This is a particularly complicated poem, starting with the headnote: the Fifth Day of the Fifth Month was conventionally a time of heavy rain, so the poet staring at the iris is also staring at rain (tears) dripping onto the iris. There is also a play-on-words with ne being both ‘root’ and ‘sound (of weeping)’.

So, the poem says, “When I sit here gazing at the (rain dripping on the) iris in the eaves, (in my misery I weep) and all I hear is the sound (of my sobs), with my sleeves trailing like (iris) roots.” It is a combination of images of dejection.