Kaempferia graminifolia Noppornch. & Jenjitt., 2018

Nopporncharoenkul, Nattapon & Jenjittikul, Thaya, 2018, Kaempferia graminifolia (subgen. Protanthium: Zingiberaceae), a new endemic species from Thailand, Phytotaxa 379 (3), pp. 261-266 : 261-265

Kaempferia graminifolia Noppornch. & Jenjitt. , sp. nov.

Diagnosis:—Similar to K. rotunda L. in floral shape, but obviously differs in having a unique linear grass-like foliage (vs. lanceolate-oblong to elliptic).

Type:— THAILAND. Sukhothai: Ban Dan Lan Hoi, Ban Dan, 110 m elevation, 26 September 2018, N. Nopporncharoenkul NNSB-684 (holotype BKF, isotypes BKF, BK, E, QBG, Suan Luang Rama IX herbarium (include spirit)) Fig. 1 , 2 & 3 .

Perennial herb. Rhizome subglobose to ovoid, 0.8–1.2 cm long, 0.8–1.5 cm in diameter; roots short fusiform, 1–2(–3) cm long, up to 1 cm in diameter. Leafy shoot 25–30(–40) cm tall with 5–7(–11) leaves, alternate distichous; pseudostem erect, 10–15 cm tall, 1–2.2 × 0.5–0.8 cm; bladeless sheaths 1–2, 4.5–5.5 cm long, green, apex acute, hairy; ligules bilobed, ca. 1 mm long, pale green, translucent, membranous, sparsely hairy; petiole 2–7 cm; lamina linear, 14.5– 33(–55) × 0.5–2(–4.5) cm; adaxially pale green to dull green, often with white or silver variegated pattern, glabrous; abaxially pale green (rarely dull purple), sparsely hairy; base attenuate; margin entire; apex acute. Inflorescence emerging directly from rhizome before the leafy shoots, narrow ovoid to conical, 3.5–7 cm long, 0.5–1.2 cm in diameter; peduncle 1.5–3.5 cm long, sparsely hairy; bracts ovate-lanceolate to narrow lanceolate, 3.5–4.5 × 0.6–1(–3) cm, apex acute to acuminate, green or purple, hairy. Flowers 2–7; calyx 3.5–5 cm long, 3–5 mm in diameter, split on one side ca. 1.2 cm from apex, apex tridentate, each tooth acute, pale green, semi-translucent, membranous, glabrous; corolla tube ca. 5.2 cm long, ca. 2.5 mm in diameter, white, glabrous; dorsal corolla lobe lanceolate-oblong, 3.5–4.5 cm × 4–5 mm, apex aristate (ca. 3 mm long), concave, hooded, white, glabrous; lateral corolla lobes lanceolate-oblong, 3.5–4 cm × 3–4 mm, apex aristate to acute, concave, white, glabrous; lateral staminodes oblanceolate to obovate, 3.5–4.2 × 1–1.5 cm, slightly arcuate, apex cuspidate to round, shallowly undulate, white; labellum broadly obovate, 3.2–3.8 × 2–2.5 cm, bilobed for half its length, each lobe obovate to suborbicular, 2 × 1.2–1.5 cm, apex cuspidate to round, shallowly undulate, partly overlapping, white with two purple stripes from base to sinus and spreading to each lobe. Stamen 15–18 mm long; filament flat, 2.8–3 × 1.5–2 mm, white, glabrous; anther thecae 4–6 × 1–1.2 mm; anther crest oblong to ovate, 6–10 × 4.5–5.5 mm, apex bilobed with (or without) 2–3 small teeth, apex of each tooth acute to obtuse. Pistil ca. 6.5 cm long. Ovary cylindrical, 3.3–5 mm long, 2–3.5 mm in diameter, trilocular, creamy yellow, glabrous; ovules numerous, placentation axile; epigynous glands 2, filiform, 5.5–6 mm long, creamy yellow. Style 5.5–6 cm long. Stigma funnel-shaped, 1–1.5 × 1.2–1.5 mm, stigma cup margin ciliate on front side, sparsely hairy on back side. Fruits trivalvate capsules. Seeds oblate to ellipsoid, 3.5–4 × 2–2.5 mm, yellow, with fleshy white laciniate aril.

