Chapter I 



13 



Heliamphora 



much shorter in the only leaf I could examine, while in H. Tyler i (of 

 which I examined two leaves) there is but a shght commissure above 

 the drain slit, or it may be quite open, as it is in H. nutans. The 

 length of the slit is about i cm. more or less, and has cihated margins, 

 since it lies within the hairy zone of the bell near its lower limit. 

 Owing to the fact that the specimens were dried and pressed "types", 

 I was limited in my examination. Where the slit of the bell in H. 

 Macdonaldae seemed to be open, this may have been due to the sepa- 

 ration of the fused margins in drying (Lloyd 1933). 



Fig. I. — I, Heliamphora Tatei; 2, H. Macdonaldae; 3, H. minor, the zonation of the 

 interior surface is indicated by the numbers 1-4; 4, H. minor; 5, H. nutans; 6, retrorse 

 hair of H. minor; 7, twin hairs of H. minor. 



It is quite evident that the presence of the drain slit discovered 

 by Tate would render tall plants, which grow to the height of four 

 feet and inhabit a very rainy habitat, far less top-heavy. The up- 

 right position of the leaves is further assured by the ample, tightly 

 clasping, stipular wings. At the same time it is to be observed that 

 the adaptation is not equally expressed in all three species, being least 

 so in H. Tyleri, in which the slit may not be present at all, the bell 

 being slit all the way down to the limit of the hairy zone. So far as 

 the effect is concerned, this amounts to the same thing, since the 

 water is drained off to the lowest open point of the bell in any case. 



Trichomes. — There are two kinds of hairs to be found on the inner 

 surface of the pitcher, those of the bell and adjacent tube, that is of 

 the conducting surface of Hooker, and those of the basal portion of 

 the tube. They are of identical morphology, but differ in important 



