Habit and leaf form. Shrubs. ‘Normal’ plants. Leaves well developed. Plants with roots; non-succulent; spiny (‘branchlets’); autotrophic. To 2 m high. Self supporting. Not heterophyllous. Leaves small; alternate; with blades; petiolate; with ‘normal’ orientation; simple; not peltate. Leaf blades entire; linear, or obovate, or elliptic; pinnately veined. Mature leaf blades adaxially glabrous (or with antrorse or patent hairs); abaxially glabrous (or with antrorse or patent hairs). Leaves with stipules. Stipules scaly, or leafy; persistent. Leaf blade margins entire, or dentate; revolute (‘recurved’). Leaf anatomy. Hairs present, or absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescences simple; axillary. Flowers long pedicellate; bracteate; minute; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; widely spreading; valvate; regular; white, or pink. Calyx lobes ovate. Epicalyx absent. Corolla present; 5; 1 -whorled; alternating with the calyx; polypetalous; regular; white, or pink. Petals clawed; hooded. Androecium present. Fertile stamens present. Androecial members definite in number. Androecium 5. Androecial members adnate (to the base of the sepals); free of the gynoecium; free of one another; 1 -whorled. Stamens 5; all more or less similar in shape; isomerous with the perianth; alternisepalous; filantherous. Anthers separate from one another; dehiscing via longitudinal slits; bilocular; tetrasporangiate; appendaged. The anther appendages basal. Fertile gynoecium present. Gynoecium 3 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious; inferior. Ovary plurilocular; 3 locular. Gynoecium stylate. Styles 1; apical. Stigmas 3 - lobed. Ovules 1 per locule (in WA); ascending; anatropous.
Fruit and seed features. Fruit aerial; 7–8 mm long; a schizocarp. Dispersal unit the seed, or the fruit. Seeds 1 per locule.
Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia. South-West Botanical Province. A genus of 1 species; 1 species in Western Australia; G. intangendus (F.Muell. ex F.Muell.) Rye; 1 endemic to Western Australia.
Etymology. From the modern word granite combined with the Greek for "in the nature of; in mineral terms", in reference to the granite habitat to which the taxon is restricted.