Question: Which popular stimulants come from plants?
About the article "Botany", section "Medicine and materials".

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Seed germination of parasitic plants occurs in a variety of ways.
These means can either be chemical or mechanical and the means used by seeds often depends on whether or not the parasites are root parasites or stem parasites.
Both root and stem parasitic plants have evolved to use one or more means of finding their hosts in order to germinate.
Most parasitic plants need to germinate in close proximity to their host plants because their seeds are limited in the amount of resources necessary to survive without nutrients from their host plants.
Resources are limited due in part to the fact that most parasitic plants are not able to use autotrophic nutrition to establish the early stages of seeding.
Root parasitic plant seeds tend to use chemical cues for germination.
In order for germination to occur, seeds need to be fairly close to their host plant.
For example, the seeds of the parasitic plant Witchweed ("Striga asiatica") need to be within 3 to 4 millimeters (mm) of its host in order to pick up chemical signals in the soil to signal germination.
This range is important because "Striga asiatica" will only grow about 4 mm after germination.
Chemical compound cues sensed by parasitic plant seeds are from host plant root exudates that are leached in close proximity from the host’s root system into the surrounding soil.
These chemical cues are a variety of compounds that are unstable and rapidly degraded in soil and are present within a radius of a few meters of the plant exuding them.
Parasitic plants germinate and follow a concentration gradient of these compounds in the soil toward the host plants if close enough.
These compounds are called strigolactones.
Strigolactone stimulates ethylene biosynthesis in seeds causing them to germinate.
There are a variety of chemical germination stimulants.
Strigol was the first of the germination stimulants to be isolated.
It was isolated from a non-host cotton plant and has been found in true host plants such as corn and millets.
The stimulants are usually plant specific, examples of other germination stimulants include sorgolactone from sorghum, orobanchol and alectrol from red clover, and 5-deoxystrigol from "Lotus japonicas".
Strigolactones are apocarotenoids that are produced via the carotenoid pathway of plants.
Strigolactones and mycorrhizal fungi have a relationship in which Strigolactone also cues the growth of mycorrhizal fungus.
Stem parasitic plants unlike most root plants germinate using the resources inside its endosperm and are able to survive for a small amount of time.
An example, Dodder ("Cuscuta" spp.)
is a parasitic plant whose seed falls to the ground and may remain dormant for up to five years before it is able to sense a host plants nearby.
Using the resources in the seed endosperm, Dodder is able to germinate.
Once germinated, the plant has 6 days to find and establish a connection with its host plant before its resources run out.
Dodder seeds germinate above ground and then the plant sends out stems in search of its host plant reaching up to 6 cm before it dies.
It is believed that the plant uses two methods of finding a host.
The stem is able to pick up its host plant’s scent whereby it then is able to orient itself in the direction of its host.
Scientists used volatiles from tomato plants (α-pinene, β-myrcene, and β-phellandrene) to test the reaction of C. "pentagona" and found that the stem will oriented itself in the direction of the odor.
Some studies suggest that by using light reflecting from nearby plants dodders are able to select host with higher sugar because of the levels of chlorophyll in the leaves.
Once Dodder finds its host, it wraps itself around the host plants stem.
Using adventitious roots, Dodder taps into the host plant’s stem and creates a haustorium, which is a special connection into the host plant vascular tissue.
Dodder makes several of these connections with the host as it moves up the plant. 
Phytochemistry is a branch of plant biochemistry primarily concerned with the chemical substances produced by plants during secondary metabolism.
Some of these compounds are toxins such as the alkaloid coniine from hemlock.
Others, such as the essential oils peppermint oil and lemon oil are useful for their aroma, as flavourings and spices (e.g., capsaicin), and in medicine as pharmaceuticals as in opium from opium poppies.
Many medicinal and recreational drugs, such as tetrahydrocannabinol (active ingredient in cannabis), caffeine, morphine and nicotine come directly from plants.
Others are simple derivatives of botanical natural products.
For example, the pain killer aspirin is the acetyl ester of salicylic acid, originally isolated from the bark of willow trees, and a wide range of opiate painkillers like heroin are obtained by chemical modification of morphine obtained from the opium poppy.
Popular stimulants come from plants, such as caffeine from coffee, tea and chocolate, and nicotine from tobacco.
