CLASSIFICATION OF GROWTH-FORMS. 19 
(e.) The Tussock Form.—This is so well known that it requires 
no description. It occurs chiefly amongst the grasses and sedges, 
though probably the New Zealand flax (species of Phormiwm) should 
come here. Some species build fairly tall, solid trunks out of their 
dead stems and other parts. Examples: the silver-tussock (Poa 
caespitosa), the red-tussock (Danthonia Raoulit var. rubra), and the 
trunk-building niggerhead (Carex secta). About 40 species, belonging 
to 19 genera and 5 families, possess this form. 
(f.) The Cushion Form.—Dense crowding of short branches spread- 
ing out from a centre and leaves inserted extremely closely on the 
stems lead to the building of more or less dense cushions. Examples : 
the vegetable-sheep (species of Haastia and Raoulia) (fig. 64), the 
common scleranth (Scleranthus biflorus), and the silvery celmisia 
(Celmisia argentea). About 55 species, belonging to 22 genera and 
14 families, are cushion-plants or semi-cushion plants. 
(g.) The Rosette Form.—The leaves, crowded at the ends of the 
branches, form rosettes of various shapes and sizes, some being 
flattened close to the ground. Examples: various plantains (species 
of Plantago) and the common New Zealand groundsel (Senecio 
bellidicides). The rosette form is frequently associated with some 
other growth-form. 
(h.) The Tree-fern Form.—There is a fairly high trunk covered 
more or less with aerial roots, and a crown of huge, spreading 
leaves. Examples: the slender tree-fern (Dicksonia squarrosa) and 
the black tree-fern (Cyathea medullaris). 
(7.) The Liane Form.—This includes all the climbing-plants, of 
which the following classes may be distinguished: (1) Scramblers ; 
(2) twining climbers; (3) tendril- climbers; (4) root - climbers. 
Examples: the supplejack (Rhipogonum scandens), twiner (fig. 9) ; 
the scarlet climbing-rata (Metrosideros florida), root-climber. There 
are 47 climbing-plants, belonging to 16 families and 22 genera: 
12 are scramblers, 13 root-climbers, 13 twiners, and 9 tendril-climbers. 
Of this total, 33 are woody and 14 herbaceous. Lianes are dealt 
with at some length in Chapter IV. 
(j.) The Mistletoe Form.—tThis is the form of the semi-parasites, 
which take part of their nutriment from the trees, shrubs, lianes, 
or even other parasites to which they are attached, and part is 
manufactured in their green leaves from carbonic acid and water. 
All are shrubs. Examples: the red mistletoe (2lytranthe tetrapetala), 
