422 



GARDENERS' CHRONICLE 



of the rest of the leaves. (This purple is of a hue similar 

 to that found in the leaves of many of the CommcHnacca, 

 such as Tradcscantia regince and Rhoco discolor.) From 

 the center of these rosettes of green and purple arise the 

 bract leaves of bright scarlet which produces an effect 

 that is startling in its uniqueness. To find combinations 

 of color in any way comparable to this one is restricted 

 to the Bromcliacccc. 



Botanical interest in these plants centers largely in 

 their adaptations to environment. They are mostly na- 

 tives of tropical America, and many of them are epi- 

 phvtes. In a large number of species the leaves are ar- 

 ranged in rosettes in such a way that their bases form 

 cup-like reservoirs of water. Considerable quantities 

 may be held in this way, as those who have inadvertently 

 tipped over such plants as .Echiiica can testify. I have 

 measured the amount of water held in the leaf bases of a 

 single rosette of JEchmca piiicliana and found it to be 

 almost one quart. 



This water storage apparently has an important func- 

 tion in the economy of the plants. Growing on trees, as 

 many do. the ojiportunities for absorption of water by 

 the roots is somewhat limited, but this is counterbalanced 

 by the ability of the leaves to catch water and to absorb 

 it by means' of thin-walled cells that occur at the base 

 of the leaves. It has also been suggested that the plants 

 obtain some of their nitrogen from insects, and debris 

 of various kmds that fall into the reservoirs, which de- 

 cay and form food substances that can be absorbed by 

 the thin-walled cells. 



The water in the petiole bases frequently has other 

 plants growing in it and Darwin, in his fascinating 

 Insectivorous Plants, quotes from Gardner"s Travels m 

 the Interior of Brazil concerning a species of I'.ladder- 

 wort, Utricularia nelumbifoiia, which grows exclusivelv 

 in the leaf bases of certain Bromeliads : 'Tt is only to 

 be found growing in the water which collects_ in the 

 bottom of the leaves of a large Tillandsia, that inhabits 

 abundantlv an arid rockv part of the mountain, at an 

 elevation of about 5,000 feet above the level of the sea 

 Besides the ordinary method by seed, it propagates itself 

 by runners, which 'it throws out from the base of the 

 flower-stem : this runner is always found directing itself 

 towards the nearest Tillandsia. when it inserts its point 

 into the water and gives origin to a new plant, which 

 in its turn sends out another shoot. In this manner 1 

 have seen not less than six plants united." Other author- 

 ities state Bromeliads and other epiphytes are themselves 

 overgrown bv mosses and lichens. Thus we have the 

 Bromeliads growing on trees, although not parasitically, 

 be it remarked, and" other plants, in turn, on them, whicli 

 calls to mind the oft quoted lines of ."^wift; 

 "So, naturalists observe, a flea 

 Has smaller fleas that on him prey: 

 And these have smaller still to bite ■em: 

 .\nd so proceed ad infiuitum." 



The leaf cuticle of the Bromeliads is usually greatly 

 thickened and often covered with scurfy scales which 

 serve to prevent evaporation and thus tide the plants 

 over hot dry periods. That it is effective I have seen 

 proven bv rosettes of Crxptanthus. which have been 

 broken off, or fallen off, the parent plant and thrown 

 under the bench. Here, without roots, they kept m 

 good condition for a considerable time, although there 

 were steam pipes just above them and such watering as 

 they received was spasmodic and accidental. 



Some of the Bromeliads may be considered as true 



-xerophvtic plants, and as such can perhaps best be cared 

 for in the Cactus house rather than in one wdrere more 

 humid conditions prevail. Examples of plants in this 

 group are D\ckia of various species, Bromclia lasiantha, 

 and Hechtia argentca. The latter is a striking olaject, 

 forming rosettes which may be a foot or more in diameter, 

 formed of very stiff, spiny and recurved leaves which 

 are silvery and shining. In this group belongs Puya 

 chilensis, one of the hardiest of the family, which can 

 be grown outdoors with Winter protection in favored 

 sections in England. 



The xeroph}'tic nature of many of the Bromeliads may 

 account in a large measure for the tolerance they exhibit 

 when grown in the arid air of the ordinary dwelling house. 



It is amongst these xerophytic types that we find pro- 

 tective spines most highly developed. In some species ii 

 almost seems that they are designed as revengeful 

 weapons as well as a means of defense. Thus in Ananas 

 niacrodontes. for example, the stout formidable spines 

 at the tips of the leaves point outwards whilst those at 

 the ba'-c point inwards. Therefore, it would appear that 

 should any browsing animal have the temerity to at- 

 tempt to make a meal from this particular species, he 

 would be warned by the out-pointing spines and chastised 

 on his retreat b\- the in-pointing ones. Bromclia pingnin, 

 a species that attains a height of about four feet, has 

 similar vicious proclivities and is said to be used as a 

 hedge in the West Indies. After seeing it one can 

 imagine that such a hedge would be impenetrable. In 

 manv S|)ecies the spines form a distinct decorative fea- 

 ture, esjieciallv when they are colored, as in ^Hchmea 

 piucliaihi. which has prominent brown spines. 



The only plant of prime economic importance in this 

 family is the pineapple. Ananas satiius. Many gardeners, 

 especially those with English training, whose experience 

 extends back a period of years, will remember when this 

 delicious fruit was an important product under glass 

 on many mMvate estates in northern climes. But with 

 the advent of improved methods of transportation, the 

 pine "pit" has lost its importance and we rely instead 

 on fruit shipped from some center where it is grown in 

 the open, or on the canned product. To many the latter 

 is preferable, as the fresh fruit that we receive in northern 

 markets is shipped before it is properly ripe and is none 

 too palatable. It is worth while to grow a few pine- 

 apples in pots, if only for the purpose of surpri.smg 

 casual visitors, manv of whom have a vague notion that 

 "pineapples grow on trees somewhere in the South." 

 There are tw-o variegated varieties of the pineapple that 

 are worth growing for their foliage, and these, if given 

 reasonably good treatment, will often reward the grower 

 with a fruit. The best form. I think, is Ananas satnnts 

 var. varic'^atus. in which the center of the leaf is green 

 and the niargins of cream or yellow. In A. sativiis var. 

 porteanus this coloring is reversed with the yellow m 

 the center. In addition the leaves are sometimes striped 

 or suffused w-ith red. 



The other species in this family that enters into com- 

 merce for reasons unconnected with its ornamental ap- 

 pearance is Tillandsia iisneoides. the well-known Spanish 

 Moss which is used for .stuffing mattresses. This is a 

 true "air plant" and bedecks trees and telegraph wires in 

 ],arts of the south. In general appearance it is strangely 

 similar to the lichen Vsnea. wdiich is to be seen hanging 

 from the branches of the firs and spruces in the north. 

 The Spanish :Moss lives under greenhouse conditions, 

 provided a warm humid atmosphere is maintained, even 

 when suspended on nothing more nutritious than copper 

 wire. 



