Kaempferia subg. Protanthium

Nopporncharoenkul, Nattapon, Sukseansri, Wiphada, Nopun, Possathorn, Meewasana, Jiraporn, Jenjittikul, Thaya, Chuenboonngarm, Ngarmnij, Viboonjun, Unchera & Umpunjun, Puangpaka, 2024, Cytotaxonomy of Kaempferia subg. Protanthium (Zingiberaceae) supports a new limestone species endemic to Thailand, Willdenowia 54, pp. 121-149 : 140-141

Key to the taxa of Kaempferia subg. Protanthium of Thailand

(Revised from Nopporncharoenkul & Jenjittikul 2024 and Nopporncharoenkul & al. 2024)

1. Floral plane perpendicular to ground; lateral staminodes upright to slightly arcuate; labellum deflexed in distal half with an incision around or less than 1/2 of its length................................. 2

– Floral plane flat, parallel to ground; lateral staminodes and labellum horizontal to slightly arcuate, arranged in same plane; labellum with an incision around or more than 3/5 of its length.................. 10

2. Anther connective tissue and filament puberulent with very short glandular hairs dorsally and laterally ........................................ 3

– Anther connective tissue and filament glabrous... 6

3. Leaves adpressed to ground, suborbicular to ovate; ligule 1.5–3 cm long............ K. jenjittikuliae

– Leaves semi-adpressed to upright, ovate, elliptic, to lanceolate-oblong; ligule less than 1 cm long.... 4

4. Labellum with two conspicuous yellow bands from base toward centre; anther crest with obtuse to trilobed-undulate apex, middle lobe more elongated than side lobes.................. K. simaoensis

– Labellum with central white, cream white to pale yellow patch basally; anther crest with bifid to bilobed, sometimes with 1–3 small teeth between main lobes ........................................ 5

5. Labellum with central pale yellow patch basally; nocturnal anthesis....... K. noctiflora var. noctiflora

– Labellum with central white to cream white patch basally surrounded by two light purple stripes from base toward centre of lobes; diurnal anthesis........................... K. noctiflora var. thepthepae

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

– Leaves lanceolate-oblong, elliptic to ovate; more than 5 cm wide................................ 7

7. Labellum narrowly obovate with an incision c. 1/3 of its length; ligule opaque, 7–14 mm long; storage roots branched with numerous, lateral and terminal subglobose to ovoid tubers; tubers 0.5–1 by 0.5–0.8 cm ............................... K. subglobosa

– Labellum obdeltoid to broadly obovate with an incision c. 1/2 of its length; ligule translucent, 1–5 mm long; storage roots unbranched with a single, terminal fusiform, ellipsoid to ovoid tuber; tuber 1.2–3.5 by 1–2 cm .................................. 8

8. Anther crest with bifid to bilobed apex, usually with 1–3 small teeth between main lobes; epigynous glands 2–6 mm long................ K. rotunda

– Anther crest with tridentate to undulate-truncate apex; epigynous glands 6–12 mm long......... 9

9. Bracts and bracteole sparsely villous; epigynous gland 8–12 mm long................. K. aurora

– Bracts and bracteole glabrous; epigynous gland 6–7 mm long........................ K. sipraiana

10. Anther connective tissue and filament puberulent with very short glandular hairs dorsally and laterally....................................... 11

– Anther connective tissue and filament glabrous.. 12

11. Labellum with white to cream white patch basally toward centre................... K. lopburiensis

– Labellum with deep pink to deep purple patch basally toward centre................... K. udonensis

12. Pseudostem buried in ground; leaves adpressed to semi-adpressed to ground, orbicular, suborbicular to ovate......................... K. grandifolia

– Pseudostem upright and outstanding above ground; leaves lanceolate-oblong, elliptic to broadly ovate......................................... 13

13. Lateral staminodes white; labellum white with pale yellow patch basally toward centre........... 14

– Lateral staminodes white, light pink to deep pink; labellum white, light pink to purple with two deep reddish to deep purple spots at centre............ 15

14. Petiole subsessile to 2.5 cm long; nocturnal anthesis................................ K. albiflora

– Petiole more than 10 cm long; diurnal anthesis.................................. K. caespitosa

15. Anther crest oblong to ovate with bifid to bilobed apex, usually with 2–3 small teeth between lobes; labellum with an incision more than 2/3 of its length................................. K. takensis

– Anther crest obreniform, broadly ovate, obovate to obdeltoid with irregular undulate to crenate apex; labellum with an incision c. 3/5 of its length...................................... K. calcicola