The bulbs are tunicated and offset by production of daughter bulbs and/or bulbils from rhizomes, which appear root-like. The petiolate leaves range in form from elliptic to ovate, and are slightly falcate in subg. Hyline. The lamina, which has a distinct midrib, has pronounced parallel venation intersected by transverse striae, and may be variously speckled whitish in some species. The scape is solid, ancipitous (two-edged), and tumbling. The two spathe bracts are obvolute (i.e. partially fused at the base and overlapping), persistent and enclose a 2-20 flowered umbel of lilac and/or white zygomorphic flowers; the outer whorl of tepals are apiculate. The genus is unique in the Amaryllidaceae for the presence of a true hypanthium, formed by the continuation of the perigonal tube over the ovary in some of the species. The positioning of the perigone is either epiperigynous (i.e. the floral tube surrounds the inferior ovary and forms a true hypanthium) or epigynous (i.e. the floral tube is inserted at the top of the ovary). The filiform style is declinate and the stigma is capitate. The stamens are arranged in either a 5 + 1 manner (Griffinia subg. Griffinia) or all 6 fascicled and declinate (Griffinia subg. Hyline). The fruit is an angular, ovoid, trilocucidal, dehiscent capsule, typically with one seed. The seed lacks phytomelan, has a whitish testa, is turgid and (sub-) globose. The chromosome number for the genus is 2n = 20 (Figure 3), although 2n = 30 occurs in some individuals.

The morphology of the two subgenera is divergent, primarily in the flowers. In Griffinia subg. Griffinia, the leaves are symmetrical and vary from narrowly elliptic to broadly ovate, the lamina may be speckled whitish in some species (e.g. G. liboniana and G. espiritensis). The inflorescence is 4–20-flowered. The flowers are variable in size, ranging from 1.5 cm. to about 11 cm long, diurnal, unscented, and lilac and/or white. The perigonal tube is reduced in the small, blue-flowered species. The tepals are arranged in a 5 + 1 pattern, giving a bilabiate appearance. In the small epigynous species, the lowermost tepal is narrow, revolute and divaricate. Five stamens are declinate, two ranked (two long and three short), and, the sixth (when present) is assurgent; the pollen is white. The number of ovules per locule ranges from 2-8 (-10). The chromosome number is 2n = 20 for most species, however, for some forms of G. liboniana and G. espiritensis the chromosome number is 2n = 30.

In Griffinia subg. Hyline the leaves are slightly falcate and narrowly elliptic to lorate. The inflorescence is 2–3-flowered, and the flowers are large, nocturnal, scented and white with green in the throat. The perigone is epiperigynous and is fused into a tube, albeit highly variable in length. The perianth is not as strongly zygomorphic as in subgenus Griffinia. All six stamens are fascicled, in three ranks of two, and declinate; the pollen is yellow. The number of ovules per locule ranges from 10-16.