Nepenthes insignis

Species of pitcher plant from New Guinea

Nepenthes insignis /n//ᵻ/'/p//ɛ//n//θ//iː//z// //ɪ//n/'/s//ɪ//ɡ//n//ɪ//s/ is a tropical pitcher plant endemic to New Guinea and surrounding islands. The specific epithet insignis is Latin for "distinguished" or "remarkable".

The first known collection of N. insignis was made by August Adriaan Pulle on November 9, 1912. The specimen, Pulle 277, was collected in southwestern New Guinea at the "[b]order of the Beaufort River" The inner surface of the pitcher is glandular in its lower half. Digestive glands are present at a density of 150 to 1500 per square centimetre. An unbranched filiform spur (≤5 mm long) is inserted near the base of the lid. In the southern part of the Lakes Plain region of New Guinea it has been recorded from elevations of between 115 and 800 m. A smaller form of this species is also found near sea level on the island of Biak. Nepenthes insignis occurs in dense forest and on foothills. Plants usually grow epiphytically in thick layers of moss, especially in trees overhanging rivers. At higher altitudes, the species has also been recorded from sediment bars along rivers. Relative humidity is always high in these habitats; the seeds of one plant which grew near a small waterfall were found to have germinated while still in their capsules. Nepenthes insignis is listed as Least concern on the IUCN Red List.

B. H. Danser suggested that N. insignis is related to N. merrilliana from the Philippines. He placed both species in the Insignes clade, the members of which are characterised by coarse stems, large leaves, sparse indumentums, sessile leaves, and lids without appendages. Nepenthes insignis has also been compared to N. sibuyanensis, another Philippine endemic. It can be distinguished from that species on the basis of a number of morphological features. The former produces two flowered pedicels, whereas those of N. sibuyanensis are one flowered. The pitcher mouth of N. insignis is oblique, compared to almost horizontal in the latter. In addition, the peristome of N. sibuyanensis forms a short neck, while N. insignis lacks a neck completely. Furthermore, N. insignis has shorter peristome teeth than N. sibuyanensis (1 mm versus 5 mm). The pitchers of N. sibuyanensis also differ in shape, being ovate or slightly infundibulate.

A putative hybrid between N. insignis and N. mirabilis was found by members of the 1994 field trip to New Guinea. The plant was growing at an altitude of around 500 m.

In Papua, N. insignis is commonly sympatric with N. ampullaria and N. maxima, and hybrids involving these species may also occur, although none have been recorded to date.