White-collared pitcher-plant (Nepenthes albomarginata)

Description

Nepenthes albomarginata /nɪˈpɛnθiːz ˌælboʊˌmɑːrdʒɪˈnɑːtə/ is a tropical pitcher plant native to Borneo, Peninsular Malaysia, and Sumatra. The specific epithet albomarginata, formed from the Latin words albus (white) and marginatus (margin), refers to the white band of trichomes that is characteristic of this species. Nepenthes albomarginata is a climbing plant. The stem may reach lengths of up to 4 metres (13 ft) and is up to 5 millimetres (0.20 in) in diameter. Internodes are cylindrical in cross section and up to 15 centimetres (5.9 in) long. Leaves are coriaceous in texture. The lamina or leaf blade is lanceolate in shape and up to 25 centimetres (9.8 in) long by 2 centimetres (0.79 in) wide. It has an acute apex and its base is gradually attenuate and amplexicaul. The leaves of this species are characteristic in that they completely lack a petiole. Longitudinal veins are indistinct. Tendrils are up to 20 centimetres (7.9 in) long. Rosette and lower pitchers are bulbous in the basal third and cylindrical above. They are relatively small, reaching only 15 centimetres (5.9 in) in height by 4 centimetres (1.6 in) in width. A pair of fringed wings up to 5 millimetres (0.20 in) wide runs down the front of each pitcher. The pitcher mouth is round and rises to form a short neck at the rear. The peristome is cylindrical in cross section, up to 2 millimetres (0.079 in) wide, and bears indistinct teeth. The inner portion of the peristome accounts for around 34% of its total cross-sectional surface length. A dense band of short white trichomes is present directly below the peristome, although these may be missing from pitchers that have caught termites. The glandular region covers the bulbous portion of the pitcher's inner surface. The lid or operculum is suborbicular and lacks appendages. An unbranched spur (≤3 millimetres (0.12 in) long) is inserted near the base of the lid. Upper pitchers are similar to their lower counterparts in most respects. They are cylindrical-infundibular throughout and have a pair of ribs in place of wings. Nepenthes albomarginata has a racemose inflorescence that is usually longer in male plants. The peduncle is up to 25 centimetres (9.8 in) long, while the rachis reaches lengths of up to 40 centimetres (16 in). Partial peduncles are one- or two-flowered, up to 30 millimetres (1.2 in) long, and lack a bract. Sepals are obovate to oblong in shape and up to 4 millimetres (0.16 in) long.[7] A study of 120 pollen samples taken from a herbarium specimen (J.H.Adam 2417, collected in Borneo at an altitude of 0–30 metres (0–98 ft)) found the mean pollen diameter to be 31.8 μm (0.00125 in) (SE = 0.4; CV = 6.2%). Most parts of the plant are covered in a dense indumentum of very short, stellate white hairs. However, the underside of the lamina bears a dense covering of long hairs.