Nepenthes bracteosa
Synonymy
Nepenthes bracteosa in Kew Bull. 77(1): 109. 2022 [From the Latin “bracteosa” derived from “bracteosus”: bracts are present on the pedicels of all flowers of both male and female inflorescencesB]. sec. Nuanlaong & al. 2022
- Holotype: Thung Song Distr., Yong Waterfall National Park, Mt Khao Wang Hip, alt. 710 – 760 m, 8°16'6.8"S, 99°40'11.99"E, 29 Aug 2019, S. Nuanlaong BKF197454 (BKF)
- Isotype: Thung Song Distr., Yong Waterfall National Park, Mt Khao Wang Hip, alt. 710 – 760 m, 8°16'6.8"S, 99°40'11.99"E, 29 Aug 2019, S. Nuanlaong BKF197454 (PSU)
Description
Scandent, glossy climbing herb. Root branched, fleshy tubers. Stem terete, 0.5 – 1.0 m long, 0.3 – 0.5 cm diam.; internodes 1.3 – 2.7 cm long; axillary bud present in 2 – 3 axils in the upper part of the plant when flowering; upper part green to red and lower part brown. Leaves pseudo-petiolate, coriaceous, linear to lanceolate; 14.0 – 24.0 × 2.0 – 3.9 cm, longitudinally folded to form a V-shape; blade apex acute to acuminate, base attenuate, entire, dilating at the node, projecting along the stem as a wing, clasping the stem by three-quarters of its circumference, decurrent for 0.8 – 2.8 cm of its length, obscure longitudinal nerves on each side of the midrib at the edge of lamina, as leaves are thickened, inconspicuous reticulated pinnate venation; midrib conspicuous; tendrils straight, terete, 15.0 – 26.0 cm long in lower pitchers, upper pitchers 10.0 – 15.0 cm long, coiling; glossy light green when young, green when mature, emerging from an orange–amber, triangular lateral bud at the base of the midrib near the leaf attachment. Lower pitcher c. 10.5 – 19.0 × 3.4 – 5.6 cm; ovate in the lower part with digestive glands on the inner surface, cylindrical to narrowing in the upper part; conspicuous midsection hip; with two fringed wings, 0.6 – 1.3 cm wide, along the length of the pitcher, 6.5 – 12.0 cm from pitcher mouth to tendril, fringed elements 0.3 – 1.2 cm long, 4 – 8 fringed elements per cm; mouth ovate, concave; peristome cylindrical, undulate, revolute when pitcher mature, 0.7 – 1.9 cm wide, inner edge with teeth 0.6 – 1.7 mm long, ridges approximately 0.4 – 0.5 mm apart; lid broadly ovate to round, 2.8 – 4.4 × 3.3 – 5.0 cm, larger than mouth, sometimes vaulted or bent towards the mouth, base cordate 1.0 – 4.0 mm, apex occasionally emarginate, indurate, like appendage on the lower surface, nectar glands numerous, elliptic, 0.16 – 0.26 mm diam. along the midrib, and with crateriform glands 0.12 – 0.18 mm diam. dispersed over the lower surface of the lid; spur filiform, 0.2 – 0.8 cm long, with branches; green to red on lower part and red on upper part with red speckled outside, light green to red with red blotches over the inside, absent in digestive zone, peristome green to dark red, lid green to red. Upper pitcher tubulose, with a conspicuous hip one third from the base; 10.0 – 19.0 cm long, 2.0 – 3.4 cm wide; two fringed wings, 0.1 – 0.3 cm wide, along the length of the pitcher, 9.0 – 16.0 cm long, fringe elements 0.3 – 0.7 cm long, 3 – 6 per cm; pitcher mouth similar to lower pitcher; peristome cylindrical, revolute when pitcher mature, 0.4 – 1.0 cm wide, inner edge with teeth 0.29 – 0.43 mm long, ridges approximately 0.4 – 0.5 mm apart; lid ovate to round, 2.1 – 3.4 × 2.1 – 4.4 cm, base cordate 1.0 – 3.0 mm, apex emarginate similar to lower pitcher, elliptic nectar gland along the midrib on the lower surface of lid, numerous near base, 0.1 – 0.2 mm diam. and with crateriform glands 0.05 – 0.1 mm diam. scattered over the lower surface of the lid; spur filiform, 3.0 – 7.0 mm long, with branches; pitchers green or green to red, sometimes red-speckled outside, light