Editing Botany (section)

=== Medicine and materials ===
[[Phytochemistry]] is a branch of plant biochemistry primarily concerned with the chemical substances produced by plants during [[secondary metabolism]].{{sfn|Benderoth|Textor|Windsor|Mitchell-Olds|2006|pp = 9118–9123}} Some of these compounds are toxins such as the [[alkaloid]] [[coniine]] from [[conium|hemlock]]. Others, such as the [[essential oil]]s [[Peppermint#Oil|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 [[Papaver somniferum|opium poppies]]. Many [[medication|medicinal]] and [[recreational drugs]], such as [[tetrahydrocannabinol]] (active ingredient in [[Cannabis (drug)|cannabis]]), [[caffeine]], [[morphine]] and [[nicotine]] come directly from plants. Others are simple [[Derivative (chemistry)|derivatives]] of botanical natural products. For example, the pain killer [[aspirin]] is the acetyl [[ester]] of [[salicylic acid]], originally isolated from the [[Bark (botany)|bark]] of [[willow]] trees,{{sfn|Jeffreys|2005|pp = 38–40}} and a wide range of [[opiate]] [[analgesics|painkillers]] like [[diamorphine|heroin]] are obtained by chemical modification of [[morphine]] obtained from the [[opium poppy]].{{sfn|Mann|1987|pp = 186–187}} Popular [[stimulant]]s come from plants, such as [[caffeine]] from coffee, tea and chocolate, and [[nicotine]] from tobacco. Most alcoholic beverages come from [[fermentation (food)|fermentation]] of [[carbohydrate]]-rich plant products such as [[barley]] (beer), rice ([[sake]]) and grapes (wine).{{sfn|University of Maryland Medical Center|2011}} [[Native Americans in the United States|Native Americans]] have used various plants as ways of treating illness or disease for thousands of years.{{sfn|Densmore|1974}} This knowledge Native Americans have on plants has been recorded by [[Ethnobotany|enthnobotanists]] and then in turn has been used by [[Pharmaceutical industry|pharmaceutical companies]] as a way of [[drug discovery]].{{sfn|McCutcheon|Ellis|Hancock|Towers|1992}}

Plants can synthesise coloured dyes and pigments such as the [[anthocyanin]]s responsible for the red colour of [[red wine]], yellow [[Reseda luteola|weld]] and blue [[Isatis tinctoria|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 board]]s, [[papyrus]] and paper, [[vegetable oil]]s, [[epicuticular wax|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 [[charcoal#History|history]] as a metal-[[smelting]] fuel, as a filter material and [[activated carbon#Applications|adsorbent]] and as an artist's material and is one of the three ingredients of [[gunpowder]]. [[Cellulose]], the world's most abundant organic polymer,{{sfn|Klemm|Heublein|Fink|Bohn|2005}} can be converted into energy, fuels, materials and chemical feedstock. [[cellulose#products|Products made from cellulose]] include [[rayon]] and [[cellophane]], [[methyl cellulose|wallpaper paste]], [[Butanol fuel#Using Alternate Carbon Sources|biobutanol]] and [[nitrocellulose|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 [[biofuel]]s, important alternatives to [[fossil fuel]]s, such as [[biodiesel]].{{sfn|Scharlemann|Laurance|2008|pp = 52–53}} Sweetgrass was used by Native Americans to ward off bugs like [[mosquitoes]].{{sfn|Washington Post 18 Aug 2015}} These bug repelling properties of sweetgrass were later found by the [[American Chemical Society]] in the molecules [[phytol]] and [[coumarin]].{{sfn|Washington Post 18 Aug 2015}}