Ironside. — Anatomical Structure of N .Z. Piperaceae. 



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the reduction may be found in the epiphytic habit of many of the forms " ; 

 and later says, " Nothing has been said regarding the bearing of the 

 geophilus habit exhibited by certain species of Peperomia." 



Macropiper excelsum comes very near a geophilous condition in having 

 a swollen base stored with food-material ; the adventitious roots near the 

 base and for some distance from it are also stored with starch. The plant 

 is sometimes tall, sometimes short and more shrub-like. Peperomia 

 Endlicheri occurs both as a lithophyte and chasmophyte, less often as an 

 epiphyte. Under these conditions it has succulent stems and adventitious 



Qp cp 



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Six steles passing downwards through lowermost internode of seedling (diagrammatic) : 

 a, four bundles just formed again in centre; b, c, central bundles joining to form 

 two; c, d, e, central bundles move further and further outwards till they are finally 

 merged in outer ring ; e, slightly elongated, passing out to root; /, stele with branch 

 to root. All the steles are slightly eccentric with regard to rest of stem. 



roots, both stem and root showing reduced structure. Now, very many 

 Monocotyledons are adapted to suit geophilous, epiphytic, aquatic, or 

 saprophytic conditions. 



Stem-structure. 



It has been shown (Miss Sargant) that in connection with a geophilous 

 condition extra - fascicular cambium would first disappear; then the 

 cambial zone, because the need for mechanical vascular tissue has dis- 

 appeared. M. Queva has shown that a distinct cambial zone occurs with 

 the bundles of some Monocotyledons, and traces of it in others. Now, 

 in Macropiper excelsum, while there is no interfascicular bundle-formation, 

 there is marked secondary thickening, necessary to its form. In some 

 Peperomias the bundles are arranged in rings, as P. galioides. In Pepe- 

 romia Endlicheri the scattered vascular system, and the fact that, though 



