Vanoverberghia rubrobracteata Docot & Ambida, 2018

Ambida, J. H. B., Alviar, A. M. A., Co, P. S. A., Concepcion, F. G. M., Banag, C. I. & Docot, R. V. A., 2018, A new species of Vanoverberghia (Zingiberaceae) from the Philippines, Blumea 63 (2), pp. 130-134 : 130-134

Vanoverberghia rubrobracteata Docot & Ambida , sp. nov. — Fig. 1–3 ; Map 1

Similar to Vanoverberghia sepulchrei Merr. but differs in the shape of the lamina (oblong to narrowly elliptic not oblong only), shape of the ligule apex (unevenly truncate not rounded), surface and colour of the floral bracts (glabrous and red not pubescent and white), colour of the calyx (red not pinkish white), colour of the corolla tube and lobes (white or pink not white only), and absence of spots on the style. — Type: R. V. A. Docot 0123 (holo PNH no. 256337; iso E, NY, SING, USTH), Philippines, Luzon , Quezon, Tayabas , Barangay Lalo , Mount Banahaw , N14°03.561' E121°31.157', 1 432 m, 12 Nov. 2017 .

Etymology. The specific epithet refers to the red floral bracts.

Terrestrial herb in loose or dense clump. Rhizome 25–50 mm across, red, strongly aromatic when cut, scales thick, brown. Leafy shoot arching at various degrees, pseudostem 4–6 m long, base bulbous, 3–5 cm across, red; sheaths glabrous, green; ligule ovate, 20–30 mm long, coriaceous, glabrous, red, apex unevenly truncate and entire; petiole terete, 10–13 mm long; lamina oblong to narrowly elliptic, 50–51 by 11–15 cm, veins obscure, dark green above, lighter beneath, glabrous on both sides, base rounded, margin entire, apex caudate with a 20–30 mm long flagellate tip. Inflorescence a terminal raceme, pendulous, 25–35 cm long; peduncle terete, 10–20 cm long, glabrous, deep red, subtended by 2–3 persistent bracts; rachis 7–15 cm long, glabrous, deep red; pedicel terete, 3–5 mm long, slightly puberulous, red; floral bract spathaceous, tubular at the base, glabrous, 35–40 by 5–10 mm when flattened, red, apex pubescent; bracteole absent; flower buds cylindric; flowers congested along the rachis, one per floral bract; calyx funnel-shaped, 15–18 mm long, glabrous, coriaceous, red, apex 3-dentate; corolla tube 10–15 mm long, glabrous, coriaceous, white or pink; dorsal corolla lobe linear-oblong, 55–60 by 6–8 mm, glabrous, white to pink, apex rounded and cucullate; lateral corolla lobes linear-oblong, 55–60 by 3–5 mm, glabrous, white or pink, apex rounded and cucullate; labellum

Map 1 Distribution of Vanoverberghia rubrobracteata Docot & Ambida (*), V. sasakiana Funak. & H.Ohashi (◆) and V. sepulchrei Merr. (■).

connate to the base of lateral corolla lobes, free part bifid, the lobes subulate, 30–40 by 3–5 mm, white, base pubescent, apices of lobes entire; lateral staminodes filiform, 2–3 mm long, slightly pubescent, white; stamen 68–71 mm long, curved at anthesis; filament canaliculate and enclosing the style for almost half its length above the labellum, 53–55 by 2–3 mm, slightly glandular, cream-white; anther oblong, 15–16 by 2–3 mm, sericeous, crestless, thecae pubescent; style 4–6 cm long, glabrous, white; stigma cupular, 1–2 mm wide, white, ostiole elliptic, margin hispid; epigynous glands compressed, subglobose, 1.5–2 mm long; ovary subglobose, 4–7 by 2–3 mm, coriaceous, glabrous, deep red. Fruit ellipsoid to subglobose, 20–25 by 15–20 mm, coriaceous, glabrous, deep red when mature, calyx persistent. Seed subglobose, 1–2 mm across, brown with white aril.

Vernacular names — Akbab (Igorot language), Bagombong (Tagalog), and Tagbak (Bisaya).

Uses — The fruits are eaten by the locals and were reported to have a sweet and sour flavour like V. sepulchrei ( Docot et al. 2016) .

Phenology — Flowering: between October and January; fruiting: between February and May.

Distribution & Habitat — Vanoverberghia rubrobracteata is endemic to the Philippines and occurs in the provinces of Antique, Capiz, Ifugao, Quezon, Mountain Province, Negros Occidental, Rizal, and Sorsogon (Map 1). It inhabits montane forests along streams and ravines from 1 000–1 600 m.