Phenology:— Flowering occurs at the beginning of the rainy season (late May–June). Leaves usually emerge in early June around a week after the last flower blooms. Fruit matures around July.

Ecology:— This species grows in dry deciduous forest, mostly secondary forest, on low hills (100–120 m elevation), specifically growing on fine sand in areas with full sun to partial shade.

Distribution & IUCN preliminary assessment:— Kaempferia graminifolia is endemic to Northern Thailand. At present, this species is only known from four populations in Kamphaeng Phet and Sukhothai Province. During our observations, only a few hundred mature individuals in each population were encountered in the restricted area (less than two km 2). Furthermore, most of the populations are found in secondary forests along the road and close to the expansive areas of cassava plantation that may be threatened and contributed to population deterioration in the near future. Therefore, we propose to treat this new endemic species as Vulnerable (VU D1 and D2) following the categories and criteria of IUCN version 13 (2017).

Etymology:— The specific epithet “ graminifolia ” refers to the unique, linear, grass-like foliage.

Vernacular names: —This species is locally called “dok din bai khao” [dok din = flower which occurs on the ground, bai khao = rice leaves]. The name refers to the leaf shape of K. graminifolia , which is morphologically similar to that of rice or wild grass.

Additional specimens examined:— THAILAND. Kamphaeng Phet: Pran Kratai , 16 July 2016, N. Nopporncharoenkul NNSB-480 (Suan Luang Rama IX herbaria-spirit) ; 27 September 2018, N. Nopporncharoenkul NNSB-686 (QBG-living specimens). Sukhothai: Amphoe Mueang Sukhothai, 30 May 2017, N. Nopporncharoenkul NNSB-516 ( BKF) ; Ban Dan Lan Hoi , 11 June 2011, S. Sangvirotjanapat QBG-20135517 (QBG-living specimens) ; 13 September 2016, N. Nopporncharoenkul NNSB-495 ( BKF) ; 30 July 2017, N. Nopporncharoenkul NNSB-566 ( BKF) ; 14 June 2018, N. Nopporncharoenkul NNSB-657 ( BKF) 3 August 2018, N. Nopporncharoenkul NNSB-675 (QBGliving specimens) ; Khiri Mat , 19 September 2016, N. Nopporncharoenkul NNSB-497 ( BKF) .

Note: — Kaempferia graminifolia is another precocious flowering Kaempferia species from Northern Thailand, belonging to subgen. Protanthium. The unique, linear, grass-like laminae of this species readily distinguish this species from all other precocious flowering Kaempferia taxa. The leaf width/length ratio of K. graminifolia (1:14–1:36) differentiate it from the most morphologically similar species, K. rotunda (1:2–1:10). The flowering period of K. graminifolia (late May–early June) also differs from that of K. rotunda (April–May). Moreover, there are no other precocious flowering Kaempferia taxa have been found in geographically restricted areas of K. graminifolia , indicating this new endemic species has high specificity of habitat.

Figures

FIGURE 1. Kaempferia graminifolia. A. Habitat in August (arrows show K. graminifolia). B. Inflorescences with flowers in June. C–D. Plants in habitat; C. Mature plants. D. Seedlings. Photographed by N. Nopporncharoenkul (A. and C–D.) and W. Buranapattama (B).

FIGURE 2. Kaempferia graminifolia. A. Habit (vegetative part). B. Inflorescence and flower. C–E. Flower dissection; C. Calyx. D. Corolla tube with stamen and pistil. E. Corolla lobe (cl), lateral staminode (ls) and labellum (l). F. Detail of anther (front and side views). G. Detail of pistil (from left): pistil, stigma and style (front and side views) and ovary with stylodial glands. H. Germinated seeds. Photographed by N. Nopporncharoenkul.

FIGURE 3. Kaempferia graminifolia. A. Habit (vegetative part). B. Plant with inflorescence and flower (side view). C. Flower (front view). D. Calyx tube (undissected and dissected). E. Dorsal corolla lobe. F. Lateral corolla lobe. G. Lateral staminode. H. Labellum. I. Stamen with stigma, and some part of style and corolla tube (front and side views). J. Anther crests (with variable apex shapes). K. Stigma with some part of style (front and side views). L. Ovary and stylodial glands with some part of style (front and side views). Drawn by N. Nopporncharoenkul.