ABSORBING HAIRS 



75 



has less highly specialised hairs. Water-absorbing hairs 

 also line similar leaf cisterns in the Javan epiphytic orchid 

 Eria ornata (Raciborski, 1898). 



Another species, Tillandsia tisneoides^ has a very different 

 habit : it hangs in long shaggy festoons from the branches 

 of trees. " This most remarkable of all epiphytes, often 

 completely covering the trees in tropical and subtropical 

 America, consists of shoots often far more than a metre in 

 length, thin as thread, and with narrow grass-like leaves, 

 and only in early youth fixed to the surface of the supporting 

 plant by weak roots that soon dry up. The plants of 

 Tillandsia owe their attachment to the fact that the basal 

 parts of their axes twine round the twigs of the host " 



Wffl^r 



Fig. 7. — Section through water-absorbing hair of Tillandsia iisneoides. 



X 280. (After Aso.) 



(Schimper). The whole plant is covered with shield hairs 

 similar to those described, but not sunk below the epiderm 

 (Fig. 7). When dry the plant is silvery, like the velamen- 

 covered root of an orchid. Goebel remarks that in South 

 America Tillandsia is often used as a balcony decoration ; 

 the shoots are simply tied on to the rails, where the flourish 

 of blossom is a sufficient proof that such root system as is 

 present can be dispensed with so far as water absorption 

 goes. 



It has been asserted by Mez (1904) that certain forms 

 of Tillandsias of the T. iisneoides type draw their supplies 

 less from rain than from dew. There seems no reason to 

 doubt that dew faUing on such a plant may be utilised. Aso 

 (19 10) has shown that the hairs of T. iisneoides are capable 

 of absorbing salts, while those of the related Ananas sativa, 

 the pine-apple, cannot do so. 



Volkens (1887) assigns an important role to dew in the 



