Kaempferia subglobosa Noppornch. & Jenjitt., 2024

Kaempferia subglobosa Noppornch. & Jenjitt. , sp. nov. (subg. Protanthium ) — Fig. 1 View Fig , 2 View Fig , 3 View Fig

Etymology. The specific epithet ‘ subglobosa ’ refers to the unique characteristic of the species, the branched storage roots with numerous, tiny subglobose tubers absent in all known taxa belonging to Kaempferia subg. Protanthium .

Similar to Kaempferia rotunda L. in overall habit, inflorescences and flower colour, but differs in having the branched storage roots with numerous, tiny, lateral and terminal subglobose to ovoid tubers (vs storage roots not branched, consisting of a single, large, terminal fusiform, ellipsoid to ovoid tuber), ligules 7–14 mm long, opaque (vs ligules 1–3(–5) mm long, trans- lucent), labellum narrowly obovate with an incision around 1/3 of its length (vs labellum obdeltoid to broadly obovate with an incision around 1/2 of its length), and the anther crest bifid apex with apices aristate, incision ser- rate to undulate, incision base angular (vs anther crest bilobed apex with apices acute, incision entire, usually with 2–3 small teeth between incision base). — Type: Nattapon Nopporncharoenkul NNSB -749 (holo QBG! with sheet code 20192834 A3 - H, and spirit collection code 20192834 A3 - A; iso BK!, BKF!, SLR!including flowers preserved in spirit as part of a single speci- men), Thailand, Tak Province, Ban Tak District, Thung Kracho , alt. 510 m, 11 Sept. 2019. Paratypes are mentioned below .

Rhizomatous perennial herb, 40–62.6 cm tall. Rhizome conical to ovoid, 2 –2.5 by 1–1.5 cm, with fascicled storage roots, (6–) 14–20 cm long, and numerous lateral and terminal tubers. Root tubers subglobose to ovoid, 0.5–1 by 0.5–0.8 cm. Leafy shoot with 5–7 leaves. Pseudostem upright, up to 27.5 cm long, composed of leaf sheaths, more obvious when young as the leaf sheaths disengage with age. Bladeless sheaths 2–3, 4.5–8.5 cm long, reddish to deep purplish red, with shortly mucronate (c. 1 mm long) to acute apex, sparsely villous. Blade bearing sheaths green, reddish to deep purplish red, sparsely villous; ligule bilobed, lobes narrowly deltoid with acute apex, 0.7–1.4 cm long, opaque, reddish to purplish red, sparsely villous; petiole 5–10.5 cm by 3–5 mm, 4–6 mm thick, canaliculate, light green with deep purplish red basally, densely villous; lamina narrowly ovate to elliptic-oblong, 16–35.5 by 9–12.5 cm, adaxially light green, usually with 1–3 layers of deep green patches arranged parallel along the leaf edges, between the midrib and both sides of the edges, sometimes with silver tinged areas between deep green patches, glabrous, abaxially light green, usually purplish red tinged under the posi- tion of the adaxially deep green patches, densely villous, base slightly oblique, obtuse to rounded, margin entire to slightly undulate with purplish red band, apex acuminate to acute. Inflorescence lateral, emerging from the rhizome before the leafy shoot, partly embedded in the soil; peduncle obscured by bladeless sheaths, up to 1.2 cm long, puberulent; raceme fusiform-ovoid, 3.5–4.2 by 0.7–1.5 cm, composed of up to 15 bracts each supporting a single flower; bracts deltoid-ovate to narrowly ovate to ovate, 1.2–4.2 by 0.6–2 cm (outer bracts larger), apex slightly mucronate (c. 1 mm long), light green to cream-white with reddish to deep brownish red veins from apex, sparsely villous; bracteoles deltoid-ovate, c. 10 by 0.5 mm, hyaline, sparsely villous, apex deeply bifid, apices slightly mu- cronate and densely villous. Flowers 10–13 cm long, diurnal anthesis; floral plane perpendicular to soil, with lateral stami- nodes upright to slightly arcuate and deflexed distal half of the labellum. Calyx 4–5 by 0.4–0.5 cm, with unilateral incision 1–1.2 cm long from apex, apex trilobed-crenate with 3 cuspidate-teeth, semi-translucent white to cream-white, glabrous, sometimes sparsely villous at apex. Floral tube 5.2–7.5 cm by 1.5–3 mm, narrowly cylindrical at base above ovary, narrowly funnel-shaped distally, white, glabrous; dorsal corolla lobe narrowly ovate to oblong, 3–4(–4.7) by 0.4–0.6(–0.8) cm, apex hooded, mucronate, mucro 3–5 mm long, concave, white, glabrous; lateral corolla lobes narrowly ovate to oblong, 2.8–4(–4.6) by 0.3–0.5(–0.6) cm, apex mucronate, mucro 1–1.5 mm long, concave, white, glabrous; lateral staminodes narrowly obovate, elliptic to oblong, 2.8–4.5 by 1–1.7(–2) cm, apex obcordate, mucronate to acute, white; labellum narrowly obovate, 3.2–4(–5) by 1.6–2.5(–3.4) cm, shallowly bilobed with an incision around 1/3 of labellum length, base flat, lobes suborbicular to obovate, 1.3–1.8 by 1–2 cm, apex obcordate to slightly crenate, lobes partly overlapping, white to pale light purple with central white to pale yellow patch basally surrounded by two light purple stripes from base towards centre of lobes. Stamen 1.7–2(–2.4) cm long; filament 2–3 mm long, c. 1.5 mm broad, white, glabrous; anther 14–17(–22) mm long including straightened anther crest, connective tissue white, glabrous; anther thecae (5–)6–7 by 1–1.5 mm, white to cream white, dehiscing along their entire length; pollen white; anther crest oblong to narrowly ovate, 8–12(–17) by 4–4.5(–5) mm, apex bifid with apices aristate, incision 3–6(–12) mm deep, serrate to undulate, incision base angular (rarely with an interval). Pistil 6.5–8.6 cm long; ovary cylindrical, 3–5 by 1.5–2.5 mm, trilocular, white to pale yellowish cream, densely villous, ovules numerous, placentation axile; epigynous glands 2, subulate, 3.5–5 mm long, cream to cream white; style 6–8.2 cm long; stigma crateriform, 1.5–1.8 by 0.8–1 mm, ostiole ciliate. Fruit narrowly obovoid to ellipsoid, 1.5–1.7 cm by 6–6.5 mm, cream with several longitudinal stripes of brown spots from apex and reddish spots, densely villous at apex, with 9–12 seeds. Seeds ellipsoid to obovoid, 3.5–4.2 by 2– 2.4 mm, yellowish cream to light brown with reddish spots, with basally attached a fleshy, semi-translucent white, laciniate aril.

