic compounds". In this context, a small
molecule is a small organic compound that is biologically active but is
not a polymer. In practice, small molecules have a molar mass less than approximately 1000 g/mol.
Fullerenes
Fullerenes and carbon nanotubes, carbon compounds with spheroidal and tubular structures, have stimulated much research into the related field of materials science.
The first fullerene was discovered in 1985 by Sir Harold W. Kroto of
the United Kingdom and by Richard E. Smalley and Robert F. Curl Jr., of
the United States. Using a laser to vaporize graphite rods in an
atmosphere of helium gas, these chemists and their assistants obtained
cagelike molecules composed of 60 carbon atoms (C60) joined by single
and double bonds to form a hollow sphere with 12 pentagonal and 20
hexagonal faces—a design that resembles a football, or soccer ball. In
1996 the trio was awarded the Nobel Prize for their pioneering efforts.
The C60 molecule was named buckminsterfullerene (or, more simply, the buckyball) after the American architect R. Buckminster Fuller, whose geodesic dome is constructed on the same structural principles.
The number of possible organic reactions is infinite. However,
certain general patterns are observed that can be used to describe many
common or useful reactions. Each reaction has a stepwise reaction
mechanism that explains how it happens in sequence—although the detailed
description of steps is not always clear from a list of reactants
alone.
The stepwise course of any given reaction mechanism can be represented using arrow pushing
techniques in which curved arrows are used to track the movement of
electrons as starting materials transition through intermediates to
final products. The mechanism for certain organic reactions remain
subjects of ongoing debate and have not been fully elucidated.
Organic synthesis
A synthesis designed by E.J. Corey for oseltamivir (Tamiflu). This synthesis has 11 distinct reactions.
Synthetic organic chemistry is an applied science as it borders engineering, the "design, analysis, and/or construction of works for practical purposes". Organic synthesis of a novel compound is a problem-solving task, where a
synthesis is designed for a target molecule by selecting optimal
reactions from optimal starting materials. Complex compounds can have
tens of reaction steps that sequentially build the desired molecule. The
synthesis proceeds by utilizing the reactivity of the functional groups
in the molecule. For example, a carbonyl compound can be used as a nucleophile by converting it into an enolate, or as an electrophile; the combination of the two is called the aldol reaction.
Designing practically useful syntheses always requires conducting the
actual synthesis in the laboratory. The scientific practice of creating
novel synthetic routes for complex molecules is called total synthesis.
Strategies to design a synthesis include retrosynthesis, popularized by E.J. Corey,
which starts with the target molecule and splices it to pieces
according to known reactions. The pieces, or the proposed precursors,
receive the same treatment, until available and ideally inexpensive
starting materials are reached. Then, the retrosynthesis is written in
the opposite direction to give the synthesis. A "synthetic tree" can be
constructed because each compound and also each precursor has multiple
syntheses.
Catnip is a short-lived perennial
herb that grows between 30–100 cm (12–39 in) tall. It has square stems,
grayish canescent leaves that vary in shape and have serrated edges,
fragrant small bilabiate flowers arranged in raceme spikes, and produces small three-sided nutlets containing one to four seeds. It was described by Carl Linnaeus in 1753, with no subspecies but multiple botanical synonyms. Its name is derived from medieval Latin and reflects its historical association with cats and various traditional names dating back to medieval England.
Catnip is named for the intense attraction that about two-thirds of cats have to the plant due to the terpene nepetalactone. This chemical acts as a natural insect repellent and induces playful, euphoric behavior in cats. It is used in herbal teas for its sedative and relaxant properties; it is drought-tolerant and deer-resistant.
Description
Nepeta cataria is a short-lived perennial that grows 30 to 100 cm (12 to 39 in) tall, usually with several stems. Each of its stems is square in cross section, as typical of the mint family, and somewhat gray in color. It is a herbaceous plant that regrows from a taproot. It does not root deeply. Older plants tend to have more branches with particularly healthy plants becoming mound shaped.
