Grammatophyllum, sometimes abbreviated in horticultural trade as Gram, is a genus of 13 currently known orchid species.

[3] This epiphytic genus occurs in dense rainforest from Indo-China, to Indonesia, Malaysia, the Philippines, New Guinea, and the Southwest Pacific islands.

[1] The species produce several racemes, arising from the base of the pseudobulb, with many yellow-green to olive-green, waxy flowers with dark purplish-red marks.

Its pseudobulbs can grow to a length of 2.5 m. Plants can develop into gigantic clusters weighing from several hundred kilograms to one ton.

The more modest bell orchid (Grammatophyllum scriptum) is another well-known species, with pseudobulbs of 20 cm, from which originate 3 to 4 stout leaves with a length of 1 m. Grammatophyllum multiflorum is one of the longest-blooming orchids in existence: it can be in bloom for nine months.