Etlingera pubimarginata (Elmer) A.D. Poulsen (2018: 8)

Naive, Mark Arcebal K., Demayo, Cesar G. & Alejandro, Grecebio Jonathan D., 2019, Rediscovery and new data on distribution of the imperfectly known Philippine endemic Etlingera pubimarginata (Zingiberaceae; Alpinieae), Phytotaxa 394 (1), pp. 105-110 : 106-109

Etlingera pubimarginata (Elmer) A.D. Poulsen (2018: 8) Fig. 1

Basionym: Amomum pubimarginatum Elmer (1915: 2900) . Geanthus pubimarginatus (Elm.) Loesener in Engler & Prantl (1930: 593).

Type: — Todaya ( Mt. Apo ), District of Davao, Mindanao, Philippines, May 1909, A. D. E. Elmer 10546 (lectotype: BM [BM000630037], designated by Poulsen & Docot (2018); isolectotypes BISH-image!, BM-image!, BO, F-image!, G-image!, K-image!, L, MO-image!, NY-image!, US-image!) .

Description: Large terrestrial rhizomatous herb. Rhizome 2.3–2.5 cm in diameter, pubescent, scales 3–3.3 cm long, subcoriaceous, caducous, glabrous, striate, covering the rhizome, apex attenuate; stilt roots absent. Leafy shoots 1.5 to 3 m long, tips of the shoot ascending to drooping, composed of up to 30 leaves, 16–40 cm between neighbouring leafy shoots, leafless part 0.5–0.9 m; base 2.5–3 cm in diameter, dark olive green; sheath olive green, striate, not clearly cross-ribbed, with golden brown simple trichomes when young, glabrous when mature, margin membranous, reddish; ligule 6–8 mm long, entire, ovate, green to reddish green, with golden brown simple trichomes when young, becoming glabrous when matured, margin membranous, apex obtuse; petiole 1–1.8 cm long, reddish green, glabrous; lamina oblong to narrowly obovate, 33–45 cm × 8–10 cm, smooth, green, pale beneath, glabrous, margin entire, finely ciliate, base obtuse, apex acuminate; midrib adaxially chanelled, green, abaxially protruding, pale green. Inflorescence 8–13 cm long, arising from rhizome, embedded in the soil, receptacle dome–shaped, c. 5 cm long, with 8–10 flowers, 1 open at a time; peduncle 3.8–4.5 cm long, subterranean, appressed-pubescent, peduncular bracts 1.8–2.2 cm × 0.8–1 cm, upper covering base of spike, coriaceous, peach to reddish, glabrous, margin membranous, subapical mucro <1 mm; spike (including flowers) 4–6 cm long, obovoid to ovoid, flowers extending up to 2 cm above the bracts, spike only including bracts, these 4–5 cm × 2–3 cm; sterile bract 2 or 4, outer ones in line with peduncular bracts, ovate to boat-shaped, 3–4 cm × 1–1.5 cm, concave, margin entire, apex sharply pointed; fertile bract 2.3–4.0 cm × 0.5–1.6 cm, lanceolate to boat-shaped, apex attenuate, sharply pointed; bracteoles 1.3–1.5 cm long, coriaceous, reddish, apex reddish, with two fissures 4 mm and 10 mm long, close together, glabrous, acute. Flowers 4–5 cm long; calyx 2.5–2.7 cm long, red to pale red, glabrous, apex trilobed, lobes 2–4 mm long, acuminate; staminal tube 2.5–2.8 cm long, with scattered simple trichomes outside, sparsely seriaceous inside; corolla lobes red to pale red, dorsally sparsely puberulent; dorsal corolla lobe 10–13 mm × 3–4 mm, oblong to oblanceolate, slightly cucullate, apex mucronate; lateral corolla lobes 8–9 mm × 2–3 mm, oblong to oblanceolate, slightly cucullate, apex obtuse; labellum 1.3–1.5 cm × 0.4–0.8 cm, yellowish to pale yellow, reddish at base, ventrally tomentose at the center, erect, lateral lobes embracing the stamen, margin entire, central lobe short, extending up to 7 mm long, apex truncately rounded; stamen 8–12 mm long, filament 3–7 mm × 1–1.5 mm, cream, with scattered simple trichomes outside, glabrous inside; anther 4–6 mm × 3–4 mm, parallel side, densely sericeous, pale yellow to creamy white, anther crest slightly emarginate (up to 1 mm), thecae dehiscent, sparsely puberulous; ovary 5–8 mm × 5–6 mm, brown to pale brown, sericeous, barrel-shaped; epigynous gland 4–6 mm long, entire, only split to apex dorsally, apices blunt, with tufted trichomes; style 3.2–3.5 long, sparsely sericeous; stigma 1–2 mm wide, creamy white, tomentose, ostiole 0.8–1.2 mm wide, oblong, facing forward to upwards; Infructescence 10–11 cm long; pedicel 1–2 mm long; fruit 1–1.7 cm × 1.2–1.5 cm, subglobose to ovoid, reddish brown to red orange, densely covered with shining yellowish trichomes, well protected by persistent bracts, bearing the persistent, stiff, coraiceous calyx; seeds 2–3 mm in diameter, irregularly globose, black, fully embedded in juicy sour–sweet white aril.