The leaves are canescent in appearance, white in color due to being covered in fine hairs, especially so on the lower side of the leaves. They are attached in pairs to opposite sides of the stems. Leaf shapes vary from cordate (heart-shaped), deltoid (triangular), to ovate (egg-shaped). They are attached by leaf stems and have a length of 2 to 9 cm (0.8 to 3.5 in) and 0.6 to 6 cm (0.2 to 2.4 in) wide. The edges of the leaves are coarsely crenate to serrate, having a wavy, rounded edge to have asymmetrical teeth like those of a saw that point forward.
The flowers are in loose groups in an inflorescence. The lowest flowers are more widely spaced and at the end more tightly packed into a spike. The inflorescences lie at the end of the branches and may be 2 to 8 cm (0.8 to 3.1 in) long, with inconspicuous bracts. A single plant may produce several thousand flowers, but at any given time, less than 10% of them will be in full bloom. The flowers themselves are somewhat small and inconspicuous, but quite fragrant. They are bilaterally symmetrical and measure 10 to 12 mm (0.39 to 0.47 in) long. The petals are off-white to pink and usually dotted with purple-pink spots. They are bilabiate with the upper lip having two lobes and the lower one much wider with a scalloped edge.
The fruit is a nutlet
that is nearly triquetrous, three sided with sharp edges and concave
sides, and overall shaped like an egg. They measure approximately 1.7 by
1 mm (0.067 by 0.039 in). Each nutlet may contain between one and four seeds. They are dark reddish-brown in color with two white spots near the base.
Taxonomy
Nepeta cataria was one of the many species described by Linnaeus in 1753 in his landmark work Species Plantarum. He had previously described it in 1738 as Nepeta floribus interrupte spicatis pedunculatis (meaning "Nepeta with flowers in a stalked, interrupted spike"), before the commencement of Linnaean taxonomy. Catnip is classified in part of Nepeta in the Lamiaceae, commonly known as the mint family. It has no subspecies or varieties.
Synonyms
Nepeta cataria has 19 botanical synonyms, 16 of which are species. Only three are exactly equivalent to the current description of the species.
Names
The species name cataria means "of cats". It derives from the medieval Latin herba catti or herba cattaria used by medieval herbalists. The English common namecatnip is first recorded in 1775 in the colony of Pennsylvania, but now has worldwide usage. The variant catnep was also coined in the United States around 1806, but never became common elsewhere and is now very rarely used.
The first usage of catmint was in about 1300 in the form kattesminte. It continues to be used for Nepeta cataria, though it is also used for other species in the genus and the Nepeta as a genus. In medieval English it was also called cat-wort, but this ceased by about 1500.
Another name with a medieval origin was nep, neps, or nepe. Originating about 1475, it was more common but has become a regional name for catnip used in East Anglia.
In medieval England it was known by various names in botanical manuscripts. It was called calamentum minus and nasturcium mureligi. It was also called nepeta or variants, but other species or genera like the dead-nettles (Lamium) were also sometimes called this. It was also sometimes called collocasia, but this was more often applied to horse-mints especially Mentha longifolia.
Range and habitat
According to Plants of the World Online, the native range of catnip includes a large part of Eurasia. In Europe it is certainly native to the south around the Mediterranean
and in the east, but sources disagree on its native status in the north
in countries like the Baltic Countries, Germany, the Netherlands, and
United Kingdom. Around the Mediterranean it is identified as native in
Portugal, Spain, France, Corsica, Italy, Switzerland, the former
Yugoslavia, Albania, and Greece. In the East it is native to Bulgaria,
Romania, Ukraine, Belarus, European Russia, and the Caucasus. It is
generally agreed to be an introduced species in Scandinavia, Poland, and
may also grow in Ireland.
In Asia its range extends from Turkey into Syria, Lebanon, and
Iraq. Eastward it continues to Iran and Pakistan and the western
Himalayas, but no further into India. It is native to all of Central
Asia including Afghanistan, Kazakhstan, Kyrgyzstan, Tajikistan,
Turkmenistan, and Uzbekistan and also extends to western Siberia. Its
native status in China is disputed as it also is in the Russian Far East, Nepal, Korea, and Japan.