Conservation status — Vanoverberghia rubrobracteata is abundant within the montane forest of the eight localities, three of which are protected areas in the Philippines (e.g., Mount Banahaw-San Cristobal Protected Landscape). The population of the species, however, may decline if expansion of agricultural (e.g., vegetable plantations) and residential areas within the forests of each locality is continuously practiced. Therefore, V. rubrobracteata is preliminary assessed here under the Least Concern (LC) category.

Additional specimens examined.

Vanoverberghia rubrobracteata . PHILIPPINES, Luzon,* A. Loher 7028 ( K), Rizal, 1906 ; * A.D. E. Elmer 17095 ( BO, P, S, US), Sorsogon, Irosin, Mount Bulusan , Aug. 1916 ; * A.D. E. Elmer 17383 ( BO, P, US), Sorsogon, Irosin, Mount Bulusan , Sept. 1916 ; D. N. Tandang & R. T. Angeles s.n. ( PNH), Ifugao, Banaue , 22 Jan. 2013 ; R. V. A. Docot 0049 ( USTH [2 sheets] incl. spirit), Quezon, Tayabas, Barangay Lalo , Mount Banahaw , 25Apr.2016 . – Visayas, * M. Ramos & G. Edaño 30734 ( BO, P), Capiz, Mount Madjaas , Apr.–May 1918 ; R. V. A. Docot 0118 ( NY, USTH incl. spirit), Antique, Culasi, Barangay Flores , Mount Madjaas , 17 Oct. 2017 .

Vanoverberghia sepulchrei . PHILIPPINES, Luzon, P. T. Barnes 947 ( SING), Benguet, Baguio, May–June 1904 ; * A.D. E. Elmer 8560 ( BO, SING, US), Benguet , Baguio, Mar. 1907 ; * M. Vanoverbergh 956 ( BM, US), Bontoc , Mountain Province, 19 Oct. 1910 ; * M. Ramos & G. Edaño 45045 ( BO, P, SING), Benguet , Baguio, Mar. 1925 ; H. C. Conklin & Buwaya I­984 ( L [2 sheets], PNH), Bayninan , Banaue, Ifugao, 6 Mar. 1963 ; R. V. A. Docot 0001 ( USTH [2 sheets]), N17°03.293' E120°57.372', Mount Data , Barangay Alab-Oriente , Bontoc, Mountain Province, 1 Nov.2013 ; R. V. A. Docot 0027 ( USTH! [3 sheets] incl.spirit), Mount Data , Barangay Alab-Oriente , Bontoc, Mountain Province, 9 Jan. 2016 ; R. V. A. Docot 0122 ( PNH, USTH incl. spirit), Mount Data , Barangay Alab-Oriente , Bontoc, Mountain Province, 5 Nov. 2017 . – Cultivated material from Lyon Arboretum, Honolulu, Hawaii:* Anon L­87.0651 ( E [4 sheets], US) 1995; * J. Mood 46 ( E), 15 June 1998 ;* J. Mood 47 ( E), 16 July 1995 .

Notes — Vanoverberghia rubrobracteata and V. sepulchrei both occur in the provinces of Ifugao and Mountain Province. The population of the new species in these two provinces which are located more northerly, however, are quite distinct from the populations distributed more southerly by having pink corolla tube and lobes (vs white) ( Fig. 3a, b ). Since only the colour of the corolla tube and lobes was found to be different, this study cannot warrant the populations from Ifugao and Mountain Province to be recognized as a separate species nor a variety.

Figures

Fig. 1 Vanoverberghia rubrobracteata Docot & Ambida. a. Habit; b. ligule; c. inflorescence; d. leaf apex; e. flower at anthesis; f. mature fruit; g. flower (all from type locality). — Scale bars = 1 cm. — Photos by R.V.A. Docot. Abbreviations: an: anther; br: bracts; ca: calyx; dc: dorsal corolla lobes; fl: flower; lc: lateral corolla lobes; la: labellum; nc: nectaries (epigynous glands); ov: ovary; pe: pedicel; sg: stigma.

Fig. 2 Vanoverberghia rubrobracteata Docot & Ambida.a. Floral bract; b. calyx;c. dorsal corolla lobe; d. lateral corolla lobes;e. labellum;f. filament and lateral staminodes; g. anther (front view), notice also the style and stigma; h. anther (back view). — Scale bars = 1 cm. — Drawing by G. Campos.

Fig. 3 Vanoverberghia rubrobracteata Docot & Ambida. a. Mountain Province; b. Ifugao; c. Negros Occidental; d. Antique (a, c: without voucher; b: D.N. Tandang & R.T. Angeles s.n.; d: R.V.A. Docot 0118). — Photos by: a. H. Funakoshi; b. D.N. Tandang; c. P.B. Pelser; d. R.V.A. Docot.