Tree

===Food===
{{further|nut (fruit)|fruit}}

Trees are the source of many of the world's best known fleshy fruits. Apples, pears, plums, cherries and citrus are all grown commercially in temperate climates and a wide range of edible fruits are found in the tropics. Other commercially important fruit include dates, figs and olives. [[Palm oil]] is obtained from the fruits of the oil palm (''[[Elaeis guineensis]]''). The fruits of the cocoa tree (''[[Theobroma cacao]]'') are used to make [[cocoa solids|cocoa]] and chocolate and the berries of coffee trees, ''[[Coffea arabica]]'' and ''[[Coffea canephora]]'', are processed to extract the coffee beans. In many rural areas of the world, fruit is gathered from forest trees for consumption.<ref>{{cite web |url=http://www.fao.org/docrep/X5325e/x5325e0c.htm |title=Monetary valuation of tree-based resources in Zimbabwe |author=Campbell, B. |year=1993 |publisher=FAO: Forestry Department |access-date=13 September 2012 |archive-date=1 May 2013 |archive-url=https://web.archive.org/web/20130501225016/http://www.fao.org/docrep/X5325e/x5325e0c.htm |url-status=live }}</ref> Many trees bear edible nuts which can loosely be described as being large, oily kernels found inside a hard shell. These include [[coconut]]s (''Cocos nucifera''), [[Brazil nut]]s (''Bertholletia excelsa''), [[pecan]]s (''Carya illinoinensis''), [[Hazel|hazel nuts]] (''Corylus''), [[almond]]s (''Prunus dulcis''), [[walnut]]s (''Juglans regia''), [[pistachio]]s (''Pistacia vera'') and many others. They are high in nutritive value and contain high-quality protein, vitamins and minerals as well as dietary fibre.<ref>{{cite news |title=Walnuts are the healthiest nut, say scientists |url=https://www.bbc.co.uk/news/health-12865291 |newspaper=BBC News: Health |date=28 March 2011 |access-date=21 September 2014 |archive-date=24 September 2017 |archive-url=https://web.archive.org/web/20170924113046/http://www.bbc.co.uk/news/health-12865291 |url-status=live }}</ref> A variety of [[List of vegetable oils#Nut oils|nut oils]] are extracted by pressing for culinary use; some such as walnut, pistachio and hazelnut oils are prized for their distinctive flavours, but they tend to spoil quickly.<ref>{{cite book |url=https://archive.org/details/isbn_9780740769764 |url-access=registration |title=Things Cooks Love |author=Simmons, Marie |publisher=Andrews McMeel |year=2008 |page=[https://archive.org/details/isbn_9780740769764/page/295 295] |isbn=978-0-7407-6976-4}}</ref>

[[File:Maple syrup taps.jpg|thumb|left|Sugar maple (''[[Acer saccharum]]'') tapped to collect sap for [[maple syrup]]]]

In temperate climates there is a sudden movement of sap at the end of the winter as trees prepare to burst into growth. In North America, the sap of the sugar maple (''[[Acer saccharum]]'') is most often used in the production of a sweet liquid, [[maple syrup]]. About 90% of the sap is water, the remaining 10% being a mixture of various sugars and certain minerals. The sap is harvested by drilling holes in the trunks of the trees and collecting the liquid that flows out of the inserted spigots. It is piped to a sugarhouse where it is heated to concentrate it and improve its flavour. Similarly in northern Europe the spring rise in the [[Birch sap|sap]] of the silver birch (''Betula pendula'') is tapped and collected, either to be drunk fresh or fermented into an alcoholic drink. In Alaska, the sap of the sweet birch (''[[Betula lenta]]'') is made into a syrup with a sugar content of 67%. Sweet birch sap is more dilute than maple sap; a hundred litres are required to make one litre of birch syrup.<ref>{{cite web |url=http://www.alaskabirchsyrup.com/abbisy.html |title=About birch syrup |publisher=Alaska Wild Harvest |access-date=27 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120815013022/http://www.alaskabirchsyrup.com/abbisy.html |archive-date=15 August 2012 }}</ref>

Various parts of trees are used as spices. These include [[cinnamon]], made from the bark of the cinnamon tree (''[[Cinnamomum zeylanicum]]'') and [[allspice]], the dried small fruits of the pimento tree (''[[Pimenta dioica]]''). [[Nutmeg]] is a seed found in the fleshy fruit of the nutmeg tree (''[[Myristica fragrans]]'') and [[clove]]s are the unopened flower buds of the clove tree (''[[Syzygium aromaticum]]'').<ref name=spices/>