Most alcoholic beverages come from fermentation of carbohydrate-rich plant products such as barley (beer), rice (sake) and grapes (wine).
Plants can synthesise useful coloured dyes and pigments such as the anthocyanins responsible for the red colour of red wine, yellow weld and blue woad used together to produce Lincoln green, indoxyl, source of the blue dye indigo traditionally used to dye denim and the artist's pigments gamboge and rose madder.
Sugar, starch, cotton, linen, hemp, some types of rope, wood and particle boards, papyrus and paper, vegetable oils, wax, and natural rubber are examples of commercially important materials made from plant tissues or their secondary products.
Charcoal, a pure form of carbon made by pyrolysis of wood, has a long history as a metal-smelting fuel, as a filter material and adsorbent and as an artist's material and is one of the three ingredients of gunpowder.
Cellulose, the world's most abundant organic polymer, can be converted into energy, fuels, materials and chemical feedstock.
Products made from cellulose include rayon and cellophane, wallpaper paste, biobutanol and gun cotton.
Sugarcane, rapeseed and soy are some of the plants with a highly fermentable sugar or oil content that are used as sources of biofuels, important alternatives to fossil fuels, such as biodiesel.
Leibenstein has used these 2 terms stimulants and shocks in his theory quite often.
He defines stimulant as any event that changes the value of a variable away from its equilibrium value so that due to this event there is an initial increase in the per capita income.
Shock on the other hand has been defined by Leibenstein as any event external to the system due to which per capita income is reduced initially.
Now in underdeveloped economies shocks are more powerful than stimulants so what should be done in such a scenario is that the levels of incomes should be risen to such an extent that stimulants become stronger than shocks and the growth in incomes becomes self-sustaining. 
Other research has been done on the chemical components extracted from the pod surface of "C. scarabaeoides" and compared with that of cultivated pigeonpea.
The β-carophyllene and guaiene that is emitted from cultivated pigeonpea, which attracts "H. armigera", was found to be absent in "C. scarabaeoides".
Acetone that was extracted from the pod surface of pigeonpea was found to stimulate larval feeding, where in "C. scarabaeoides" the extracts did not possess this characteristic.
The water extracted from the pods of both pigeonpea and "C. scarabaeoides" showed greater antifeedant activity in that of "C. scarabaeoides".
For scientists and breeders, being able to identify feeding stimulants associated with host plants and related insect pests allows for the selection of less susceptible genotypes during hybridization 
  Alcohol – Euphoria has been reported during the first 10–15 minutes of alcohol consumption  Passion Flower ("Passiflora incarnata") – Widely used as a sedative that has calming effects on the nervous system and acts as a sleep aid.
One harmala alkaloid present in this herb in the form of harmine is thought to induce meditative and euphoric effects.
Catnip – Contains a sedative known as nepetalactone that activates opioid receptors.
It elicits sniffing, licking, chewing, head shaking, rolling, and rubbing in cats, which are indicators of pleasure.
Catnip does not, however, induce the same response in human beings.
Cannabis – Tetrahydrocannabinol, the main psychoactive ingredient in the Cannabis plant has both stimulant and depressant properties but is commonly known to induce euphoria  Stimulants – Psychomotor stimulants are known to suppress locomotor activity (the subject becomes hypoactive) at therapeutic doses.
But are known to stimulate movement and hyperactivity in higher doses.
Euphoria can be produced by stimulants at any dose, but are more commonly seen when taken in higher doses.
Euphoria caused by stimulants is most often expressed by excessive talking, heighten levels of energy, and a reduced appetite (anorexia).
Amphetamines are the best known drugs in this category, which also include drugs like cocaine and methylphenidate.
MDMA – MDMA, also known as "ecstasy" and MDEA ("eve") are euphoriant drugs that induce "short-term feelings of euphoria, rushes of energy, and increased tactility" and are popular amongst young adults.
Opium – Opium and its derivatives morphine and codeine are drugs "derived from the unripe seedpods of the opium poppy produces drowsiness and euphoria and reduces pain"  Corticosteroids - Corticosteroids may produce a feeling of inappropriate well-being ("steroid euphoria") in some patients when taken for allergies and chronic obstructive lung disease.
Rome and Graceland have graded the psychiatric symptoms of corticosteroid excess, with mild euphoria in Grade 1, and heightened euphoria (effusive, expansive and hypomanic behavior) in Grade 2.