Nepenthes minima Jebb & Cheek, 2016

Cheek, M. & Jebb, M. H. P., 2016, Nepenthes minima (Nepenthaceae), a new pyrophytic grassland species from Sulawesi, Indonesia, Blumea 61 (3), pp. 181-185 : 182-184

Nepenthes minima Jebb & Cheek , sp. nov. — Fig. 1

Similar to N. maxima Reinw. ex Nees but differs in possessing fleshy underground perennating tuberous rootstocks (not without tubers), flowers one per partial-peduncle (not two), bracts absent from partial-peduncles (not present). — Type: Ramadhanil et al. 280 (holotype K; isotypes BO not seen, CEB not seen), Indonesia, Sulawesi, Tengah Tamadue, Napu, Lore Utara , Poso , fl. 15 May 2001 .

Etymology. Minima meaning ‘small’, in contradistinction to ‘maxima’ the epithet of the species to which it is most similar, yet much smaller in all its parts.

Pyrophytic dioecious, terrestrial subshrub 0.3–0.6 m tall. Stems annual, erect, arising from a fleshy-leathery, vertical underground rootstock c. 8 by 2 cm, the upper part densely covered in the carbonised bases of stems resulting from fires in previous dry seasons. Rosette and c limbing stems unknown and probably not produced. Short stems terete or slightly rounded-angular 3–5 mm diam, internodes (3.2–)4.5–5.2(–6) cm long, indumentum a mixture of dendritic and stellate hairs 0.2–0.7 mm long, dull white to orange-grey, 50–80 % cover at stem apex, decreasing to 10 % cover at the fourth internode from the apex. Leaves petiolate, blades elliptic-oblong, (4.8–)5–9(–12.5) by (1.3–)1.8–2(–3.5) cm, apex acute, tendrils apical 7–10 cm long, base cuneate; longitudinal nerves 3 on each side of the midrib in the outer third of the blade, all arising from the proximal two-thirds of the blade midrib; pennate nerves irregular, patent; indumentum inconspicuous, dull white simple (or inconspicu- ously branched), and 2–4-armed sessile hairs 0.15–0.3 mm long, mixed with sessile depressed-globose glands 0.05 mm diam, indumentum covering c. 10 % of both upper and lower surface of young leaves, glabrescent. Petiole canaliculate, (2–) 3–5 cm long, 0.2 cm wide, 0.2 cm high, indumentum as the blade, but slightly denser, and longer (to 0.6 mm long). Lower pitcher not recorded. Intermediate pitchers infrequently produced in mature plants, narrowly infundibulate-cylindrical c. 9 cm long, c. 2 cm wide below peristome, c. 1.5 cm diam half way between base and apex, with two fringed wings running from the peristome, 9/10 the length of the way to the base of the pitchers; fringed wings 2 mm wide, fringe-elements 1–3 mm long, 2–3 mm apart; outer surface of pitcher with similar indumentum to that of the upper pitchers (see below); mouth narrowly ovate, concave, arising abruptly at the rear into a column, oblique, inner surface not recorded; peristome rounded, 3–4.5 mm wide, ribs 0.4 mm apart, 0.1 mm high, separated by c. 12 well-marked parallel ridges, outer edge entire, recurved, inner edge recurved and with teeth inconspicuous, column triangular, c. 18 by 7 mm at the base; lid narrowly ovate, c. 25 by 16 mm, apex acute, base rounded, upper and lower surface similar to the upper pitchers (see below), apical appendage c. 4 mm long; spur simple, 6 mm long, indumentum of short black hairs. Upper pitchers (tendrils coiled, dorsal to pitcher), green, slightly curved along main axis, narrowly infundibuliform, rarely cylindrical (5–)6–10.5(–12) by 1.2–1.5(–2.05) cm, nar- rowing to 1–1.2 cm wide halfway between base and peristome, the ‘hip’ not developed, wings absent; indumentum of the outer surface 10–30 % covered in three types of indumentum, large 3–5-branched, dendritic hairs 0.2–0.5(–0.7) mm long, (2–)5(–7) per mm 2; small 4-armed stellate hairs (rarely bifid or trifid) 0.1 mm diam, 1–6 per mm 2; sessile depressed-globose glands 0.05 mm diam, 4–7 per mm 2; mouth narrowly ovate, flat and oblique in the frontal half, slightly concave in the rear part, rising to form a weakly defined column, inner surface at mouth with upper exposed half waxy, the lower half glandular, glossy; peristome flattened-cylindric in transverse section, 3–4.5 mm wide, ridges 0.25–0.5 mm apart, developed as acute low ridges 0.2–0.25 mm high, outer edge revolute, entire, inner edge with teeth 0.2 mm long and broad, visible only at the base of the column, the inner edge otherwise folded inwards; lid narrowly ovate, 1.8–2.8 by 0.8–1.2 mm, apex acutely rounded, base truncate and shortly and abruptly cordate, upper surface with indumentum as the outer pitcher surface, lower surface with both a basal and apical appendage arising from the midline ridge, basal appendage inconspicuous, laterally flattened, inequilaterally triangular, c. 1.5 mm long, c. 0.8 mm high with nectar glands sparse, apical appendage filiform-cylindrical (1–)2.8–4 by 0.25 mm, arising 0.4–0.5 mm before the lid apex, with 3–7 nectar glands concentrated at the apex, nectar glands absent from the midline of the lid (except the midline in the distal part often with 1– 2 longitudinally elliptic nectar glands up to 0.7 by 0.3 mm, Fig. 1k) and from the marginal 0.2–0.3 mm numerous, mostly ± monomorphic and uniformly dense, c. 12 per mm 2, orbicular, 0.15–0.25(–0.3) mm diam, bordered, the borders covering 30–50 % of the surface area, the peripheral nectar glands at the smaller end of the size range, and sparser, sessile depressed-globose or 8-rayed glands scattered over the entire surface, c. 0.05 mm diam, marginal 0.1–0.2 mm of lid with dense bushy hairs 0.05–0.1 mm long; spur filiform, simple, inserted 3–4 mm below the lid, 6 mm long, indumentum of short patent, black hairs with 100 % cover. Female inflorescence (male unknown) erect 21.2–33 by 3 cm, indumentum a mixture of randomly orientated appressed white hairs 0.1–0.4 mm long and red depressed-globose glands 0.06 mm diam extending from peduncle to lower surface of tepals, peduncle 7.2–16 cm long, by 0.2 cm diam, glabrescent; rhachis 13–17 cm long, 50–80 % covered in indumentum; partial-peduncles 20–27, each 1-flowered, bracts absent, pedicels 0.3–0.6 cm long, about 50 % covered in indumentum. Female flowers with tepals (4–)5–6, narrowly oblong-elliptic 2.3–2.6 by 0.8–0.9 mm, apex rounded, upper surface with 15– 20 longitudinally elliptic nectar glands, lower surface about 20 % covered in hairs; ovary bottle-shaped, 3.5 by 1.1 mm, 100 % covered in white appressed hairs 0.2–0.3 mm long; stigmas four, bifurcate, basally united, forming a head 1 mm diam, drying glossy black. Fruit valves 4, 9.5 by 1.5 mm, with dense appressed hairs. Seeds filiform-fusiform, 4.4 by 0.11 mm, pale yellow, central portion smooth.

