Nepenthes hirtella

Nepenthes hirtella

Synonymy

Nepenthes hirtella Nuanlaong & Suran. in Kew Bull. 77(1): 111. 2022 sec. Nuanlaong & al. 2022
    • Holotype: Thailand, Krabi Province, Khlong Thom Distr., Khao Pra-Bang Khram Wildlife Sanctuary, Mt Khao Shawaplab, alt. 348 – 355 m, 7°50'29.53"S, 99°16'35.45"E, 29 Aug 2019, S. Nuanlaong BKF197453 (BKF)
    • Isotype: Thailand, Krabi Province, Khlong Thom Distr., Khao Pra-Bang Khram Wildlife Sanctuary, Mt Khao Shawaplab, alt. 348 – 355 m, 7°50'29.53"S, 99°16'35.45"E, 29 Aug 2019, S. Nuanlaong BKF197453 (PSU)

Description

Scandent, climbing herb. Root branched, fleshy tubers. Stem terete, 0.8 – 1.2 m long, 0.35 – 0.65 cm diam.; internode 1.5 – 5.5 cm long; upper part of the stem green, lower part of the stem brown. Leaves pseudo-petioles, coriaceous, oblanceolate; 15.8 – 29.5 × 3.5 – 5.4 cm, longitudinally folded to form a V-shape, blade apex acuminate, base attenuate, entire, dilating at the node, projecting along the stem as wing, clasping the stem by three quarters of its circumference, decurrent for 1.7 – 4.3 cm of its length, leaf thickness 0.5 – 1.0 mm, inconspicuous longitudinal nerves 3 – 4 on each side of the midrib in outer third of lamina, inconspicuous lamina reticulated pinnate venation; midrib conspicuous; light green in a rosette when young, green when mature, emerging from a red triangular lateral bud at the base of the midrib near the leaf attachment. Lower pitcher c. 14.0 – 19.7 × 4.4 – 5.9 cm; ovate at the lower part with digestive zone at the inner surface, narrowing at the upper part; hip conspicuous above digestive zone; with two fringed wings, 0.3 – 0.9 cm wide, along the length of the pitcher, 9.0 – 14.3 cm from pitcher mouth to tendril, serrate to double serrate, fringed elements 0.4 – 0.9 cm long, 4 – 11 fringed elements per cm; mouth oblique ovate, concave; peristome cylindrical, entire to repand, revolute when pitcher mature, 0.9 – 1.5 cm wide, inner edge with teeth 0.64 – 1.48 mm long, ridges approximately 0.72 – 1.2 mm apart; lid ovate, 3.9 – 4.9 × 3.3 – 4.9 cm, repand, base cordate 0.5 – 3.0 mm; absent appendage, nectar glands numerous, elliptic 0.18 – 0.28 mm diam. along the midrib, with crateriform gland 0.09 – 0.28 mm diam. dispersed over the lower surface of the lid; spur filiform, 0.1 – 0.9 cm long, with branches; tendril straight, 12.0 – 20.0 cm long, 2.0 – 3.5 mm diam., approximately 10 – 30% longer than pitcher, mostly on the side of the pitcher; light green to yellow or green to red on the lower and green to red or red on the upper part with red blotches on the outside surface, light green present or absent red blotches on inside surface, absent in digestive zone, peristome light green, green to red or red peristome, lid green or green to red. Upper pitcher tubulose, with a conspicuous hip one third from the base or middle of pitcher; 13.0 – 21.0 cm long, 0.9 – 2.8 cm wide; two fringed wings, 1.5 – 8.0 × 0.1 – 0.2 cm, which run down the ventral exterior surface from pitcher mouth to the middle or tendril of the pitcher, serrate or double serrate, fringed elements 0.5 – 2.0 mm long, 4 – 8 per cm; mouth oblique ovate; peristome cylindrical, revolute when pitcher mature, 0.3 – 1.0 cm wide, inner edge with teeth 0.48 – 0.84 mm long, ridges approximately 0.92 – 1.40 mm apart; lid ovate, 2.1 – 4.3 × 2.0 – 4.3 cm, base cordate 0.5 – 1.0 mm, nectar gland similar to lower pitcher; spur filiform, 2.0 – 7.0 mm long; tendril straight, 7.0 – 15.0 cm long, 1.0 – 3.0 mm diam., coiling, shorter than pitcher; green or green to orange outside surface with or without red blotches, green with red blotches over inner surface, absent in digestive zone, peristome light green sometimes red stripes present, lid green. Male inflorescence a raceme, 65.0 – 105.0 cm long, 0.3 – 0.4 cm diam., peduncle 44.0 – 56.0 cm long, rachis 22.5 – 47.0 cm long, flowers 68 – 194, solitary flowers or rarely two-flowered partial peduncle, pedicels 0.5 – 0.8 cm long, bracts present at base of peduncle 0.5 – 3.0 mm long, absent on upper half; tepals 4, elliptic to obovate, 2.0 – 4.0 × 1.0 – 2.0 mm, explanate and not reflexed, cruciferous, densely covered with orbicular to elliptic nectar glands 0.35 – 0.70 mm diam.; androphore 1.0 – 2.0 mm long, anther head globular, 1.0 – 2.0 mm diam., anther basifixed, synandrium, 8 – 12 anther sacs, longitudinal dehiscence; tepals light green when young, green to red when old. Female inflorescence a raceme, 65.0 – 75.0 cm long, 0.30 – 0.35 mm diam., peduncle 40.0 – 58.5 cm long, rachis 12.0 – 20.0 cm long, bracts similar to male inflorescence; flowers 26 – 57, solitary, pedicels 0.2 – 1.0 mm long; tepals 4, elliptic to ovate, 2.0 – 3.0 × 1.0 – 2.0 mm, nectar glands similar to male inflorescence, 0.35 – 0.60 mm diam.; tepals green when young, green to red when old; ovary superior, with four syncarpous carpels, oblong, 3.0 – 5.0 mm long, 2.0 – 2.5 mm diam., stigma head 1.5 – 2.0 mm diam. Infructescence similar to female inflorescence; tepals persistent; four valves, 1.5 – 1.6 cm long with septicidal capsule; seed linear, 4.0 – 8.0 mm long c. 73 – 109 seeds per pod. Indumentum conspicuous, simple brown hairs, pubescent, 0.17 – 0.30 mm long, present on all vegetative parts; fringed elements puberulent.A

