In general usage the word indigen is treated as a variant of the word indigene, meaning a native.
However, it was used in a strictly botanical sense for the first time in 1918 by Liberty Hyde Bailey ((1858âÂÂ1954) an American horticulturist, botanist and cofounder of the American Society for Horticultural Science) and described as a plant
<blockquote> " of known habitat ".
</blockquote> Later, in 1923, Bailey formally defined the indigen as:
<blockquote> " ... a species of which we know the nativity, - one that is somewhere recorded as indigenous. "</blockquote> The term was coined to contrast with cultigen which he defined in the 1923 paper as: <blockquote> " ... the species, or its equivalent, that has appeared under domestication, â the plant is cultigenous."</blockquote>