BROMELIADS — FOSTER 357 



become succulent, but when the plant is attached to a tree in the jungle 

 the food comes from above, and the hard and wiry roots are used only 

 for holding fast. Many of the bromeliads are undoubtedly versatile 

 enough to get their food the easiest way, but the more highly epiphytic 

 types have specialized to such an extent and gone so long without root 

 feeders that they simply cannot stand 'Svet feet" or roots smothered 

 in a heavy soil, for they promptly rot at the base. 



Those epiphytic bromeliads which out in the jungle accumulate de- 

 cayed vegetable matter in the center cups must have rain water to make 

 the food soluble, and those bromeliads which have neither center cups 

 nor feeder roots, such as many Tillandsias, also need rain to help 

 assimilate their food from the dust particles of the air. But in the 

 absence of rain, the dew collected daily in the peltate scales that cover 

 their leaves enables them to live for months without rain, attached 

 to a limb or the perpendicular side of a rock in full sun ; thus they are 

 true xerophytes. 



Although Tillandsias such as T. usneoides and T. decomposita will 

 certainly grow profusely without the aid of roots or any visible supply 

 of food, the experiments that I have carried out and seen conducted 

 have convinced me beyond any doubt that most of the bromeliads must 

 have a source of food other than just air and rain. The plants will live 

 for some time without proper nourishment if not exposed to too much 

 sun, but they certainly will not thrive, especially if they are suspended 

 from wires as was done in an experiment in Brazil to prove the theory 

 that they need no food other than air and water. I have seen these 

 plants there. They hang on wires and hooks, hundreds of them, and, 

 yes, they were living — some of them — but they were gasping pitifully 

 for existence and were dying one by one. The only happy ones were 

 the exceptionally few types of Tillandsias that really can "do the im- 

 possible." Even pineapple plants were liung on wire, but I assure you 

 that they would never bear fruit. Each plant had literally to live on 

 itself, gi'adually getting smaller and finally drying up. It was a terrific 

 endurance test and, except for some of the orchids, I know of no other 

 plants that could have held on so long. 



In the field I have found isolated examples of "natural misplace- 

 ment" : pineapple plants and plants of Bromelia serra^ both terrestrial, 

 whose seeds undoubtedly were dropped by birds in the boots of a palm 

 high off the ground. However, these plants were not happy, nor were 

 they bearing fruit, but were gradually growing smaller. 



That terrestrial bromeliads also tend to feed through the leaves has 

 been shown by the commercial pineapple growers, who have found that 

 fertilizer thrown into the base of the lower leaves is more readily taken 

 up as nourishment and produces faster growth than when it is dis- 

 tributed only in the soil surrounding the plant. This is an illustra- 

 tion of the tendency of practically the entire family to be able to feed 



