- Species (Wikipedia)
In biology, a species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour, or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined.
- Hedera helix (Wikipedia)
Hedera helix, the common ivy, European ivy, or just ivy, is a species of flowering plant in the family Araliaceae. It is native to most of Europe and parts of western Asia. Ivy is a clinging evergreen vine that grows on tree trunks, walls, and fences in gardens, waste spaces, and wild habitats. Ivy is popular as an ornamental plant, but escaped plants have become naturalised outside its native range. Ivy has considerable cultural significance and symbolism.