The Banana Flowers Are Falling Off

Inflorescence

• The trunk produces secondary stems called rachis. These are where the flowers are born. What is termed the "flower" is actually numerous components, covered by a purplish bract, which is a modified leaf. The bract rolls up to expose the true flowers. The entire inflorescence is both male and female and is technically unisexual. The sex is determined after flowering by whichever flowers abort. In good conditions, a bract rolls up to expose the flowers daily.

Female Flowers

• As the bract rolls up, the first tube-like white flowers are revealed. The first five to 15 rows are female with abortive male parts. Still more flowers appear, but they are sterile and are both male and female. The first set of female flowers develops into fruit. Their ovaries swell and become bananas over time. Meanwhile, the set of sterile female flowers drop off. They do not have the necessary parts to produce fruit, even if they were pollinated.

Male Flowers

• The male flowers develop with the second set of female flowers lower on the bract. They have long pollen-coated stamens flanked by slender anthers, which produce the pollen. Insects are the common pollinators; they push into the center of the anthers and contact the pollen. A sterile staminoide at the base of the arrangement of stamen and anthers gives pollinating insects a perch as they gather nectar. The insects move among both the male and female flowers, pollinating the females as they go. The males fall off the plant when pollination has been accomplished and leave a scar on the rachis.

The Fruit

• The fruiting stem only lives two to three years; during this time, it can produce many clusters of bananas. The bananas begin to form in summer and then over-winter. They begin to ripen in April or May. Bananas are technically a berry and start out green to ripen to yellow or red. The most commonly cultivated varieties are seedless, but wild types produce seed. Fruits are harvested while green and then allowed to ripen off the stalk.