LIFE HISTORIES OF FAMILIAR PLANTS 



of into the soil as do ordinary roots. The plant 

 requires little or no moisture other than that 

 provided by the atmosphere, and flourishes well 

 on the piece of bark to which it chngs. Then, as 

 if to excel these novel efforts, it grows upside 

 down, pointing its leaves towards the ground with 

 its roots and bulbs turned upwards. If its position 

 is reversed to that of a normal plant, it soon 

 readjusts itself to its topsy-turvy attitude, and 

 in this position flowers and produces its seeds. 

 This orchid is known by the name Cattleya citrina 

 and hails from Mexico ; but what benefits it de- 

 rives from its novel manoeuvres the plant seems 

 to understand best. 



In its natural habitat it grows adhering to the 

 bark on the branches of trees and sometimes to 

 rocks, and probably by turning down its foliage 

 and flowers in this unusual fashion, it derives shade 

 beneath the boughs or the overhanging rocks. 

 Again (as another suggestion), the plant seems 

 wonderfully adapted for throwing off water. 

 Water poured on from above is immediately 

 conducted to the ground ; the flower refuses water 

 in the same manner. 



Now these orchids, like the cacti, being subjected 

 to torrential rains alternating with long periods of 

 drought, their thick and fleshy leaves — held more 

 or less closely together — retain water within their 

 tissues and bulbs, while the roots are continually 

 absorbing moisture from the atmosphere. Thus 

 the dry season is met. When the wet period sets 

 in, seeing that the plant is not rooted in the soil, 



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