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. The pseudobulbs are enveloped by sheaths.
These are medium-sized to very large orchids, including the Giant Orchid (Grammatophyllum speciosum), believed to be the largest orchid species in existence. 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 roots form spectacular bundles.
The more modest Bell Orchid (Grammatophyllum scriptum) is another well-known species, with pseudobulbs of 20cm, 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. See also Dendrobium cuthbertsonii, whose flowers have been reported to last up to ten months each.
Grammatophyllum 'Tiger's paw' is a hybrid from G. elegans and G. fenzlianum.
- Gabertia Gaudich.
- Pattonia Wight
- Grammatophyllum elegans (Fiji and Philippines).
- Grammatophyllum fenzlianum (Maluku (Ambon).
- Grammatophyllum kinabaluense (N. Borneo).
- Grammatophyllum martae (Philippines )
- Grammatophyllum measuresianum (Philippines).
- Grammatophyllum multiflorum (Philippines).
- Grammatophyllum rumphianum (Borneo, Maluku).
- Grammatophyllum schmidtianum (Marianas).
- Grammatophyllum scriptum : Bell Orchid (Malaysia to SW. Pacific).
- Grammatophyllum scriptum var. boweri (Papuasia to Santa Cruz Is.)Hemicr. or cham.
- Grammatophyllum scriptum var. scriptum (Malaysia to SW. Pacific). Hemicr. or cham.
- grammatophyllum scriptum gitrinum 'hihimand'
- grammatophyllum scriptum... the 'deliver
- Grammatophyllum speciosum : Giant Orchid, Tiger Orchid, Queen of Orchids (Indo-China to Solomon Is.) - type species
- Grammatophyllum stapeliiflorum (Malaysia, Philippines to New Guinea).
- Grammatophyllum wallisii (Philippines )