Jamieson, Fausset and Brown on Jonah 4:6

6. gourd--Hebrew, kikaion; the Egyptian kiki, the "ricinus" or castor-oil plant, commonly called "palm-christ" (palma-christi). It grows from eight to ten feet high. Only one leaf grows on a branch, but that leaf being often more than a foot large, the collective leaves give good shelter from the heat. It grows rapidly, and fades as suddenly when injured.

to deliver him from his grief--It was therefore grief, not selfish anger, which Jonah felt (see on Jon 4:1). Some external comforts will often turn the mind away from its sorrowful bent.