Where does “bristlegrass” come from?

bristlegrass (English) comes from English grass, from Middle English gras, from Old English græs, from Proto-West Germanic gras, from Proto-Germanic grasą, from Proto-Indo-European ǵʰreh₁- — to become green, grow; to grow; to green, to grow.

bristlegrass (English): Any of various grasses of the genus "Setaria"

Definitions

  1. Any of various grasses of the genus "Setaria"

Ancestry of “bristlegrass”, step by step

bristlegrass traces back through two separate lines of ancestry.

via English grass

StepLanguageWordMeaning
1EnglishgrassAny plant of the family Poaceae, characterized by...
2Middle EnglishgrasA grass; Any plant; especially a herbaceous one;...
3Old Englishgræsgrass
4Proto-West Germanicgrasgrass
5Proto-Germanicgrasągrass
6Proto-Indo-Europeanǵʰreh₁-to become green, grow; to grow; to green, to grow

via English bristle

StepLanguageWordMeaning
1EnglishbristleA stiff or coarse hair; The hairs or other...
2Middle Englishbristil
3Old Englishbristla bristle
Every word from Proto-Indo-European ǵʰreh₁-Every word from Proto-Germanic grasąEvery word from Proto-West Germanic gras