TWO PINNATE LEAF BOKONIAS AND THEIR ESSEN'JIAL OILS. 209 



EXPLANATION OF PLATES. 



Plate XII. 

 Boronia tkujona, sp. nov. 



Plate XIII. 



Figs. 1 and 2. Individual flowers. 

 ,, 3. Stamens (enlarged). 

 ,, 4. Individual stamen (enlarged). 

 ,, 5. Ovary, style and stigma (enlarged). 

 ,, 6. Leaf showing minute serrulations. 



Plate XIV. 



Fig. 1. Transverse section of the leaf of Boronia pinnata. Two 

 oil glands in section are directed towards the upper sur- 

 face, the one on the right with two cover cells sunk 

 below the normal epidermis on either side. The epi- 

 dermal layers are comparatively evenly developed, and 

 stomata are found on either surface. The palisade 

 tissues are distinctly seen towards the upper surface, 

 x 27. 



Fig. 2. The transverse section of the leaf of Boronia thujona, 

 showing the thin texture with a very loose palisade and 

 spongy mesophyll. Stomata are usually found on the 

 lower surface only. The cells of the upper epidermis 

 are much larger, and more heavily cutinised than those 

 of the lower surface. A single oil gland is seen on the 

 left. x 27. 



Fig. 3. Horizontal section, slightly oblique, of the leaf of Boronia 

 thujona. On the left the palisade mesophyll is cut trans- 

 versely, gradually passing on the right into the spongy 

 tissue, with increasingly large intercellular spaces. Four 

 oil glands are shown in section. x 70. 



Fig. 4. Transverse section of the flower bud of Boronia thujona. 

 Peripherally are the four sepals in section, several 

 possessing distinct oil glands. Within these are the four 

 imbricate petals, those towards the top and left of the 

 plate with a single oil gland The section passes through 

 the eight perfect stamens and their connectives, though 

 the filaments are alternately long and short. The pollen 

 grains are distinctly seen. Within the anthers the upper 

 portion of the ovary is shown in section with its four 

 lobes, in two of which are the ovules. x 30. 



N— November 2, 1921. 



