Globba luteola Sangvir., 2021

Sangvirotjanapat, Sunisa & Newman, M. F., 2021, Eight new species of Globba (Zingiberaceae) from Thailand and Lao PDR, Phytotaxa 505 (2), pp. 139-156 : 149

Globba luteola Sangvir. , sp. nov. (Section Ceratanthera )

This is similar to Globba leucantha Miq. ( Fig. 2B ) in its elongate cincinni with well-spaced flowers but differs by its flowers being pale yellow throughout with no spot (vs flowers combining violet, yellow and white), triangular labellum (vs oblong labellum), and truncate labellum base (vs long decurrent with short cornicula).

Type: Accession 20135668 A, cultivated at Queen Sirikit Botanic Garden, Zingiberaceae nursery, 14 June 2014, Sangvirotjanapat 641 (holotype QBG). Originally collected in THAILAND. Nakhon Si Thammarat, Khao Luang. Fig. 6 .

Herb c. 50 cm tall. Leaf sheaths c. 4 bladeless, pubescent, plain green; ligule shallowly bilobed, 2 mm long, green with paler margin; blades 7–10, elliptic, 13–25 × 3–6.5 cm, base cuneate or obtuse, apex acuminate, pubescent below, strigillose along veins above, sessile, green. Inflorescence erect, lax, conical, 6–16 × 3–9 cm; peduncle 1–2 cm long, green; rachis green; bracts caducous, elliptic, c. 3 × 2 mm, apex acute, yellow; bracteoles caducous, elliptic, c. 3 × 2 mm, hooded, keeled, yellow; cincinni lax, 1–3.5 cm long, green, 4–9 flowers on each, flowers 2–6 mm apart. Flowers c. 3 cm long; ovary ellipsoid, 2–3 mm long, green; style filiform; stigma geniculate, ostiole ciliate, usually protruding beyond anther thecae, semitransparent, white; calyx infundibuliform, c. 4 mm long, trilobed with acute apices, pale yellow; floral tube c. 8 mm long, hairy, yellow; dorsal corolla lobe elliptic, c. 7 × 2.5 mm, hooded, apex obtuse, pale yellow; lateral corolla lobes elliptic, 6 × 2 mm, shallowly hooded, apex obtuse, pale yellow; lateral staminodes oblong, c. 5 × 1.5 mm, apex acute, pale yellow; labellum oblong or narrowly obtriangular, c. 5 × 3 mm, base truncate, apex bilobed, lobes acute, pale yellow with no coloured spot; nectar tube c. 3 mm long; stamen: filament c. 25 mm long, pale yellow; anther elliptic, c. 2 × 2 mm, connective tissue and appendages semitransparent, yellow; appendages 2, triangular, c. 3 × 1 mm, held at c. 45° to anther thecae, base broad, apex acuminate. Fruit not seen. Bulbils not seen.

Etymology: Latin, luteola , pale yellow, referring to its flower colour.

Distribution: Endemic to Thailand.

IUCN assessment proposed: Data Deficient (DD). Globba luteola is restricted to Khao Luang, Nakhon Sri Thammarat province . It is rare in herbaria. There is only a single collection from the type locality so further surveys are needed to assess this species, which is currently Data Deficient .

Ecology: Grows in high humidity and partial shade.

Note: Globba luteola is recognised by its pale yellow flower with short labellum and small lateral staminodes. The lateral staminodes are shorter than the lateral corolla lobes.

Figures

FIGURE 2. A. Globba expansa Wall. ex Horan. B. G. leucantha Miq. C. G. nisbetiana Craib. Photographs by S. Sangvirotjanapat.

FIGURE 6. Globba luteola Sangvir. (Sangvirotjanapat 641) A. Habit B–C. Inflorescence D. Flower E. Flower dissection; lcl = lateral corolla lobe, dcl = dorsal corolla lobe, ls = lateral staminode, lb = labellum, at = anther thecae F. Anther and anther appendages, stigma protruding from anther thecae; at = anther thecae, st = stigma. Scale bars:A = 10 cm; B & C = 5 cm; D & E = 1 cm; F = 5 mm. Photographs by Sangvirotjanapat S.