Seringia botak Cheek, 2018

Seringia botak Cheek View in CoL , sp. nov. — Fig. 1 View Fig , 2 View Fig

Differs from all other known species of Seringia J.Gay in having uniformly 1-flowered inflorescences (not 2–many-flowered). Differing from those species with appressed, fan-shaped stellate hairs on the adaxial surface of the calyx ( S. adenolasia F.Muell. , S. corollata Steetz and S. hookeriana (Walp.) F.Muell. ) in the dense long-stalked glandular hairs at margins of calyx and leaf-blade, and in the large ( 2 mm diam) brown, dense stellate hairs on the stems. — Type: Cheek 18779 (holo MAN; iso BO, K, L), New Guinea, Indonesia, West Papua Province, SE of Manokwari,Manokwari Regency,Ransiki District, Gunung Botak, S1°38'44.69" E134°05'27.54", fl., fr. 25 June 2017.

Etymology. Named as a noun in apposition for the type locality, Gunung Botak (meaning Bald Mountain) where the authors discovered this species and which is a possible future Important Plant Area ( Darbyshire et al. 2017).

Thicket-forming shrub, probably spreading by rhizomatous growth, 1.5–2 m tall. Stems stiff, branching only sparingly, and only at 1 m or more above the ground. Stems erect, terete 1–1.5 cm wide at base, with side-branches ascending at c. 45° from the vertical, arising at intervals of 10–30 cm from the principal axis, internodes 1.2–1.8(–2) cm long, 0.15–0.2 mm wide; stem apices held horizontally or nodding, indumentum dense bright sessile stellate orange-brown tomentose, hairs 10–40-armed, 2 mm long, arms stiff, erect, copper-coloured, concealing sparse stalked translucent capitate glandular hairs 0.25–0.3 mm long, mixed with white erect armed stellate hairs 0.3–0.5 mm long. Stipules early caducous, very narrowly triangular at base, apex filiform, 4–5 by 0.5 mm wide at base, 0.25 mm wide at apex membranous, pink-brown, indumentum as stem, but shorter and sparser. Leaves alternate, distinctly distichous, in two ranks on each side of the horizontal or ascending stems, declinate, held 30–80° from the horizontal. Petiole terete c. 4 mm long, indumentum as stem. Blade discolorous, the upper surface dark green, rugose, lower surface bright white tomentose, narrowly oblong-lanceolate, 5–9 by 0.9–1.8 cm, base rounded, abruptly and slightly cordate, sinus 1 by 1 mm; margin flat, entire; apex acute, without apiculus. Adaxial surface with primary to tertiary nerves deeply impressed, 20–30 % covered in white stellate hairs of 2 size classes: 1) sparse 8-armed hairs 0.5 mm diam; 2) minute 3–5-armed erect hairs 0.1 mm diam, glandular hairs absent; margins densely glandular hairy, hairs multicellular, 0.25 mm long, translucent, head black. Abaxial surface with secondary nerves 8 or 9 on each side of the midrib, barely detectable, nerves with sparsely scattered large stellate hairs, white with tan centres, 12–14 stiff arms, spreading c. 1.5 mm diam, mixed with black-headed glandular hairs, the rest of the surface between the nerves completely covered in bright white arachnoid stellate hairs 0.25–0.3 mm diam, 10–15-armed, the arms fine, sinuous, entangling with each other; glandular hairs absent or extremely inconspicuous. Inflorescence 1-flowered, pendulous, held beneath the horizontal young stems, leaf-opposed, often two inflorescences per stem at successive nodes, opening in succession; 22–25 mm long, indumentum a mixture of four hair types: 1) large stellate hairs, c. 10-armed, arms robust erect 1.5 mm long, moderately dense; 2) glandular hairs about as long as previous, heads pale brown or black, stem translucent, with 6–10 red transverse walls; 3) small, stellate, white hairs, arms fine, sinuous, 0.25 mm tall; 4) short