damage and a tree can produce latex for over 20 years. Ecologically, this has the
great advantage that an area remains forested, with associated benefits of soil
stabilization, and it has helped to stop some Amazonian forests from being
exploited.
Resinsand similar aromaticcompounds come from many flowering plants,
especially trees and shrubs, and conifers. Traditionally, these have been used
extensively in perfumes and were believed to have healing and magical proper-
ties. They became used for religious and other ceremonies, e.g. frankincense
(Boswellia spp.), myrrh (Commiphora spp.), and other members of the
Burseraceae all used as incense. Other resins made fine varnishand lacquer and
are the base for paints, glues and some cosmetics and organic solvents such as
turpentine. Their value has sometimes led to their preservation along with asso-
ciated flora and fauna. Similarly, many dyes come from plants. These may
derive from leaves, roots, flowers, fruits or seeds and include our most ancient
dyes such as henna, derived from the leaves of the Asian Lawsonia inermis, and
woad from Isatis tinctoria. Many of these became associated with ceremonies.
Many soaps and detergents are made partially from plant oils, particularly the
oil palm Elaeis guineensis, and coconut, mixed with animal tallow.
Tanninsare dark phenolic compounds deriving from bark, leaves or other
parts of many trees such as oaks and are traditionally used to treat leather
rendering it more waterproof and keeping it flexible. Tannins in tea leaves give
tea its flavor.Drugs Some plants contain substances that affect the nervous system, either as stimu-
lants or depressants and these have been used for centuries, often in traditional
ceremonies. As they were introduced to temperate regions, by their nature they
became enormously desirable among wealthy people and at times commanded
high prices. The most important of these in commercial production today are
caffeine from tea and coffee, nicotine from tobacco and various medicinal drugs
(Topic J5) as well as alcohol considered in Topic N1. The most commercially
valuable is coffee deriving from species of Coffea, mainly Coffea arabicawhich
comes from Ethiopia originally, but is now planted throughout the tropics. It
requires adequate rainfall and is often grown in hilly districts. The markets were
controlled by Arab traders until the 17th century when it was planted elsewhere
and it is one of the most important export crops from South America. Tea,
Camellia sinensis, originally from China, was also much desired. Tea plantations
in India became a foundation of British occupation and high taxes on tea set by
Britain on exports to North America were one of the triggers for the American
war of independence.
Tobacco,Nicotiana tabacum, originates in the American tropics and is planted
mainly in America. It is a plant requiring a fertile soil which is depleted rapidly,
and tobacco production requires high inputs. It thrived on the newly cultivated
soil in southern North America. Medicinal drugs such as opiates from poppies
and some, mainly illegal, psychoactive drugs such as cannabis and coca derive
from plants.
Plants have been used ceremoniallysince paleolithic times. Although they may
have had uses as food, timber, medicine or narcotic drugs, certain individuals
were frequently singled out for different uses. This has had an effect on the
ecology of many regions of the world since certain plants have been preserved
at the expense of others and some owe their survival to such a role. The ginkgoPlants as
symbols
N4 – Plants for other uses 239