Distribution & Ecology — Indonesia, Sulawesi Tengah. Open grassland with Imperata , Arundina and Spathoglottis species; substrate grey-yellow clay; altitude 1000–1700 m. Unlike the majority of species in the genus this species flowers preco- ciously in cultivation both in size and age, and this may well be an adaptation to frequent fires in its native habitat.

Vernacular name — Kantong semar (Ramadhanil et al. 280).

Additional specimens. INDONESIA, Sulawesi, Sulteng Prov., Lake Poso area, 1000 m, seed collected in 1985 by John Turnbull , cultivated at Royal Botanic Gardens , Kew in the Tropical Nursery , specimen made Jan. 2016 Cheek 18271 ( K) .

Conservation — The records of Turnbull (preserved as Cheek 18271) and of Ramadhanil et al. 280 give two locations in close proximity for N. minima , but give no indication of the numbers of individuals seen. McPherson’s excellent notes (2009, cited above) on this species imply that he saw several plants in more than one place since he twice remarks that he observed ‘populations’. He also refers to the populations reported to him by Ch’ien Lee, another notable observer of Nepenthes . Since McPherson gives an altitudinal range of 1400–1700 m, above the range in which fall the specimens cited in this paper, it is reasonable to conclude that he and Ch’ien Lee each saw plants at two to four locations giving a total probable number of locations of between six and ten. Threats to the species do not appear to be high, but in several grassland plains, new areas of settlement and cultivation seem to have appeared in recent years which will pose a danger if the species is not protected. The known sites for N. minima do not fall in a protected area. Nepenthes minima is here assessed as Vulnerable, VU B2a, b(iii) under the criteria of IUCN (2012), since ten or less locations are known with an Area of Occupancy of 40 km 2 at most, using IUCN preferred 2 by 2 km gridcells.

Note — Nepenthes minima appears to have high potential as an indoor plant given its small size, rapid growth, and ability to withstand both waterlogging and drying-out. It has colourful, elegantly-shaped pitchers which are freely produced. All these features lend the species to employment as an ornamental windowsill plant in temperate zones of the world, possibly in terraria or other enclosed cases if humidity is low.