Distribution — This species is strictly endemic to Ban Tak District, Tak Province, northern Thailand.

Habitat & Ecology — Growing in loamy soil with high amount of organic matter, mostly in a shaded mixed deciduous forest on hills, usually near a stream, at 480–700 m elevation. During field work, we observed a red dwarf honeybee ( Apis florea Fabricius, 1787 ) visiting and entering the flower, and making contact with the anther. We, therefore, presume that this bee might be a pollinator of K. subglobosa .

Phenology — Flowering period starts in late-April and lasts until May. Fruit and seeds mature in May. Leafy shoots usually emerge in May. The plants enter dormancy in November.

Conservation status — The species is only known from Ban Tak District, Tak Province, northern Thailand. During our observations, populations in the type locality and adjacent area, which is less than 3 km from the type locality, consist of around a thou- sand mature individuals. However , the area with the existing population is not under any legal protection. Also , cultivation is in close proximity as land is used as cassava and corn plantations and as garbage dump area by local people. It is likely to be directly threatened by expansion of agriculture that will deteriorate the population. However , the Extent of Occurrence (EOO) and Area of Occupancy (AOO) remain at this point un- known. Due to the current information on population size and threatening factors, we propose to assess K. subglobosa as Vulnerable ( VU C2 a(i) and D1), in accordance with the IUCN Red List Categories and Criteria, version 15.1 ( IUCN Standards and Petitions Subcommittee 2022) .

Vernacular name — We propose the common name ดอกดิน ไข่ปลา (Dok Din Khai Pla) in Thai language. Dok Din is the flower which occurs on the ground and Khai Pla means fish eggs. The name refers to the number and shape of tubers, which resemble fish eggs.

Other specimens examined (paratypes). THAILAND, Tak Province, Ban Tak District, Thung Kracho , alt. 700 m, 10 June 2020, Nattapon Nopporncharoenkul NNSB - 781 ( SLR!); ibid., alt. 480 m, 19 May 2023, Nattapon Nopporncharoenkul NNSB -916 (QBG-living specimen!, SLR!).

Note — Morphologically, K. subglobosa can be confused with the most similar looking species, K. rotunda , because they share the same overall habit, variegated leaves, inflorescences and flower colour. Kaempferia subglobosa can easily be distinguished from all other known species in subg. Protanthium by having the branched storage roots with numerous, tiny, lateral and terminal subglobose to ovoid tubers (vs storage roots not branched consisting of a single, large, terminal fusiform, ellipsoid to ovoid tuber). Kaempferia subglobosa differs also from K. rotunda in having 7–14 mm long opaque ligules (vs 1–3(–5) mm long translucent ligules), a narrowly obovate labellum with an inci- sion around 1/3 of its length (vs an obdeltoid to broadly obovate labellum with an incision around 1/2 of its length), and an anther crest with a bifid apex with apices aristate, incision serrate to undulate, incision base angular (vs anther crest with a bilobed apex with apices acute, incision entire, usually with 2–3 small teeth between incision base), as shown in Table 2. During our observations at and around the type locality, we found good fruit set with numerous viable seeds at the end of the flowering season. This evidence indicates that K. subglobosa has high fertility and sexual productivity in its natural habitat.