This is a weedy annual of warmer regions that may originate from Eurasia, at least in the case of var. pilosa, which predominates in North America (FNA 25). E. pilosa was first recorded in Ky. during the 1920s (Anderson 1924; B). It has often been confused with pectinacea in southeastern states (e.g. compare state maps in K). Some colls. from Ky. still need rechecking. Compared to pectinacea (FNA 25), pilosa has panicle branches usually whorled at lower two nodes (versus single or paired), narrower spikelets (0.6-1.4 mm versus 1.2-2.5 mm), shorter lower glumes (0.3-0.8 mm versus 0.5-1.5 mm), and lemmas with less conspicuous nerves; 2n = 40 (versus 60).