Cactus  (Melocactus glaucescens)

Areoles: in cacti, the felted or woolly, cushion-like structures from which spines grow, flowers develop and new stems arise.
Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
Hybridisation: cross-breeding with a different species.

1. IUCN Red List (February, 2003)
   www.redlist.org
   
2. Taylor, N.P. & Zappi, D.C. (in press) Cacti of Eastern Brazil. Royal Botanic Gardens, Kew.
   
3. CITES (February, 2003)
   www.cites.org
   
4. Hewitt, T. (1993) The Complete Book of Cacti and Succulents. Dorling Kindersley, London.