Globba corniculata Y. Ritu & V. Gowda, 2024

Yadav, Ritu & Gowda, Vinita, 2024, Six new species of Globba L. (Zingiberales, Zingiberaceae) from the Eastern Himalayas and Northeast India, PhytoKeys 246, pp. 197-228 : 197-228

Globba corniculata Y. Ritu & V. Gowda sp. nov.

Fig. 4

Type.

India. West Bengal: Darjeeling district, Takdah forest , 27.0493, 88.3555, elevation 1220 m, 20 August 2022, Y. Ritu, S. Goray & Rhuthuparna S. B. VG 2022 WB 3803 (holotype: BHPL!; isotype: ASSAM!) .

Diagnosis.

Globba corniculata is morphologically similar to G. ruiliensis and G. multiflora but differs in having sessile, oblong-narrowly ovate leaves, absence of inflorescence bracts and bracteoles, orange flower, cuneate labellum with cornicula (Fig. 4 F ), long pedicel, the presence of bulbils throughout the inflorescence vs. petiolate, ovate to narrowly ovate leaves, presence of inflorescence bracts and bracteole, yellow to orange flowers, and obcuneate labellum with cornicula.

Description.

Terrestrial herbs, 100–160 cm tall including inflorescence height, pseudostem swollen at the base. Rhizomes compact, non tuberulous, creamish white. Leafy shoot with 9–12 leaves; sheath ligulate, ligule 3 mm long, bilobed, margin densely pubescent; lamina 25–32 × 6–10 cm, sessile, oblong – narrowly ovate, base rounded, apex caudate, margin entire, adaxially pubescent along veins and margins, abaxially densely pubescent. Inflorescence terminal to the leafy shoot, 25–53 cm long, erect; peduncle 18–23 mm long, light green, glabrous; rachis, dark green, glabrous, with white dots, bracts and bracteole absent. Ebracteate cincinni 25–51, flowers maturing from base to apex of inflorescence, each cincinni with 2–3 flowers. Floral pedicel for basal flowers 2.2–2.7 cm long, for terminal flowers 0.4–0.6 cm long, dark green, white dotted, glabrous. Flowers 4.2–4.9 cm long, orange, recurved; calyx 9–10 mm long, pale yellow with maroon patches; floral tube 1.5–1.8 cm long, dark orangish red, densely pubescent, curved upwards holding the flower upright; dorsal corolla lobe 8–9 × 3–4 mm, ovate, apex cucullate, dark maroon with orange tip, densely pubescent; lateral corolla lobes 7–8 × 5–5.5 mm, ovate, apex acute, dark maroon with orange apex, glabrous; labellum 1.3 × 0.6–0.8 cm, cordate, corniculate, orange, linear structures scattered on ventral surface; lateral staminodes 9–10 × 3–4 mm, narrowly ovate, apex attenuate, orange, glabrous. Stamen 2.1–2.4 cm long, filament 1.5–1.8 cm long, orange tinged red, glabrous, fulvous with red dots, arching; anther 5–6 mm long, ovate, apex acute, orange tinged red, crest 0.8–0.9 mm long, non-appendaged; style 4.3–4.8 cm, filiform, apex broader than base, stigma 4–5 mm long, cylindrical, apex ciliate. Ovary 0.4–0.5 × 0.3 cm, obovate, pale green, verrucose; epigynous glands 2, 0.4–0.5 cm long, linear, cream. Fruit 1.5 cm in diameter, globose, green, verrucose, calyx persistent. Bulbils 1.2–2 × 0.5–0.8 cm, narrowly ovoid, yellowish green with dark maroon lines, pubescent, bulbils often at the base within a cincinni, but present throughout the inflorescence.

Distribution and ecology.

At present, G. corniculata is known only from the Takdah Forest in West Bengal, which is a tropical evergreen, lower montane forest at an elevation of ca. 1220 m. It is terrestrial, mostly growing in open habitats along the edge of roads. The current location has ca. 70 individuals within an area of ca. 400 m 2. Other sympatric ginger species were G. racemosa and Hedychium spicatum Sm. We have observed several species of bees and butterflies visiting the flowers of this species.

Phenology.

Flowering and fruiting were observed in the month of August.

Etymology.

The species epithet ‘ corniculata ’ refers to the presence of horn-shaped structure at the base of labellum.

Informal conservation status.

G. corniculata is known only from one population, which is a protected area with limited or no anthropogenic disturbance. The population was spread across 2–3 km along the edge of the road, where we counted 1500–2000 individuals. We surveyed six potential locations in Darjeeling, which is 50 km 2 around the type locality (Takdah forest) and could not locate any population in northern West Bengal. Based on the IUCN (2022) guidelines, we hypothesize that if a formal conservation assessment were performed, its conservation status would probably be Critically Endangered according to criteria B 1. (a) (B 1: extent of occurrence is less than 100 km 2, a: = 1 location).

Specimens of allied species examined.

G. ruiliensis : China. Yunnan Province: Ruili City, Nongdao Town, Dengga village, 23.95 N, 97.55 E, elevation 854 m, 21 October 2019, Jian-Yong Shen, Wen-Guang Wang & Xing-Da Ma 1666 (holotype: HITBC!)

G. multiflora : India. Sikkim: Regio Trop, ( PL 0092 1837), (P 01743164). Assam: Khasia Hills ( L 0487990), Khasi Hills, Nambar Forest, 3 July 1949, elevation 91.44 m, F. Kingdon-Ward 18619 ( NY 02650821), Jenkins F Jenkins, F s. n. ( L 0487989).

Taxonomic notes.

The new species is similar to the two species in flower color and presence of cornicula at the base of the labellum. The new species differs from G. ruiliensis in its large inflorescence 25–53 cm (vs. 10–35 cm), short peduncle 1.8–2.3 cm (vs. 3–15 cm), glabrous rachis (vs. hirsute) and absence of inflorescence bracts (vs. present). The new species differs from G. multiflora in its large lateral staminodes 9–10 mm (vs. 3–4 mm), length of lateral staminodes equal to corolla lobes (vs. shorter than corolla lobes), and production of bulbils throughout the inflorescence (vs. only at the lower portion of inflorescence). The detailed morphological comparisons between G. corniculata and G. ruiliensis , G. multiflora are presented in Table 1 .

Notes.

G. ruiliensis is distributed in Yunnan province, China and G. multiflora is distributed in Meghalaya, Assam, and Sikkim states, India and Bangladesh (Fig. 5 ).

Figures

Figure 4. Globba corniculata sp. nov. A habit B rhizome C, D ligule E inflorescence F flower (front view) G flower (side view) H gynoecium I dissected flower, cl (corolla lobes), an (anther), ls (lateral staminodes), la (labellum) J fruit. Photographs by Y. Ritu.

Figure 5. Map showing the distribution of G. multiflora, G. ruiliensis, and G. corniculata sp. nov.