glandular hairs 0.1–0.25 mm long, heads white. Bracts (2 or) 3, caducous, pink-brown or red, inserted close to each other, in an uneven whorl, narrowly lanceolate-oblong, membranous 6–7(–8) by 1–1.5(–2) mm, apex acute, base rounded, indumentum as inflorescence axis; bracts inserted: 1) 6–8 mm from base; 2) c. 15–17 mm from base; 3) 17.5–19 mm from base. Calyx spreading, purple, 7–8 mm long; tube 1/8–1/9 of total calyx length; lobes ovate, longer than wide c. 7.5 by 3.5–4 mm, margin entire, apex acute. Abaxial surface with moderately dense, clavate, white-headed glandular stalked hairs, 0.1–0.25 mm long, over-topped and concealed by 80 % cover of white stellate hairs with c. 12 fine erect arms. Adaxial surface with midrib raised in distal quarter, surface entirely lacking glandular hairs (or if present highly inconspicuous), midline of lobes with appressed silvery fan-like stellate hair 0.5–0.75 by 0.1 mm, 6- or 7-armed, the arms all robust, parallel and touching, directed towards lobe apex, covering 60 % of the surface; marginal thirds of calyx lobes with stellate hairs with fine, sinuous, entangled arms c. 0.1 mm long, covering c. 50 % of the surface, calyx tube proximal to androecium glabrous in a ring 0.75–1 mm wide; margin of a calyx entire, densely glandular hairy, hairs 0.3–0.5 mm long, translucent, multicellular, heads black, elliptic, c. 0.1 mm long. Petals 5, patent, canaliculate trullate, 0.75–1 by 0.3 mm, the apex triangular, yellow, the two lateral triangles dark red, slightly inflexed. Androecium and gynoecium erect (in the pendulous flower). Staminal tube absent or 0.2 mm long. Sta- minodes absent, rarely present, then ligulate, 1.25 by 0.2 mm. Filaments yellow, red at apex, ligulate, 1.75–2 by 0.75 mm, outer surface convex, minutely densely puberulent with simple hairs 0.05 mm long. Anthers yellow, glabrous, 2-celled, oblong, 1–1.1 by 0.5 mm touching (cohering?) laterally, pollen yellow. Gynoecium ovary 5 free carpels, outer surface densely covered in translucent, erect to stellate hairs c. 1 mm long, the arms exserted beyond the staminal filaments by 0.75–1 mm; ovules 6 per carpel; styles as many as carpels, 2–2.5 mm long, glabrous, appressed together and appearing as one when live, not twisted, stigmas truncate, coherent. Fruit pendulous during development, the inflorescence axis slightly accrescent, 27–29 mm long. At maturity infructescence erect, fruit and calyx held erect, above the stems, dull brown, matt; sepals becoming concave in fruit, dull dark purple accrescent, doubling in dimensions, 14–15 by 8.5–9 mm, glossy with a raised re- ticulum of nerves, papery, enfolding the developing green fruit. Fruit subglobose, 11 by 15 mm; outer surface with numerous sessile white, stellate hairs with 10–14 erect arms 1 mm long, glandular hairs absent. Carpel wings developed along lines of dehiscence, 3–4 mm wide. Carpels free from each other apart from the basal 1/4–1/3, carpel wall 0.25–3 mm thick, woody, each 2- or 3-seeded. Setae numerous, densest along the wing apices, 1.75 by 0.25 mm, also on the sides of the wings and, more sparsely, between the wings. Seeds glossy black, straight, ellipsoid, 3.75 by 2 by 1.75 mm, aril bright white, dome-like over micropyle, 1 by 1 mm; chalaza horseshoe-shaped, epidermal cells longitudinal, seed-coat cartilaginous. Embryo green, c. 2 mm long, cotyledons equal, orbicular, flat, 0.9–1 mm diam, radicle cylindric, c. 1.1 mm long, 0.25 mm diam. Seedlings, juvenile leaves and chromosome number unknown.

Phenology — Flowering: June, and probably some months previously and subsequently (fruits seen at all stages of development, and flower buds seen).

