What is the meaning of Grass_tree?

Any of various small trees of the family Xanthorrhoeaceae (especially of the genus Xanthorrhoea), having a thick trunk crowned with a dense tuft of pendulous, grass-like leaves.

A New Zealand shrub of the genus Dracophyllum, that grows up to 12 m high and found throughout in drier climates and at higher altitudes, with slender erect or spreading branches. Rigid, leathery grass-like leaves are usually crowded towards the tip of the branchlets. Also called spiderwood.

Dasylirion longissimum (family Asparagaceae, Mexican grass tree)

Dracophyllum (family Ericaceae), a genus of about 100 species.

Richea pandanifolia (family Ericaceae, giant grass tree).

Source: wiktionary.org