Tell the attribute of the weeds in image no.2377988.
attribute of the weeds refers to OBJ_CLASS = 'weeds'; image no.2377988 refers to IMG_ID = 2377988
SELECT T2.ATT_CLASS FROM IMG_OBJ_att AS T1 INNER JOIN ATT_CLASSES AS T2 ON T1.ATT_CLASS_ID = T2.ATT_CLASS_ID INNER JOIN IMG_OBJ AS T3 ON T1.IMG_ID = T3.IMG_ID INNER JOIN OBJ_CLASSES AS T4 ON T3.OBJ_CLASS_ID = T4.OBJ_CLASS_ID WHERE T4.OBJ_CLASS = 'weeds' AND T1.IMG_ID = 2377988