Indian grass
/ˌɪndɪən ˈɡrɑːs/ /ˌɪndɪən ˈɡras/noun
1 Angling. Silkworm gut used for making lines. Now historical and rare.
2Chiefly US. Any of various grasses; especially Sorghastrum nutans, which is one of the dominant grasses of the North American prairies.
Origin
Late 17th century; earliest use found in The London Gazette. From Indian + grass.