Notes

Nepenthes hirtella was first discovered in 2014 – 2015 by a Nepenthes collector/seller and was known as “Seua-Amphon”. Nepenthes hirtella is a member of section Pyrophytae like N. bracteosa and is only found in Mt Khao Shawaplab of Krabi Province, Thailand. Nepenthes hirtella is closely related to N. kerrii but differs in several morphological details, in particular in tendril and indumentum. Nepenthes hirtella is covered by brown hairs throughout, while in N. kerrii the indumentum is confined specifically to the leaf axil and inflorescence. It is distributed on the mainland while N. kerrii is distributed on an island. Moreover, the phylogenetic relationship results show a low similarity index between them

Conservation

Nepenthes hirtella is found only on a single site on the summit of Mt Khao Shawaplab. A decline in the quality of the habitat will lead to the disturbance of the long-term survival of the remaining population. It is easy to get to the habitat, which might put this species at risk of extinction. The calculation of EOO as 0.053 km2, AOO as 8.00 km2 together with the information above suggests that this species is Critically Endangered (CR) [B1a,b (iii) + B2a,b (iii)] (IUCN 2019)A

Distribution (General)

Thailand, Krabi Province

Etymology

From the Latin “hirtella” derived from “hirtellus”: short hairs are present on all the vegetative parts of the plant and rather hairyA

Habitat

On summit areas, in sandy soil, generally growing in open forest, savannas and scrubland, at 348 – 355 m a.s.l.A

Bibliography

A. Nuanlaong, S., Mekanawaku, M. & Suraninpong, P. 2022: Descriptions of two new species of Nepenthes (Nepenthaceae) from Thailand and their phylogenetic analysis based on AFLP technique species confirmation. – Kew Bull. 77(1): 105-120

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
Thailand2019-08-29Nuanlaong, S. BKF197453BKF, PSU
Citation: Thailand, Krabi Province, Khlong Thom Distr., Khao Pra-Bang Khram Wildlife Sanctuary, Mt Khao Shawaplab, alt. 348 – 355 m, 7°50'29.53"S, 99°16'35.45"E, 29 Aug 2019, S. Nuanlaong BKF197453

Specimen summary: BKF
Holotype of Nepenthes hirtella Nuanlaong & Suran.

Specimen summary: PSU
Isotype of Nepenthes hirtella Nuanlaong & Suran.