Distribution & Ecology — Broken mineral substrate in naturally open, areas (presumed nickeliferous) in an otherwise lowland evergreen forest area (Botak) or “lowland savannah … growing under Melaleuca … substrate unconsolidated qua- ternary alluvial and littoral deposits … rainfall 3000 mm p.a. ” (Bomberai: Anon 2005). Endemic to Indonesian New Guinea, near sea-level, at coast.

Additional specimens. INDONESIA, New Guinea , Takeuchi , Sambas , Maturbongs 15719 (BO not seen, CANB not seen,K not seen, L4152226 , MAN not seen), Bomberai Peninsula, Tangguh Survey area E of BP Saengga base camp, near S02°27'26" E133°06'38", fl. 13 Feb. 2002 GoogleMaps ; Kanehira & Hatusima 12963, 13205 (FU not seen: see note below),Waren, 60 km S of Manokwari , Mar. 1940 .

Conservation — Seringia botak has so far only been recorded at two locations. The Bomberai site is part of the licence area of the Tangguh Liquified Natural Gas (LNG) industrial complex owned by BP. Here the species was discovered during a two week botanical survey that was part of an Environmental Impact Assessment ( Anon 2005). In this study the species was (as Keraudrenia corollata ) one of 18 ‘Noteworthy Flora Species’ listed ( Anon 2005: 64, table A5.1) which included five to eight species identified as new to science, among which two of the species later described were: Glochidion daviesii W.N.Takeuchi ( Euphorbiaceae ) and Scaevola burnettii W.N.Takeuchi ( Goodeniaceae ) ( Takeuchi 2003). The last species was indicated as occurring in savannah, as was the Seringia . 123 ha of this habitat were due to be cleared as part of a total of 642 ha lost to the industrial installation ( Anon 2005). However, Anon (2005: 31) concludes that “All habitats and vegetation types are widespread in the region, and no species of flora or fauna are confined to the project property. Accordingly, the Project will not have significant impacts on the biodiversity of the region”. Concerning the savannah, areas are stated to occur to the west, outside the project area (confirmed by viewing on Google Earth 7 March 2018), while the predominant vegetation is lowland rainforest. While the savannah in this area was described as species-poor, and not flagged up as a conservation priority, Takeuchi (2006) later stated that the presence of endemic species such as the Scaevola suggested that the Melaleuca savannah in this area was not anthropogenic but natural. Seringia botak appears to be an additional endemic element of this savannah formation, the extent, composition and conservation value of which are unknown.

Clearly, at the Bomberai site the species may already have been lost subsequent to the Impact study due to the clearance of savannah for the construction of the industrial area or for the accommodation area nearby. The label data suggests that only a single plant or patch may have been seen by Takeuchi. It is not known whether the substrate at this site is nickeliferous or not. At the type location, Gunung Botak, Seringia botak was observed by the authors at a single site, where it occupied an area of 6–8 m 2. It very likely occupies a second site close by also ( Merrill & Perry 1949, see below). Owing to the distinctive dense growth and showy purple flowers this is a conspicuous species that is not easy to overlook. Yet, Indonesian New Guinea remains incompletely surveyed for plants and this species may well have other sites in naturally open savannah or grassland areas .

However, using the precautionary principle and the evidence available, as recommended by IUCN (2012), we here assess Seringia botak as Endangered B1+2ab(iii) since two locations are known, with a total of three sites being probable. Therefore, the area of occupancy is 12 km 2 (using the preferred IUCN cell-size of 4 km 2), while the extent of occurrence is below the criterion B threshold. Threats are evident at both locations: the Tangguh-Bomberai location is in the licence area of an expanding industrial complex (see above) while the Gunung Botak location is threatened by road-widening work that was in progress during our visit. The plants seen there were all close to the road, and at the foot of a steep cliff. Part of Gunung Botak is also threatened by quarrying for materials for cement manufacture ( Makuba 2015). There is also a risk that the area might be open-cast mined since the rock is considered to contain nickel (Utteridge pers. comm. to Cheek 2017). Currently, Gunung Botak is unprotected, but it may be worth recognising it as an Important Plant Area if it fulfils the revised criteria of Darbyshire et al. (2017). Ex situ conservation measures are in place for S. botak since several hundred seeds are now stored in the Indonesian Seed Bank.