Vanoverberghia rubrobracteata Docot & Ambida

Docot, R. V. A., Banag, C. I., Tandang, D. N., Funakoshi, H. & Poulsen, A. D., 2019, Recircumscription and revision of the genus Vanoverberghia (Zingiberaceae), Blumea 64 (2), pp. 140-157 : 149

Vanoverberghia rubrobracteata Docot & Ambida — Fig. 5 ; Map 1

Vanoverberghia rubrobracteata Docot & Ambida (in Ambida 2018) 130. — Type: R.V.A. Docot 0123 (holo PNH accession no. 256337; iso E, NY, SING,USTH), Philippines,Luzon. Quezon, Tayabas, Barangay Lalo , Mount Banahaw , N14°03'43.9" E121°29'34.1", 1432 m, 12 Nov. 2017.

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

Terrestrial herb in loose or dense clumps. 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 bulbose, 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 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, puberulous, red; floral bract spathaceous, tubular at base, glabrous, 35–40 by 5–10 mm when flattened, red, apex pubescent; flower bud cylindrical; flowers congested along rachis; calyx funnel-shaped, 15–18 mm long, glabrous, coriaceous, red, apex tridentate; corolla tube 10–15 mm long, glabrous, coriaceous, white or pink; dorsal corolla lobe linear-oblong, 55–60 by 6–8 mm, glabrous, white or 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 connate to base of lateral corolla lobes, free part bifid, lobes subulate, 30–40 by 3–5 mm, white, base pubescent, apices of lobes entire; lateral staminodes filiform, 2–3 mm long, pubescent, white; filament enclosing style for almost half its length above 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, 1–2 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, brown with white aril.

Local names & Uses — Akbab (Igorot language), bagom- bong (Tagalog) and tagbak (Bisaya). The fruits are eaten by the locals and reported to have a sweet and sour flavour.

Phenology — Flowering takes place between October and January. Fruiting is between February and May.

Distribution & Habitat — Vanoverberghia rubrobracteata is endemic in the Philippines where it is distributed in the provinces of Antique, Aurora, Capiz, Ifugao, Mountain Province, Quezon, Negros Occidental and Rizal. It inhabits primary forests along streams and ravines from 800–1600 m.

Additional specimens examined. PHILIPPINES, Luzon, R. V .A. Docot 0089 ( USTH [2 sheets] incl.spirit), Aurora, Dingalan, Barangay Davil-Davilan, Mingan Mountains , Mount Mingan , 8 June 2016 ; R.V.A. Docot 0106 ( NY, USTH incl. spirit), Aurora, Dingalan, Barangay Davil-Davilan, Mingan Mountains, Mount Mingan , N15°26'25.6" E121°24'04.2", 1339 m, 17 June 2017; 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 , 25 Apr.2016 ; A. Loher 7028 ( K), Rizal, 1906 ; A. Loher 7006 ( K), Rizal, Montalban ,1906 ; B.F. Herman 5452 ( CAHUP), Sorsogon, Bacon, Pocdol Mountains , PNOC Geothermal Project site, 5 Jan. 2001 ; Visayas, R. V .A. Docot 0118 ( L, NY, USTH incl.spirit), Antique, Culasi, Barangay Flores, Mount Madjaas , 17 Oct.2017 ; M. Ramos & G. Edaño 30734 ( BM, BO, K, P), Capiz, Mount Madjaas , Apr.-May 1918 .

Note — Ambida et al. (2018) listed A.D.E. Elmer 17095 and 17383 from Mount Bulusan, Sorsogon under this species. Examination of recent collections (R.V.A. Docot 0133, 0198 & 0209; Fig. 2b ) with flowering material from this locality reveals that this population belongs rather to V. sepulchrei than to V. rubrobracteata . The populations of V. sepulchrei in Mount Bulusan, however, differ only slightly from the northern Luzon populations by having subsessile leaves (vs petiolate). Accepting this variation extends the distribution of V. sepulchrei to the far south of Luzon (see Map 1 ). The fruiting specimen B.F. Herman 5452, also from Sorsogon, needs to be compared with new collections from its locality to confirm whether it is also V. sepulchrei . This specimen is here placed, tentatively, under V. rubrobracteata .

Figures

Map 1 Distribution of Vanoverberghia diversifolia Elmer (▲), V. rubrobracteata Docot & Ambida (★), V. sasakiana Funak. & H.Ohashi (◆); V. sepulchrei Merr. (■) and V. vanoverberghii (Merr.) Funak. & Docot (●).

Fig. 5 Vanoverberghia rubrobracteata Docot & Ambida. a. Ligule; b. inflorescence;c. flower at anthesis; d. infructescence (a–c: R.V.A. Docot 0123; d: without voucher) — Photos: a–c. R.V.A. Docot; d. H. Funakoshi.

Fig. 2 a. Vanoverberghia sasakiana Funak. & H.Ohashi. from Solsona, Ilocos Norte; b. Vanoverberghia sepulchrei Merr. from Mount Bulusan, Sorsogon (a: J.R. Callado s.n.; b: R.V.A. Docot 0209). — Photos: a. J.R. Callado; b. R.V.A Docot.