If you are out hiking in March in the tropics, be sure to watch for a vine growing along the trail. There are small green leaves with small yellow flowers. Look closer and you might find a Momordica balsamina. It is a tendril-bearing annual vine native to the tropical regions of Africa, introduced and invasive in Asia, Australia, and Central America, including Mexico. It has pale yellow, deeply veined flowers and round, somewhat warty, bright orange fruits, or “apples”. When ripe, the fruits burst apart, revealing numerous seeds covered with a brilliant scarlet, extremely sticky coating. The balsam apple was introduced into Europe by 1568 and was used medicinally to treat wounds. In 1810, Thomas Jefferson planted this vine in his flower borders at Monticello along with larkspur, poppies, and nutmeg. The outer rind and the seeds of the fruit are said to be poisonous. Momordica balsamina and the related Momordica charantia share some common names: African cucumber, balsam apple, and balsam pear. Other names for M. balsamina are balsamina or southern balsam pear. It is known in Africa under a broad range of names, e.g. in Mozambique as cacana and in South Africa as nkaka.
I have tasted the fatty covering of the seeds and found it to be sweet. I did not die from the poison.