Crazy Plants: Pineapple

A pineapple (Ananas comosus) that isn't fully ripe.

A flowering pineapple

The pineapple is a commonly eaten fruit, but few people have actually seen the plant from which that edible fruit comes. This is likely in part due to the fact that most pineapple eaten in developed countries is eaten in the canned form. For example, did you know that before becoming that fruit, a pineapple is a series of red flowers in need of pollination? This is thanks to the fact that pineapple the fruit is actual not a sinlge fruit, but a compound fruit made of a number of smaller fruits. Each flower on the inflorescence will become only a small section of the fully ripened pineapple of which we are so familiar. You can see where each flower was when looking at the compound fruit, as each of the honey comb-like sections on the exterior of the fruit represents what was once a flower. When cutting up a whole pineapple, you can also see the flower remnants in the form of withered stamens near the rind.

The pineapple is also worth note thanks to how it photosynthesizes. It uses a fairly unusual method known as Crassulacean Acid Metabolism or CAM. Plants that use this form of metabolism are best adapted for areas that can be rather dry. Instead of opening their stomate during the day to gather carbon dioxide, CAM plants open them during the night when less water vapor will evaporate. Carbon dioxide is then stored as an acid and used for photosynthesis during the day when stomata are closed. This form of photosynthesis is nor particularly efficient under moist, cool conditions, but when it's arid, nothing can beat a CAM plant. CAM plants don't include a great number of species compared to C3 plants (i.e. most plant species), but groups that photosynthesize this way include some of the bromeliads and orchids, as well as many succulents. CAM plants are not very well studied, and there's even the International Society of Crassulacean Acid Metabolism that is working on bettering our understanding the process.

A field of pineapple plants

In addition to its use as a food, pineapple has also been used as a folk remedy for a wide variety of illnesses. These include such varied problems as corns and warts to soars, scarlet fever, scurvy, sprains, bladder problems, and even venereal diseases. By the way, unripened pineapple is actually toxic. Those harvesting pineapple can become injured thanks to the methods of harvesting and a chemical known as bromelain. A secondary infection following injury has been termed pineapple estate pyosis. This toxicity is also part of why the fruit was so heavily used as a folk remedy, since the toxins act as a violent purgative. So, be sure to eat your pineapple when it's fully ripe.

If you have not yet had fresh pineapple, it's a real treat that's much better than canned. Just beware to eat it ripe and don't eat the core or rind.

Sources are Purdue University, Pima Community College, Purdue University again, International Society of Crassulacean Acid Metabolism, Newcastle University, and University of Nebraska-Lincoln. Images are from Wikimedia Commons under Creative Commons licenses: one, two, three.