Volume 16 > Part 2 > Year 2023 > Page 380 > Zingiberaceae > Boesenbergia

1. Boesenbergia alba (K.Larsen & R.M.Sm.) Mood & L.M.Princewfo-0001342429

Gard. Bull. Singapore 66(2): 230. 2014.— Caulokaempferia alba K.Larsen & R.M.Sm., Notes Roy. Bot. Gard. Edinburgh 31(2): 288. 1972.— Jirawongsea alba (K.Larsen & R.M.Sm.) Picheans., Folia malaysiana 9(1): 3. 2008. Plate XLV: A.

Accepted Name : This is currently accepted.

Synonyms & Citations :

Description : Deciduous, perennial herb to 60 cm tall, several stems per clump; perennating organ a bud-crowned tuberous root, cylindrical, 1–3 by 1 cm, often several attached together at proximal end, externally and internally white; roots prolific, 1–4 mm diam., white, short roots covering tubers; stems erect, to 54 cm long, 5 mm diam., internodes variable, 3–15 cm long. Leafy sheaths: leafless sheaths 2, to 22 cm long, green or reddish, glabrous; sheaths to 30 cm long, glossy green, glabrous; ligule bilobed, to 2 mm, sometimes asymmetrical, green, becoming papery; blades ensiform, to 24 by 3 cm, above dark green, velvety, glabrous, below light green, glabrous, base rounded to truncate, apex acuminate; petiole 1–3 cm long. Inflorescence terminal, clasped by terminal leaf sheath; peduncle 1 cm, green; spike cylindrical, 8 cm long, 5 mm diam.; bracts distichous, ensiform, 3–5 by 0.5 cm, light green, glabrous; bracteoles ensiform, to 2 cm, translucent, glabrous. Flowers 4–6, to 9 cm long; ovary cylindrical, 8 mm long, 2 mm diam., white, glabrous; style filiform, ca 8 cm long, white; stigma a flat disc, translucent, ostiole circular, ciliate; epigynous glands ca 3 mm long; calyx to 2 cm, translucent, glabrous, apex dentate; floral tube to 6 cm long, white, glabrous, dorsal and lateral corolla lobes oblong, ca 2.5 by 0.5 cm, white or light violet, glabrous, apex cucullate, androecial cup absent; labellum orientated 90° to floral tube, flat to slightly concave, orbicular, 3–4 cm diam., base narrow, channelled, ca 1.5 by 1 cm, pure white with yellow streak at channel apex or light violet with yellowish throat, glabrous, apex entire or emarginate, margin slightly wavy; lateral staminodes obovate, often irregular in shape, sometimes asymmetrical, ca 3.5 by 1.5 cm, pure white or light violet, glabrous; stamen ca 1.2 cm long, yellow, glandular hairs full length; filament 2 mm long; anther ca 1 by 0.3 cm, yellow, thecae dehiscent full length, slightly divergent at apex, anther crest, ca 3 by 3 mm, bilobed, deflexed, yellow, pollen mucilaginous. Fruit cylindrical, ca 5 by 7 mm diam., light green, glabrous; seed ca 4 by 2 mm long, light green turning tan, hirsutulous, aril medusi-form, ca 3 mm long, white.

Thailand : NORTHERN: Phitsanulok (type of Caulokaempferia alba: Larsen 949, holotype -AAU); NORTH-EASTERN: Loei (type of C. thailandica: Smitinand 336, holotype -BKF; type of C. violacea: Triboun 399, holotype -BK).

Distribution : Laos.

Ecology : In full sun on sandstone plateaux at ca 1,200 m among small trees, bushes, ferns, mosses and grasses. Growing in spongy, accumulated leaf litter and moss with thin, sandy soil derived from the bedrock. Growth from May–October. Flowering: July–September.

Notes: Molecular phylogenetic evidence coupled with comparative morphological study of living material at their type localities show that Boesenbergia thailandica and B. violacea are indistinguishable from B. alba.