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Which plants contain caffeine?
The following table shows the eight major sources of caffeine...
Tea
Leaf, bud
3.5
India, China
Tea
(Camellia sinensis)
Cacao
Seed
0.03
West Africa, Brazil
Cocoa and
(Theobroma cacao)
chocolate products
Cola nut
Seed
1.5
West Africa
Chewing cola nuts
(Cola acuminata,
and cola tree
Cola nitida)
Mate
Leaf
<0.7
South America
Yerba mate
(Ilex paraguariensis)
Yaupon
Leaf, berry
(unknown)
(not cultivated)
Cassina
(Ilex cassine,
Ilex vomitoria)
Guarana
Seed
>4
Brazil
Soft drinks and
(Paulinia capana)
guarana bars
Yoco
Bark
2.7
South America
Yoco tea
(Paulliniayoco)
Two images of Coffea arabica,
whose berries are responsible for 75% of the world's coffee consumption
The table is by no means definitive. There are
around twenty-five species of the coffee shrub, (genus Coffea),
including liberica, which is larger than the two commercial species
above, and is indeed currently being cultivated in Africa. Coffea stenophylla
is reported to be superior to arabica in taste, but the crop requires
a longer time period to reach maturity, so commercial availability of the
plant is extremely limited.
Why do plants contain caffeine? It gives humans a buzz... but why did plants evolve the ability to produce caffeine in the first place?
Competition? Caffeine
is not the only stimulant alkaloid which is produced by plants and consumed
for the 'kick'...
Images used without permission from
the following sources:
Left hand image (also title page
image) Biological Sciences Review
Vol.10 No.2 November 1997 p.40
Right hand image
Photo by Thomas Schoepke, from www.plant-pictures.com
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