Nepenthes izumiae

Nepenthes izumiae is a highland pitcher plant endemic to Sumatra, known only from two peaks in the Barisan Mountains north of Bukittinggi, West Sumatra. It grows mostly as an epiphyte in mossy montane forest at 1,700 to 1,900 m and has very dark, often purplish-black pitchers.

Nepenthes izumiae is a climbing plant growing up to 8 m tall, with a green to reddish stem. Its leaves are linear, lanceolate or spoon-shaped, up to 28 cm long and 8 cm wide, sometimes with a frilled edge, and the tendril often joins the underside of the leaf before its tip.

Lower pitchers are egg-shaped at the base and cylindrical above, up to 30 cm (12 in) tall and 6 cm wide, with fringed wings. The peristome widens to up to 3 cm at the sides and back, and its ribs end in teeth up to 8 mm long. A triangular or hook-shaped crest is often present under the lid. Lower pitchers are typically purplish black, though their hairs can give an orange or brown sheen; the peristome is purple, black or dark brown, sometimes with paler teeth. Upper pitchers are smaller, up to 20 cm tall, narrowly funnel-shaped below and cylindrical above, and usually lighter in colour.

It appears most closely related to the Sumatran endemics N. lingulata and N. singalana. It lacks the long appendage of N. lingulata and differs from N. singalana in its lid crest, broader leaves and mainly epiphytic habit. Natural hybrids with N. dubia and N. jacquelineae are known.

Sebaka sa Native: Barisan Mountains north of Bukittinggi, West Sumatra, Indonesia (endemic)

Libaka tsa Tlelaemete: Tropical highland (1,700-1,900 m)

Nepenthes izumiae grows in upper montane mossy forest at 1,700 to 1,900 m, where conditions are moist and sunlight is diffused. It is most often epiphytic on moss-covered branches, but also grows on the ground over a layer of moss; the original description calls it strictly epiphytic. At one site the vegetation is dominated by Dicranopteris and Dipteris ferns. It grows alongside N. dubia and N. gymnamphora. To protect it, the exact locality was not published.

Boholo bo Holileng: Climbs to 8 m; lower pitchers up to 30 cm (12 in), upper up to 20 cm

Sekhahla sa Khōlo: Moderate

Mofuta oa Sefi: Pitfall Trap

The pitchers are pitfall traps. In upper pitchers the glandular, digestive region covers the lower part of the inner surface below the hip. Lower pitchers have a toothed peristome and a crest under the lid, while upper pitchers have a narrower peristome with much smaller teeth.

It is named after Izumi Davis, wife of Troy Davis, one of its describers.
Before it was named it was known as 'Nepenthes species B'.
Flowering-size plants were already in cultivation, labelled N. singalana from Mount Talakmau, before it was described.
Stewart McPherson considers it at significant risk from poaching, and its only known sites are outside national parks.
The IUCN Red List assessed it as Least Concern in 2018 (Clarke, assessment T48973443A143970314).

Charles Clarke first mentioned the plant in his 2001 monograph Nepenthes of Sumatra and Peninsular Malaysia as 'Nepenthes species B', unsure whether it was an unusual variety of N. singalana. Troy Davis, Charles Clarke and Rusjdi Tamin formally described it in the journal Blumea in 2003. The holotype was collected in the Barisan Mountains north of Bukittinggi on 13 July 2000 and is held at the herbarium of Andalas University in Padang. Stewart McPherson treated it in detail in Pitcher Plants of the Old World (2009).

1. Nepenthes izumiae, Wikipedia
2. Nepenthes izumiae, Caryophyllales Network: Nepenthaceae (after Clarke, Davis & Tamin 2003, Blumea 48: 179-182)
3. Nepenthes: species of Sumatra, The Carnivorous Plant FAQ (Barry Rice)
4. Nepenthes: basic cultivation, The Carnivorous Plant FAQ (Barry Rice)
5. Nepenthes: advanced cultivation, The Carnivorous Plant FAQ (Barry Rice)
6. Thumbnail guidelines on growing a tropical pitcher plant, The Carnivorous Plant FAQ (Barry Rice)