Key to the species of Gigantochloa in China

1a. Branches several, without a dominant branch; leaf sheath outer ligule more than 2 mm tall.

2a. Culm sheath ligule less than 5 mm tall; auricle more than 2 mm tall.

3a. Culm sheath blade reflexed; auricle prismatic, up to 10 mm wide; ligule entire; leaf sheath ligule more than 2 mm tall.................. ......................................................................................................................................................................................... 1. G. callosa

3b. Culm sheath blade erect; auricle oblong, 6–7 mm wide; ligule dentate; leaf sheath ligule less than 2 mm tall.................................. ......................................................................................................................................................................................2. G. manensis

2b. Culm sheath ligule 10 mm tall; auricle linear, 10 mm wide, less than 1 mm tall ............................................... 3. G. brachystachya

1b. Branches with a dominant branch; leaf sheath outer ligule less than 1 mm tall.

4a. Abaxial culm sheath with stripes, ligule less than 10 mm tall.

5a. Culm sheath abaxially sparsely hispid with brown to black deciduous hairs, strigose; blade erect; auricle narrowly falcate; ligule 6–10 mm tall.................................................................................................................................................................. 4. G. glabrata

5b. Culm sheath abaxially densely dark brown hispid; blade reflexed; auricle oval; ligule ca. 4 mm tall .................... 5. G. nigrociliata

4b. Abaxial culm sheath without stripes, ligule more than 10 mm tall.

6a. Intranodes glabrous; culm sheath blade reflexed; auricle more than 10 mm wide ................................................... 6. G. albociliata

6b. Intranodes with hairs; culm sheath blade erect; auricle less than 10 mm wide.

7a. Branching from 8–10 th nodes above ground; infranodes glabrous; abaxial culm sheath with sparsely black strigose; blade lanceolate; leaf sheath densely brown strigose.......................................................................................................................................7. G. felix

7b. Branching from 13-15 th nodes above ground; infra nodes with a ring of wihte hairs; abaxial culm sheath with sparsely brown strigose; blade oval lanceolate; leaf sheath glabrous...................................................................................................8. G. parviflora