green with red blotches over the inner surface, absent in digestive zone, peristome and lid light green. Male inflorescence a raceme, 70.0 – 85.0 cm long, peduncle 47.0 – 55.0 cm long, 0.2 – 0.5 cm diam., rachis 13.0 – 32.0 cm long, flowers 84 – 135, solitary, pedicels 3.0 – 5.0 mm long, with bracts at the base or lower half of pedicel 0.8 – 1.0 mm long, present on all flowers; tepals 4, ovate, apex obtuse, 4.0 – 5.0 × 3.0 – 4.0 mm, reflexed in mature flower, densely covered with orbicular to elliptic nectar glands 0.20 – 0.36 mm diam.; androphore 2.0 – 2.5 mm long, anther head globular 2.1 – 2.5 mm diam., anther basifixed, synandrium, 8 – 13 anther sacs, longitudinal dehiscence; tepals light green when young, red when old. Female inflorescence a raceme, 50.0 – 86.0 cm long, 0.2 – 0.4 cm diam., peduncle 42.0 – 74.0 cm long, rachis 9.0 – 16.0 cm long, flowers 20 – 42, solitary, pedicels 0.5 – 1.7 cm long, with bracts 1.0 – 1.5 mm long, inserted at one third of pedicel height, conspicuous on upper part of rachis, present on all flowers; tepals 4, ovate to elliptic, 3.8 – 4.0 × 2.0 – 2.2 mm, nectar glands similar to male inflorescence, 0.20 – 0.28 mm diam., green when young, green to brown when old;. ovary superior, with four syncarpous carpels, oblong, 5.0 – 6.0 mm long, 2.3 – 2.5 mm diam., stigma head 1.0 – 1.5 mm diam. Infructescence similar to female inflorescence; tepals persistent; four valves, 1.0 – 1.2 cm long with septicidal capsule; seeds linear, 6.0 – 6.6 mm long c. 98 – 125 seeds per pod. Indumentum conspicuous, inflorescence and outer pitcher pubescent with simple brown hairs; tendril with simple and branched hairs; wing fringed elements puberulent, with branched brown hairs; leaf midrib puberulent with inconspicuous, simple, dark green hairs; absent on stem, leaf axils, lamina, leaf margin, and shootA
Notes
Nepenthes bracteosa was first discovered from a photograph taken by a tourist. It is only found at a single location in Southern Thailand. It belongs to section Pyrophytae on account of sharing several characteristics such as long racemose inflorescence, climbing stem, flower from the rosette stage, tuberous rootstocks, and pyrophytic habitat. Nepenthes bracteosa is similar to N. krabiensis, with which it shares being glossy, climbing, its leaf shape and an inconspicuous indumentum, but differs in many other morphological characteristics. However, the results of the phylogenetic relationship revealed a similarity coefficient as 0.65 between N. bacteosa and N. krabiensis, which is also the highest of all species pairs recordedA
Conservation
This species is distributed at a single site on the summit of Mt Khao Wang Hip. A decline in the quality of the habitat will lead to the disturbance of the long-term survival of the remaining population and may thus increase the extinction risk of this species. The calculation of EOO as 0.034 km2 and AOO as 4.00 km2 together with the information above suggests that this species is Critically Endangered (CR) [B1a,b (iii) + B2a,b (iii)] (IUCN 2019).A
Habitat
On summit areas, in sandy soil, generally growing in open forest and limestone rock crevices, 710 – 760 m a.s.l.A
Specimens
| Country | Date | Collector + collecting number | Herbaria | Type | Scan | Derivatives | |
|---|---|---|---|---|---|---|---|
| 2019-08-29 | Nuanlaong, S. BKF197454 | BKF, PSU |  | ||||
| Citation: Thung Song Distr., Yong Waterfall National Park, Mt Khao Wang Hip, alt. 710 – 760 m, 8°16'6.8"S, 99°40'11.99"E, 29 Aug 2019, S. Nuanlaong BKF197454 Specimen summary: BKF Holotype of Nepenthes bracteosa Nuanlaong, Mekanawaku, M. & Suran. Specimen summary: PSU Isotype of Nepenthes bracteosa Nuanlaong, Mekanawaku, M. & Suran. | |||||||