Bbtts. — Autecolorjy of Plants of Peridotite Belt, Nelson. 295 



Between the Isundle-sheatli and the lower epidermis there are some 

 thin-walled colourless cells which store water. 



Stem. — The epidermis consists of squarish cells with their walls slightly 

 thickened and with a thin cuticle. These cells contain tannin. Some of 

 the epidermal cells are produced into hairs like those on the leaf. 



The cortex consists of small regular cells ; in the outer part of the 

 cortex these cells have their walls lignified and also suberized. The inner 

 layers of cortical tissue consist of thin-walled cells. All the cortical cells 

 are closely packed together, so that there are only very small intercellular 

 air-spaces. There is a well-marked endodermis, which consists of large 

 cells with suberized walls. 



The phloem forms a wide, continuous band ; it contains a large amoimt 

 of parenchyma. 



The xylem forms a band about the same width as the phloem ; it con- 

 sists of vessels of rather small diameter and of wood-fibres. 



The pith is solid, and consists of large, thin-walled polygonal cells which 

 are closely arranged together. The pith-cells adjacent to the xylem are 

 somewhat smaller and have their walls lignified. 



33. Cassinia Vauvilliersii Hook. f. var. rubra Buch. 



Habit. — This plant is an erect, closely branching shrub,. 2-4 ft. high ; 

 the branches are stout, erect, and often glutinous. The leaves are nume- 

 rous, close-set, erect or spreading, J-^ in. long, linear-obovate, narrowed 

 into a short broad petiole, very coriaceous, clothed with hairs on both 

 surfaces ; the margins are slightly recurved. 



Anatomy. 



Leaf. — The upper epidermis consists of rather small cells which have 

 slightly thickened walls. These cells contain a few small chloroplasts. 

 There is a thick cuticle. Some of the epidermal cells are produced into 

 long 3- or 4-celled hairs — ^2 or 3 small hairs at the base and a long cell at 

 the end. There are no stoma ta on the upper surface. 



The lower epidermal cells are smaller than the upper, and, like the 

 latter, contain chloroplasts. Many of the cells are produced into hairs 

 like those on the upper surface. The lower epidermal cells have slightly 

 thickened walls, and there is also a thick cuticle. 



The chlorenchyma is differentiated. The palisade tissue consists of 4 

 rows of large cells with slightly thickened walls and large chloroplasts. 

 There are very small air-spaces between the cells. 



The spongy parenchyma is composed of rather small, irregular cells 

 which contain large chloroplasts. The walls are slightly thickened, and 

 there are fairly large air-spaces between the cells. 



Stomata are confined to the lower surface ; they are of the same type 

 as in Celmisia longifolia var. gracilenta. 



The vascular bundles are small, and contain only a small amount of 

 lignified tissue. They are surroujided by a sheath of thin- walled paren- 

 chymatous cells which contain only a small number of chloroplasts. 



Stem. — The epidermis is composed of small cells which have thickened 

 walls and also a fairly thick cuticle. Many of the cells are produced into 

 hairs like those on the leaf. 



Then there come some dead cortical cells ; these have thick brown 

 walls. Inside this layer there is suberized tissue, from 1 to 4 cells deep. 

 The cells are large, thin-walled, and irregular. 



