Hekkiott. — Plants from the Southern Islands. 417 



Carex trifida, Cav. 



A very large tall robust leafy sedge, 3 ft. to 6 ft. high ; culms 

 stout, obtusely 3-9-ouous, leafy, smooth. Leaves very large and 

 long, \ in. broad or more, flat, keeled, striate ; margins sca- 

 brid. Is much the largest New Zealand species.* 



Hah. — This plant is common in New Zealand and in all 

 the Southern Islands except Macquarie and Bounty Islands. 

 In the islands it is a common constituent of swampy ground, 

 taking the place of the tussock-grass. It grows in immense 

 tussocks. The leaf is conduplicate, with a prominent keel on 

 the outer surface. 



Anatomy (fig. 28). — The upper epidermis (ep.) is composed 

 of large cells with cuticularized outer walls, slightly convex. 

 The cells of the lower epidermis (l.ep.) are small, but still thick- 

 walled, and interrupted by numerous stomata (st.). Masses of 

 stereom tissue (sm.) occur above the smaller vascular bundles, 

 and below the main one situated in the keel of the leaf. Above 

 this main bundle is a mass of large-celled parenchyma, a single 

 layer of which extends below on either side the upper epi- 

 dermis to the first vascular bundle. The chlorenchyma (chlor.) 

 is not differentiated, but consists of a mass of small rounded 

 cells arranged in two layers adjoining each epidermis, leaving 

 between large air-cavities which are separated by strands of 

 tissue surrounding the vascular bundles. Each bundle (v.b.) 

 is surrounded by a more or less well-defined endodermis (endo.). 

 It occurs near the lower surface of the leaf, and the space 

 between it and the upper epidermis is filled up with a mass 

 of round thick-walled stereom tissue. 



Poa foliosa, Hook. f. Festuca foliosa, Fl. N.Z., i, 308. 



" Culms stout, tufted, tall or short, 1 ft. to 3 ft. high. 

 Leaves flat, glabrous, coriaceous, shorter or longer than culms, 

 T V in. to J in. broad ; ligule short, membranous, sheaths com- 

 pressed." 



Hab. — This is found on all the islands, excepting of course 

 the Bounty Islands, on which no vegetation occurs except a 

 species of Durvilla?a attached to the rocks, and on the rocks 

 a species of alga. It forms broad zones of tussock in the dif- 

 ferent formations, and frequently attains a considerable size. 



Anatomy (figs. 29a, 29&, 29c). — The leaf is hinged, and folds 

 over on the central ridge at a, a. The ordinary upper epidermal 

 cells (ep.) are rectangular, with the long axis vertical to the 

 surface, and the outer wall projects into small papillae with 

 thickened outer walls (cf. Accena). (See fig. 296.) The epider- 



* Hooker (1867), p. 316. 

 14— Trans. 



