162 Transactions. 



Rhizome long, creeping, giving rise at intervals to new plants. 



Leaves sheathing at the base, sheaths completely surrounding the stem : 

 about | in. broad, grooved, glaucous-green, coriaceous, upper surface con- 

 cave, leaf bending over towards the ground and tapering to a point, midrib 

 prominent in adult leaf. 



(c. ) Leaf-anatomy. 



Epidermis : On concave surface epidermis consists of large bulliform 

 cells ; in the seedling the cells in the middle of this surface extend fully a 

 quarter of the way into the leaf. Convex surface — oblong cells with thick 

 cell-walls, those parallel to the leaf -axis being undulate ; stomata frequent, 

 parallel to leaf-axis ; level with surface ; cuticle present. 



Chlorencyhma : In the seedling, slightly differentiated, with palisade cells 

 towards the outside and polygonal cells in the interior ; water-storage tissue 

 in the chlorenchyma cells, beginning to appear between mestome bundles. 

 In the adult there are two or three layers of palisade cells on the surface, 

 about two on the concave surface ; inner cells irregular, polygonal, with 

 intercellular spaces. Large water-storage tracts alternate with the bundles, 

 sometimes there being only one layer of chlorenchyma around the paren- 

 chyma sheath. 



Stereome occurs adjacent to the vascular bundles or subepidermal in 

 origin. 



Fibro-vascular bundles in a single row through the leaf, surrounded by a 

 mestome sheath and a parenchymatous sheath, some cells containing chloro- 

 plasts, others quite colourless. 



(d.) Conclusion. 



Carex pumila, as far as anatomy goes, is xero phytic ; for instance, 

 cuticle, chlorenchyma differentiated with palisade tissue on both sides of 

 leaf, well-developed water-storage tissue, large epidermal cells on the con- 

 cave surface which can contract when dry and thus enable the leaf to 

 protect itself against transpiration by arching. The tufted growth-form is 

 also xerophytic. All this is contrary to what might be expected from the 

 fact that the plant grows in moist hollows. 



8. Leptocarpus simplex. , , „ , . 



* (a.) Habitat. 



Found commonly in moist hollows, sand-plains, and marshy places. At 

 the south end of the beach it grows chiefly on the sand-plain among the 

 manuka (Leptospermum. scoparium), and in the north portion it is common 

 in wet places and in pools. Besides growing in dune areas, it is the most 

 characteristic plant of salt swamp ; but it also occurs under mesophytic 

 conditions inland, as on the gravel shores of Lakes Te Anau and Manapouri. 



(b.) Growth-form. 



A rush-like plant which forms dense tussocks of a dull-green or brownish- 

 yellow colour, to which a characteristic mottled appearance is given by the 

 numerous small blackish scales clasping the stem at intervals of about 3 in. 



Rhizome stout, woody, creeping, covered with brown scales. 



Stems erect, stiff, wiry, terete, rush-like, slender, diameter less than 

 ^ in ; 1-3 ft. long. 



Leaves reduced to scales. 