Many trees have flowers rich in [[nectar]] which are attractive to bees. The production of forest honey is an important industry in rural areas of the developing world where it is undertaken by small-scale beekeepers using traditional methods.<ref>{{cite web |url=http://www.tropicalforest.com/Tropical_Forest/Tropical_Forest_home.html |archive-url=https://web.archive.org/web/20111015230522/http://www.tropicalforest.com/Tropical_Forest/Tropical_Forest_home.html |archive-date=15 October 2011 |title=Honey |publisher=Tropical Forest |access-date=28 July 2012 |url-status=dead }}</ref> The flowers of the elder (''[[Sambucus]]'') are used to make [[elderflower cordial]] and petals of the plum (''[[Prunus]] spp.'') can be candied.<ref>{{cite web |url=http://extension.colostate.edu/topic-areas/yard-garden/edible-flowers-7-237/ |title=Edible flowers |author1=Newman, S. E. |author2=O'Connor, A. Stoven |date=November 2009 |publisher=Colorado State University Extension |access-date=28 July 2012 |archive-date=11 October 2015 |archive-url=https://web.archive.org/web/20151011151626/http://extension.colostate.edu/topic-areas/yard-garden/edible-flowers-7-237/ |url-status=live }}</ref> [[Sassafras]] oil is a flavouring obtained from distilling bark from the roots of the sassafras tree (''[[Sassafras albidum]]'').

The leaves of trees are widely gathered as fodder for livestock and some can be eaten by humans but they tend to be high in tannins which makes them bitter. Leaves of the curry tree (''[[Murraya koenigii]]'') are eaten, those of [[kaffir lime]] (''Citrus × hystrix'') (in [[Thai food]])<ref name=thaitravel>{{cite web |last=Loha-unchit |first=Kasma |title=Kaffir Lime: Magrood |work=Thai Food and Travel |url=http://www.thaifoodandtravel.com/ingredients/klime.html |access-date=16 May 2012 |archive-date=9 May 2019 |archive-url=https://web.archive.org/web/20190509021529/http://www.thaifoodandtravel.com/ingredients/klime.html |url-status=live }}</ref> and ''[[Ailanthus]]'' (in [[Korean food|Korean]] dishes such as [[bugak]]) and those of the European bay tree (''[[Laurus nobilis]]'') and the California bay tree (''[[Umbellularia californica]]'') are used for flavouring food.<ref name=spices>{{cite web |url=http://waynesword.palomar.edu/ecoph16.htm |title=Allspice, Bay Rum, Bay Leaves, Capers, Cloves, Cinnamon, Camphor, Witch Hazel & Nutmeg |last=Armstrong |first=Wayne P. |date=1 June 2012 |work=Wayne's Word |access-date=28 July 2012 |archive-date=10 August 2012 |archive-url=https://web.archive.org/web/20120810131037/http://waynesword.palomar.edu/ecoph16.htm |url-status=live }}</ref> ''[[Camellia sinensis]]'', the source of tea, is a small tree but seldom reaches its full height, being heavily pruned to make picking the leaves easier.<ref>{{cite web |url=http://www.upasitearesearch.org/tea-cultivation-practices/ |title=Tea cultivation and practices |publisher=Upasi Tea Research Foundation |access-date=13 September 2012 |archive-date=17 October 2012 |archive-url=https://web.archive.org/web/20121017032147/http://www.upasitearesearch.org/tea-cultivation-practices/ |url-status=live }}</ref>

[[Smoking (cooking)|Wood smoke]] can be used to preserve food. In the hot smoking process the food is exposed to smoke and heat in a controlled environment. The food is ready to eat when the process is complete, having been tenderised and flavoured by the smoke it has absorbed. In the cold process, the temperature is not allowed to rise above {{convert | 100 | °F | °C | abbr=on}}. The flavour of the food is enhanced but raw food requires further cooking. If it is to be preserved, meat should be [[Curing (food preservation)|cured]] before cold smoking.<ref>{{cite news |title=The rise and rise of smoking food |last=Mackenzie |first=Sophie |url=https://www.theguardian.com/lifeandstyle/wordofmouth/2012/jan/30/rise-of-smoking-food |newspaper=The Guardian |date=30 January 2012 |access-date=27 July 2012 |location=London |archive-date=4 March 2016 |archive-url=https://web.archive.org/web/20160304052854/http://www.theguardian.com/lifeandstyle/wordofmouth/2012/jan/30/rise-of-smoking-food |url-status=live }}</ref>