The third stanza of "Strange Fruit" provides a final view of the scene that was described in the previous stanzas. The "strange fruit" featured in the lyrics are the bodies of African-Americans that are "hanging from the poplar trees."
As the bodies hang in the "southern breeze" and begin to decay under the heat and humidity of the surroundings, scavengers like crows will begin to tear into the flesh and eat the carrion. The sun and wind will speed the evaporation of some bodily fluids but internal moisture will continue to draw animals to the meat of the bodies. If the bodies are left hanging long enough, decay and the separation of the meat from bones by scavenging animals will eventually cause the remains to drop from the trees.
After following a very predictable rhyming pattern, with each pair of lines rhymed, through the entire lyric, the final two lines do not rhyme. The jarring effect of that sound instead of the anticipated rhyme creates a final impact and reinforces the horror of the scene.