Nepenthes Longifolia - Description

Description

Nepenthes longifolia is a strong climber; the stem often grows to 10 m and can attain a length of up to 12 m. It is up to 9 mm in diameter. Internodes are sub-cylindrical in cross section and up to 12 cm long.

Leaves are coriaceous in texture. The lamina is lanceolate to lanceolate-spathulate or lanceolate-obovate in shape and up to 55 cm long and 9 cm wide. It has an emarginate apex. The lamina is gradually attenuate into a short petiole (≤7 cm). The petiole is decurrent into a pair of wings (≤2 mm wide) that extend over almost the whole length of the internode. Three to eight longitudinal veins are present on either side of the midrib. Pinnate veins are numerous but indistinct. Tendrils are usually shorter or as long as the lamina, although they may be as long as 110 cm.

Rosette and lower pitchers are infrequently produced and are borne on very long tendrils. They are ventricose or narrowly ovoid in the lower part and cylindrical above. They grow up to 20 cm high and 5 cm wide. A pair of fringed wings (≤5 mm wide) runs down the front of the pitcher. The fringe elements are up 6 mm long and are spaced 1 to 3 mm apart. The pitcher mouth has an oblique insertion and is acuminate towards the lid. The peristome is flattened, up to 6 mm wide, and has a distinct raised section at the front, often with one or two notches. It is broadly cylindrical in cross section and bears a series of ribs spaced 0.2 mm apart. The glandular region covers the ventricose portion of the inner surface. Overarched glands are present at a concentration of around 500 per square centimetre. The pitcher lid or operculum is orbicular or ovate, up to 3 cm in diameter, and lacks appendages. A number of large round to ovate glands are concentrated near the midrib on the lower surface of the lid. An unbranched spur (≤15 mm long) is inserted near the base of the lid.

Upper pitchers arise gradually from the end of the tendril, forming a curve up to 4 cm wide. They are narrowly infundibular in the lowermost parts, slightly ovoid up to the hip, and cylindrical or tubulose above. Upper pitchers are produced on shorter tendrils, but are larger than their lower counterparts, growing to 25 cm in height and 4 cm in width. They have a pair of prominent ribs in place of wings, sometimes bearing fringe elements near the peristome. As in lower pitchers, the mouth is oblique, elevated, and acuminate towards the lid. The flattened peristome is up to 6 mm wide. It has a raised section at the front and is characteristically crumpled into 3 prominent folds. The glandular region covers the infundibulate part of the inner surface, with around 500 glands per square centimetre. The lid and spur are similar to those of lower pitchers.

Nepenthes longifolia has a racemose inflorescence. Male and female inflorescences have the same structure. The peduncle is up to 25 cm long and 3 mm wide. The rachis is also up to 25 cm long. Partial peduncles are one- or two-flowered, up to 15 mm long, and may or may not be bracteolate. Sepals are ovate and up to 5 mm long. Stamens are approximately 5 mm long including the anthers. Seed capsules are up to 3 cm long.

Most parts of the plant bear a short, sparse indumentum of simple and stellate hairs. However, many of these hairs are caducous and so mature plants appear mostly glabrous. The margins of the lamina are densely lined with short reddish-brown hairs.

The stem and leaves are green, the latter sometimes having a reddish lower surface. Leaves of rosette plants often have a red midrib. Lower pitchers are generally brownish-red with a green to reddish-green peristome. The inner surface of the pitcher is usually pale green and the lid is red. Upper pitchers are characteristically light green throughout.