Kaempferia subg. Protanthium, Nopporncharoenkul, 2020

Nopporncharoenkul, Nattapon, Somnoo, Thunchanok, Tanming, Wattana & Maknoi, Charun, 2021, KAEMPFERIA JENJITTIKULIAE (KAEMPFERIA SUBG. PROTANTHIUM: ZINGIBERACEAE), A NEW, ENDANGERED SPECIES ENDEMIC TO THAILAND, Edinburgh Journal of Botany 78 (350), pp. 1-13 : 10-11

Key to the species of Kaempferia subg. Protanthium

1a. Nyctanthous ______________________________________________________________________ 2

1b. Hemeranthous ____________________________________________________________________ 4

2a. Leaves obovate to suborbicular; ligule bilobed, c. 1 cm long _____________ K. grandifolia

2b. Leaves ovate, elliptic to lanceolate; ligule bilobed-truncate, 1–3 mm long ___________ 3

3a. Leaves ovate to broadly elliptic, green to deep purplish red, usually with a deep purplish red patch towards the midvein; lateral staminodes upright to slightly arcuate; labellum deflexed distal half with incision around half of its length; labellum base flat K. noctiflora

3b. Leaves elliptic, lanceolate-oblong to narrowly lanceolate, green; lateral staminodes and labellum horizontal, arranged in the same plane; labellum with incision up to two-thirds of its length; labellum base involute, enclosing the anther __________________ K. albiflora

4a. Floral plane perpendicular to the ground; staminodes upright to slightly arcuate; labellum deflexed distal half with incision around half of its length __________________ 5

4b. Floral plane parallel to the ground; lateral staminodes and labellum horizontal, arranged in the same plane; labellum with incision more than two-thirds of its length ________ 10

5a. Leaves adpressed to the ground, broadly ovate to suborbicular ________ K. jenjittikuliae

5b. Leaves upright; linear, narrowly lanceolate, lanceolate-oblong, elliptic to ovate _______ 6

6a. Leaves linear grass-like to narrowly lanceolate-oblong, less than 5 cm wide K. graminifolia

6b. Leaves lanceolate-oblong, elliptic to ovate, more than 5 cm wide ____________________ 7

7a. Labellum with two conspicuous yellow bands from base towards sinus; anther crest obtuse to trilobed-undulate, the middle lobe more elongated than side lobes K. simaoensis

7b. Labellum with a white or pale yellow band from base towards sinus, usually surrounded by purple stripes; anther crest bilobed to tridentate _____________________ 8

8a. Anther crest tridentate; epigynous gland 8–12 mm long; colour of wilted staminodes and labellum brownish orange _____________________________________________ K. aurora

8b. Anther crest bilobed, usually with 1–3 small teeth or lobes between the main lobes; epigynous gland 2–6 mm long; colour of wilted staminodes and labellum white with deep purple to blue ________________________________________________________________ 9

9a. Leaves petiolate; ligule less than 5 mm long ______________________________ K. rotunda

9b. Leaves sessile; ligule 6–9 mm long __________________________________ K. kamolwaniae

10a. Leaves upright, oblong, elliptic to ovate ___________________________________________ 11

10b. Leaves adpressed to the ground, broadly ovate, suborbicular to orbicular ___________ 13

11a. Lateral staminodes pure white; labellum white with a pale yellow patch from base towards sinus _________________________________________________________ K. caespitosa

11b. Lateral staminodes light pink to purple; labellum light pink to purple with two large darker pink to deep purple spots at sinus _________________________________________ 12

12a. Leaves sessile, green __________________________________________ K. xiengkhouangensis

12b. Leaves petiolate, green usually with 1–3 layers of white to pale light green variegation K. takensis

13a. Labellum with a white patch from base towards sinus _________________ K. lopburiensis

13b. Labellum without a white patch from base towards sinus ________________ K. udonensis