236 



Transactions. 



5. Claytonia australasica Hook. f. 



Usual Growth-form. — " A perfectly glabrous tender and succulent usually 

 matted plant, with slender creeping stems 1-6 in. long. Leaves very vari- 

 able in size, J-H in. long, alternate or in distant pairs, narrow-linear or 

 linear-spathulate, obtuse, dilated into broad membranous sheaths at the 

 base." 



Mineral Belt Growth-form. — In the Mineral Belt plants the leaves are 

 i-i in. long. 



Anatomy. 



Leaf (figs. 5 and 6). — The upper and the lower epidermis are similar ; 

 the epidermal cells are large and have thickened walls. A very thin 

 cuticle is present. Stomates are confined to the upper surface of the leaf. 



Fig. 5. — Claytonia australasica. Diagrammatic view of leaf ( x 40). a, palisade 



tissue ; b, aqueous tissue. 

 Fig. 6. — Claytonia australasica. Transverse section of leaf, passing through 



midrib (X lfiO). a, guard-cell ridge; b, palisade tissue; c, xylem; 



d, phloem ; e, aqueous tissue. 



The guard-cells are at the same level as the other epidermal cells, and the 

 opening is protected by guard-cell ridges. The cells of the epidermis contain 

 a few small chloroplasts. 



