Word: Genus Welwitschia
Part of Speech: Noun
Explanation: The term "genus Welwitschia" refers to a specific group of plants within the family of Welwitschiaceae. It is the only type (or genus) in this family and includes a unique plant known as Welwitschia mirabilis. This plant is interesting because it has only two long leaves that grow continuously throughout its life and can live for a very long time, sometimes over a thousand years.
In summary, "genus Welwitschia" is a noun used in scientific contexts to refer to a unique and fascinating group of plants known for their adaptation to harsh environments.