The yellow bristle grass (Setaria pallide-fusca) belongs to Poaceae (the Grass family). It is an annual herb that is widely distributed in tropical and subtropical regions of the world, including various parts of Japan. This herb grows on roadsides and wastelands, and is usually about 30 cm in height. The stems stand upright and are clumping, with linear lanceolate leaves alternating. The leaves and petioles are hairless. The flowering spikes are purple-tinted brown, smaller than "Yellow foxtail" (Setaria glauca), about 2 to 3 cm long, and borne at the tip of the stem from August to October.