Heteropogon contortus (spear grass).
H. contortus is native to Africa, temperate and tropical Asia, Australasia and southwestern Europe, and is naturalized in southern USA, Mexico, the Caribbean, Central and South America (USDA-ARS, 2017). It is reported as naturalized in Hawaii by USDA-ARS (2017) but according to University of Hawaii (2009), it is not clear whether H. contortus is indigenous to Hawaii or a Polynesian introduction. USDA-ARS (2017) and Baldwin et al. (2012) report H. contortus as an alien species in California, USA, but according to Calflora (2017), it is native in California.