Zingiber sabuanum K.M.P.Kumar & A.Joe, 2016
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publication ID |
https://doi.org/ 10.11646/phytotaxa.247.1.7 |
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persistent identifier |
https://treatment.plazi.org/id/03B82B7A-4324-FF8E-6BDC-FB28FEE3F7A8 |
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treatment provided by |
Felipe |
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scientific name |
Zingiber sabuanum K.M.P.Kumar & A.Joe |
| status |
sp. nov. |
Zingiber sabuanum K.M.P.Kumar & A.Joe View in CoL , sp. nov. ( Figure 1 View FIGURE 1 & 2 View FIGURE 2 )
Similar to Zingiber rubens but differs in having stoloniferous rhizomes, purple pseudostems, long ligules, 2.5–3.4 cm, bracts with purplish apex and greenish base, apex curved inwards, maroon labellum with white dots or stripes and orange-purple lateral staminode with cream dots. In Z. rubens , rhizomes are non-stoloniferous, greenish pseudostem with small ligule upto 0.6–1.2 cm, bright red bracts, apex curved out wards, white labellum with red stripes and yellow lateral staminode with red dots.
Type:— INDIA. Kerala: Palakkad, Dhoni forest, near Dhoni waterfall, ± 300 m, 24 August 2011, K. M. Prabhukumar 95055 (holotype in CALI!, isotypes in MH!, CMPR!, CATH!).
Perennial, stoloniferous, rhizomatous herbs, not clump forming, spreading by running rhizomes. Rhizomes fleshy, densely branched, 0.7–1.5 cm diameter, cream. Root tubers fusiform, cream. Leafy shoots 70–80 cm, pseudostem purple, glabrous. Leaves up to 20 when flowering, sessile or subsessile, pulvinate. Laminae oblanceolate, 26.0–29.5 × 7.2–7.5 cm, adaxially green, glabrous, abaxially light green, tomentose, base cuneate, apex long-acuminate. Ligules 2.5–3.4 × 0.5–0.7 cm, base purple-hyaline towards apex and margins, apex bilobed, obtuse. Inflorescences one to three, radical, spicate, 5–12 cm, peduncle 1–6 cm, cream or greenish with cream or purplish sterile bracts at base, glabrous. Spikes ovate to obovate, consisting of 10–20 fertile bracts. Fertile bracts linear, 3.2–3.6 × 0.6–0.7 cm, apex purplish, curved inwards and oblique, base greenish, outer surface glabrous or hairy up to middle, inner surface glabrous and shiny, enclosing a single flower. Bracteoles oblong, 2.3–2.5 × 0.8 cm, cream or cream with green tinge at base, apex red or purplish, sparsely pubescent externally, glabrous internally, apex muticous or bifid with short hairs. Flowers 5.7–6.4 cm long. Calyx 1.3–1.4 × 0.6–0.7 cm, tubular with a unilateral split, white, externally pubescent, internally glabrous, apex almost truncate. Floral tube 2.6–2.8 cm long, base cream, apex creamy orange, externally puberulent; dorsal corolla lobe triangular-ovate, concave, 2.0–2.7 × 0.7–0.9 cm, creamy orange with translucent veins, glabrous internally and externally, apex acute, slightly hooded and mucronate. Lateral corolla lobes triangular-ovate, 2.3–2.5 × 0.5–0.6 cm, base cream, apex creamy orange with translucent veins, glabrous internally and externally, apex acute. Labellum ovate-oblong, 2.7–2.8 × 1.3–1.5 cm, purple with white line and numerous glandular hairs at middle and white dots at periphery, apex emarginated. Lateral staminodes obovate, 0.7–1 × 0.4–0.6 cm, connate to labellum, orange-purple with cream dots, apex mostly bifid. Stamen 2.1–2.4 cm long, filament reduced to c. 1 cm long, anther thecae 1.3–1.5 × 0.2–0.3 cm, cream, connective tissue orange yellow with purple dots towards apex, glabrous, anther crest (beak) 0.9–1.0 cm long, purple, wrapped around stigma, glabrous. Style filiform, white glabrous. Stigma cuplike, ostiole ciliate. Ovary cylindrical, 0.5–0.6 cm long, cream, densely pubescent, trilocular with central placentation. Epigynous glands 0.4–0.5 cm, cream, apex acute or truncate. Fruits cylindrical, without any ridges.
Phenology:— Flowering May to November.
Etymology:— The new species is named after Dr. M. Sabu, Professor, Department of Botany, Calicut University, for his contributions to the field of Indian Angiosperm Taxonomy especially the order Zingiberales .
Habitat and Ecology:— Zingiber sabuanum is known only from the type locality. The plants are growing in the understorey of evergreen forests up to a maximum elevation of 500 m.
Conservation status:— As the occurrence of this new taxon is found in highly restricted in 1–2 km 2 area, the species is likely to fall within a category of threat. At the time of first collection during 2010, we observed very good populations throughout the locality, but the subsequent field visits report a gradual decrease in the number of populations and number of individuals per population each year. This decline is due to various anthropogenic activities, mainly forest clearance and the creation of jungle paths for tourist access and for forest staff. Thus, based on the present knowledge and available data, conservation status is assessed as Critically Endangered (CR B1ab(i,ii,iv); 2ab(i,ii,iv); D; E) using IUCN Red List Categories and Criteria ( IUCN 2012). A good number of individuals are present ex-situ, in the Calicut University Botanical Garden.
Additional specimens examined (paratypes): — INDIA. Kerala: Palakkad, Dhoni forest, near Dhoni waterfall, ± 300 m, 7 July 2012, K. M. Prabhukumar & A. Joe 7035 ( CMPR!) ; Dhoni forest, near Dhoni waterfall, 7 July 2012, K. M. Prabhukumar & A. Joe 130874 ( CALI!) ; Dhoni forest, way to Korakkallu , ± 400 m, 26 September 2012, K. M. Prabhukumar 7570 ( CMPR!)
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