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| Curcuma pitukii Maknoi, Saensouk, Rakarcha & Thammar., in Maknoi, Saensouk. ... et Thammarong, 2021. |
Abstract
Curcuma aruna and C. pitukii, two new species from northern Thailand, are described, illustrated, and photographed. They are endemic to Sukhothai and Lampang Provinces, northern Thailand, and the morphological characteristics of two new species are compared with their closest species, C. flaviflora, C. eburnea, and C. pierreana. Two new species, C. aruna and C. pitukii are assignable to Curcuma subgenus Ecomata. C. aruna is recognized by leaves ovate with thin chartaceous, fertile bracts 6–12, it’s glabrous on nearly all parts of the plant, flowers yellow and labellum yellow with 2 darker yellow bands in the center. C. pitukii is recognized by bracts 20–40 with purplish white to purple, corolla lobes purplish white to pale purple, staminodes white, and labellum white with an embossed yellow path along the midrib from base to apex. A detailed description, distribution, ecology, etymology, preliminary conservation status, and photographs of two new species are provided. A key to 20 species of Curcuma subgenus Ecomata in Thailand is presented.
Keywords: Curcuma flaviflora, C. eburnea, C. pierreana, Lampang, subgenus Ecomata, Sukhothai, taxonomy, Zingiberales
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| Curcuma aruna Maknoi & Saensouk: A. and B. habit; C. inflorescence; D. flower in front view; E. flower in side view; F. flower dissection (from left: abaxial of bract, adaxial of bract, calyx, floral tube with stamen, ovary with epigynous gland, lateral staminode, labellum, dorsal and lateral corolla lobes). Photographed by C. Maknoi (A, C from type location); S. Rakarcha (B, D–F from cultivation) |
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| Comparison of Curcuma aruna and C. flaviflora. C. flaviflora: A. habit; B. inflorescence; C. corolla tube with ovary, calyx, and stamen; E. flower dissection (from left: lateral staminode, labellum, stamen in front view, and stamen in side view). C. aruna: D. corolla tube with ovary, calyx and stamen; F. flower dissection (from left: lateral staminode, labellum, stamen in front view and stamen in side view). Photographed by W. Pongamornkul (A, B from Doi Ang Khang, Chiang Mai, N. Thailand); S. Rakarcha (C, E from Maknoi 356 (QBG); D, F from cultivation) |
Curcuma aruna Maknoi & Saensouk, sp. nov.
subgenus Ecomata
This species is similar to C. flaviflora in early flowering habits, short peduncle, no coma and yellow flowers. The leaves of C. aruna are ovate and glabrous on both surfaces, instead of leaves elliptic to oblanceolate and pubescent on both surfaces in C. flaviflora. The length of the corolla tube of C. aruna is shorter than in C. flaviflora (2.3–2.8 cm long in C. aruna vs 3.8–4.2 cm in C. flaviflora). The staminodes of C. aruna are obovate, whilst those of C. flaviflora are ovate to elliptic. The staminodes of C. aruna are larger than those of C. flaviflora (2.2–2.6 × 1.4–1.6 cm in C. aruna vs 2.0 × 1.2 cm in C. flaviflora).
Etymology: The specific epithet of the new species is “aruna”, which means “dawn” in Thai, refer to flower color resemble the color of the dawn and name of God of the Dawn in Thai mythology. The name of the type locality province “Sukhothai” means the dawn of happiness also.
Vernacular name: Krachiao Arun - กระเจียวอรุณ
(Krachiao in Thai means Curcuma and arun means dawn in Thai).
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| Curcuma pitukii Maknoi, Saensouk, Rakarcha & Thammar.: A. habit; B. inflorescence; C. close up flowers; D. inflorescence (top view); E. rhizome and roots (inset: detail of rhizome and root tubers); F. leaf. Photographed by S. Rakarcha. |
Curcuma pitukii Maknoi, Saensouk, Rakarcha & Thammar., sp. nov.
subgenus Ecomata
Curcuma pitukii is most similar to Curcuma eburnea Škorničk., Suksathan & Soonthornk. by its terminal inflorescence, the number of bracts, without coma bracts, and small filiform anther spurs. The leaves of C. pitukii are densely puberulent on the adaxial surface, but the leaves of C. eburnea are glabrous on the adaxial surface. C. pitukii has purplish white to purple bracts, whilst C. eburnea has cream-white or pale greenish bracts. The length of the calyx of C. pitukii is longer than in C. eburnea (14–18 mm long in C. pitukii vs 8–10 mm long in C. eburnea). The length of the corolla tube of C. pitukii is shorter than in C. eburnea (2.2–3 cm long in C. pitukii vs 3.5 cm long in C. eburnea). The corolla lobes of C. pitukii are purplish white to pale purple and sparsely puberulent at the apex, but in C. eburnea they are pure white and glabrous. The length of the filament of C. pitukii is longer than in C. eburnea (5–8 mm long in C. pitukii vs 2 mm long in C. eburnea). The length of the anther of C. pitukii is shorter than in C. eburnea (2.5–4 mm long in C. pitukii vs 8–9 mm long in C. eburnea).
Etymology: The specific epithet “pitukii” is named in honor of “Mr. Pituk Punyajun”, a supporter and backup plant taxonomists in Thailand for over 25 years and who first found the plant.
Vernacular: Cho Muang Pituk - ช่อม่วงพิทักษ์
(Cho in Thai name means inflorescence, Muang means purple, and Pituk is the first name of Mr.Pituk Punyajun).
Charun Maknoi, Surapon Saensouk, Piyaporn Saensouk, Sarayut Rakarcha and Woranart Thammarong. 2021. Two New Species of Curcuma L. (Zingiberaceae) from Thailand. Biodiversitas. 22; 3910-3921. DOI: 10.13057/biodiv/d220937
