1	Thick fleshy leaves and margin significantly serrate, epichile reniform and margin with dentation, and hypochile subconic	G. prionophyllus
–	Fleshy leaves and margin without serrate, epichile suborbicular or rhomboid and margin without dentation, and hypochile cupular	2
2	Epichile with thickened cushion on the center	3
–	Epichile without cushion on the center	4
3	Subumbellate inflorescence, orbicular cushion on the central epichile	G. distichus
–	Corymb inflorescence, diamond cushion on the central epichile	G. corymbosus
4	Hypochile narrower than epichile	5
–	Hypochile broader than epichile	6
5	Epichile with two ridges ranging from base to apex	G. affinis
–	Epichile membranous with longitudinal ridges centrally	G. alatus
6	Inflorescence 1 or 2-flowered; leaves without awns at apex	G. fuscopunctatus
–	Inflorescence 5 or 6-flowered; leaves with 1–3 short awns at apex	7
7	Epichile cordiform and without papillate	G. kadooriei
–	Epichile subobucular and with palillate	G. pseudodistichus