In Africa it may grow in Morocco, but this report is doubtful. It also grows as introduced species on the island of Java. In Australia it has been reported in the states of South Australia, New South Wales, Victoria, Queensland, and Tasmania. It grows on both the north and south islands of New Zealand, having been introduced there in 1870.
In North America it grows in Canada from the island of Newfoundland to British Columbia, but not in Labrador or the three northern Canadian territories. In the United States it is present in 48 states, only absent from Florida and Hawaii.
In South America it grows in many parts of Argentina as well as in Colombia.
It grows in a variety of soils from clay to sandy or even shallow
and rocky. It requires good drainage to prevent it from becoming
waterlogged.
Uses
The plant terpenoidnepetalactone is the main chemical constituent of the essential oil of Nepeta cataria. Nepetalactone can be extracted from catnip by steam distillation.
Cultivation
Nepeta cataria is cultivated as an ornamental plant for use in gardens. It is also grown for its attractant qualities to house cats and butterflies.
The plant is drought-tolerant and deer-resistant. It can be a repellent for certain insects, including aphids and squash bugs. Catnip is best grown in full sunlight and grows as a loosely branching, low perennial.
The cultivarNepeta cataria 'Citriodora', also known as lemon catmint, is known for the strong lemon-scent of its leaves.
Biological control
The iridoid that is deposited on cats who have rubbed themselves against the plants and scratched the surfaces of catnip and silver vine (Actinidia polygama) leaves repels mosquitoes. The compound iridodial, an iridoid extracted from catnip oil, has been found to attract lacewings that eat aphids and mites.
As an insect repellent
Nepetalactone is a mosquito and fly repellent. Oil isolated from catnip by steam distillation is a repellent against
insects, in particular mosquitoes, cockroaches, and termites.Research suggests that, while it may be a more effective spatial repellant than DEET, it is not as effective as SS220 or DEET when used on human skin.
Effect of ingestion on humans
Catnip has a history of use in traditional medicine for a variety of
ailments such as stomach cramps, indigestion, fevers, hives, and nervous
conditions. The plant has been consumed as a tisane, juice, tincture, infusion, or poultice, and has also been smoked. Its medicinal use has fallen out of favor with the development of modern medicine.
Effects
of catnip on most domestic cats include rolling, pawing, and frisking.
For cats not biologically affected by catnip, other plants that may
trigger a response include valerian root and leaves, silver vine, and Tatarian honeysuckle wood.
Catnip contains the feline attractant nepetalactone. N. cataria (and some other species within the genus Nepeta) are known for their behavioral effects on the cat family, including domestic cats and other species. Several tests showed that leopards, cougars, servals, and lynxes often reacted strongly to catnip in a manner similar to domestic cats. Lions and tigers may react strongly as well, but they do not react consistently in the same fashion.
With domestic cats, N. cataria is used as a recreational
substance for the enjoyment of pet cats, and catnip and catnip-laced
products designed for use with domesticated cats are available to
consumers. Common behaviors cats display when they sense the bruised
leaves or stems of catnip are rubbing on the plant, rolling on the
ground, pawing at it, licking it, and chewing it. Consuming much of the
plant is followed by drooling, sleepiness, anxiety, leaping about, and purring. Some cats growl, meow, scratch, or bite at the hand holding it. The main response period after exposure is generally between 5 and 15 minutes, after which olfactory fatigue usually sets in. About one-third of cats are not affected by catnip. The behavior is hereditary.
A study published in January 2021 suggests that felines are specifically attracted to the iridoids nepetalactone and nepetalactol, present in catnip and silver vine, respectively.
Cats younger than six months might not exhibit behavioral change to catnip. Up to a third of cats are genetically immune to catnip effects but may respond in a similar way to other plants such as valerian (Valeriana officinalis) root and leaves, silver vine or matatabi (Actinidia polygama), and Tatarian honeysuckle (Lonicera tatarica) wood.