Distribution: This Philippine endemic species has only been recorded so far in the island of Mindanao from the provinces of Davao del Sur, Bukidnon and Misamis Oriental ( Fig. 2 ).

Habitat: Growing in primary lower montane forests with humid environment and open to semi-open canopy at elevations between 1200–1500 m asl.

Phenology: Observed flowering and fruiting between January, April, May and June.

Etymology: The specific epithet refers to the densely ciliate leaf margin (Poulsen & Docot, 2018).

Vernacular name & uses: Known as “Tabak-bukalod” by the local people in the type locality or Bagobos; its fruit are eaten by them ( Elmer, 1915).

Conservation status: Following IUCN (2017), we herein propose this species to be treated as ‘Data Deficient’ (DD). Further surveys are needed as there is insufficient information to assess the status of this species with only limited distributional data and no information on population size, trends or threats to the species in the Philippines.

Specimen examined: PHILIPPINES, Mindanao: Bukidnon, Municipality of Pangantucan, Barangay Portulin , Mt. Kalatungan Range Natural Park , elev. 1475 m, 31 January 2016, M.A.K. Naive 103 (USTH incl. pickled flower) ; Bukidnon, Malaybalay City, Barangay Kibalabag , elev. 1484 m, 25 April 2018, M.A.K. Naive 104 (USTH incl. pickled flower) ; Davao del Sur, Marilog, Datu Salumay, Mt. Malambo , elev. 1200 m, 21 July 2009, Acma F. et al. 00006195 (SING) .

Notes: Based on overall morphology, this species shows similarities to Amomum lepicarpum Ridley (1909: 605) recently being synonymised with E. alba ( Blume 1827: 53) A.D. Poulsen (2012: 58) and A. warburgii K.Schumann in Engler (1904: 257). However, E. pubimarginata differs significantly in having these following chracters: coriaceous, sharply pointed, stiff bracts; subglobose to ovoid, densely covered with golden brown hairs fruit. This also means that reinvestigation on the identities of A. warburgii is also needed for it might belong to the genus Etlingera .

A number of characters show greater variation based on the two recent materials than the original given by Elmer. For example, Elmer describes the leafy shoot as 1– 2 m. The specimen collected in Mt. Kalatungan Range Natural Park matches well with Elmer, however, the recent collection from Mt. Kiamo, Bukidnon and Aposkahoy, Misamis Oriental was up to 3 m. There are also some variation observed in the ligule as well as colour and meristics of flower parts which can be explained by the stage of development of the inflorescence, growth conditions and processing techniques. Despite these differences, we are in no doubt that the two recent collections are the same species as Elmer 10546 collected last May 1909 (BISH, BM, BO, F, G, K, L, MO, NY, US).

Figures

FIGURE 1. Etlingera pubimarginata. A. Habit B. Leafy shoot with detail of ligule C. Rhizome and attachmet of inflorescence D Inflorescence in situ E Inflorescence exacavated (scale bar 5 cm) F. Dissected inflorescence (fl: flower (scale 2 cm); b: bract; br: brcateole; ca: calyx; lc: lateral corolla lobes; dc: dorsal corolla lobes; la: labellum; a: anther) G. Detail of fruit (scale 1 cm).A–F, MAK Naive 18-004; G, MAK Naive 18-007. Photographs by M.A.K. Naive.

FIGURE 2. Distribution of Etlingera pubimarginata across Philippine archipelago with its type locality (indicated with star).