Nepenthes tentaculata Hook.fil.

Species Nomenclature

Nepenthes tentaculata Hook.fil. is a climbing plant.

Stem Characteristics

Its stem can reach 3 m in length and up to 5 mm in diameter. Internodes are circular to triangular in cross section and grow up to 10 cm long.

Leaf Attachment

This species has sessile leaves.

Leaf Blade Morphology

The leaf blade (lamina) is lanceolate to elliptic, measuring up to 15 cm long and 3 cm wide. The leaf apex is rounded to acute, while the leaf base is amplexicaul, cordate, and encircles the stem.

Leaf Venation

Up to 4 longitudinal veins occur on either side of the midrib, and pinnate veins are irregularly reticulate.

Tendril Size

Tendrils grow up to 15 cm long.

General Pitcher Size

The pitchers of N. tentaculata are generally quite small, rarely exceeding 15 cm in height; exceptional specimens may reach up to 30 cm high by 8 cm wide.

Pitcher Shape

Rosette and lower pitchers are ovoid in the basal third and cylindrical above, while upper pitchers are more cylindrical along their entire length.

Pitcher Wing Morphology

A pair of fringed wings runs down the front of lower pitchers, but these wings are often reduced to ribs in upper pitchers.

Pitcher Mouth Structure

The pitcher mouth is usually ovate, becoming acute at the front and rear, and has a very oblique insertion.

Peristome Morphology

The peristome is roughly cylindrical in cross section, up to 5 mm wide, bears small ribs, and has tiny teeth lining its inner margin. The inner portion of the peristome makes up approximately 57% of its total cross-sectional surface length.

Pitcher Lid Characteristics

The pitcher lid (operculum) is ovate and typically obtuse. Numerous filiform appendages are often present on the upper surface of the lid, concentrated near the edge, but some forms of the species lack these structures entirely.

Inflorescence Type

N. tentaculata has a racemose inflorescence.

Inflorescence Stem Dimensions

The peduncle grows up to 15 cm long and the rachis up to 10 cm long, with female inflorescences generally shorter than male ones.

Pedicel Characteristics

Pedicels are bract-less and reach 10 mm in length.

Sepal Morphology

Sepals are oblong-lanceolate and up to 3 mm long.

Pollen Analysis

A study of 210 pollen samples from a Bornean herbarium specimen (Mjöberg 49, collected at 1,700 m altitude) found a mean pollen diameter of 29.8 μm (standard error = 0.4; coefficient of variation = 9.4%).

Indumentum

All parts of N. tentaculata are glabrous, with no indumentum (hairs) present.

Geographical Distribution

In terms of ecology, N. tentaculata has a wide distribution across Borneo and Sulawesi. It is particularly widespread in Borneo, where it has been recorded from almost every mountain over 1,000 m in elevation.

Altitudinal Range

It usually grows at altitudes between 1,200 and 2,550 m above sea level, but has been found as low as 740 m, and sometimes even 400 m, on coastal mountains such as Mount Silam in Sabah and Mount Santubong in Sarawak.

Habitat Type

The species typically inhabits mossy forest, though it has also been recorded from ridge-top vegetation on mountain summits.

Growth Habit

Unlike many other Nepenthes species, N. tentaculata does not grow as an epiphyte; it always grows terrestrially.

Substrate and Vegetative Growth

Plants often grow in clumps of Sphagnum moss, spreading vegetatively via creeping subterranean stems.

IUCN Red List Status

The conservation status of N. tentaculata is listed as Least Concern on the IUCN Red List, based on a 2018 assessment.

Previous Conservation Assessments

This matches an informal 1997 assessment by Charles Clarke, who also classified the species as Least Concern under IUCN criteria. In 1995, the World Conservation Monitoring Centre classified N. tentaculata as "not threatened".