Amanita sinicoflava, the mandarin yellow ringless amanita, is an inedible species of fungus in the large genus Amanita. Found in North America, the fungus was described as new to science in 1998 by mycologist Rodham Tulloss. The type collections were made in Sussex County, New Jersey. The mushroom grows in sandy soil under Quercus, Pinus rigida, Acer rubrum, Quercus alba, and Quercus velutina. Fruitbodies have yellow-olivaceous or olive-tan caps that measure 2.5–7 cm (1.0–2.8 in) in diameter. There are grooves on the cap margin that extend about 40% of the distance from the margin to the apex. The spores are spherical or nearly so, typically measuring 9.1 to 12.2 micrometres (0.36 to 0.48 mils) by 8.4 to 11.5 micrometres (0.33 to 0.45 mils). The white stipe is ornamented with slightly dark