| Nepenthes adnata | |
|---|---|
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| Lower pitcher ofNepenthes adnata | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Order: | Caryophyllales |
| Family: | Nepenthaceae |
| Genus: | Nepenthes |
| Species: | N. adnata |
| Binomial name | |
| Nepenthes adnata | |
Nepenthes adnata/nɪˈpɛnθiːzædˈnɑːtə/ is a tropicalpitcher plantendemic to theIndonesian province ofWest Sumatra, where it grows at elevations of 600 to 1200 m above sea level. Thespecific epithetadnata isLatin for "broadly attached" and refers to the base of thelamina.
Nepenthes adnata was first collected byWillem Meijer on August 24, 1957.[note a] Theholotype,Meijer 6941, was collected on that date near the riverTjampo, east ofPayakumbuh,Taram,West Sumatra, at an elevation of 1000 m. It is deposited at theNational Herbarium of the Netherlands inLeiden.[3]
The species was first described in 1986 byMitsuru Hotta andRusjdi Tamin based on specimens the authors collected nearHarau inWest Sumatra.[4] However, the description was invalid as it lacked a Latin diagnosis.[5] This was provided eight years later byJan Schlauer.[2]
Nepenthes adnata is a diminutive species. The stem is cylindrical in cross section and may be climbing or drooping. It rarely exceeds 2 m in length and 3 mm in diameter.Internodes are up to 10 cm long.[3]
Leaves arecoriaceous andsessile. Thelamina islanceolate-ellipsoidal and may be up to 10 cm long and 2 cm wide. It has anadnate base and an obtuse to acute apex. Two to three longitudinal veins are present on either side of themidrib.Pinnate veins are not easily distinguished.Tendrils may be up to 5 cm long.[3]
Rosette and lower pitchers are ovoid in the lower third and cylindrical above. They are small, reaching only 10 cm in height and 2.5 cm in width. A pair of fringed wings (≤3 mm wide) runs down the front of terrestrial pitchers. The glandular region covers only the lower third of the inner pitcher surface. The pitcher mouth is round and slightly oblique throughout. The cylindricalperistome is up to 2 mm wide and bears indistinct teeth.[3] The peristome is roughly symmetrical in cross section, with the inner portion accounting for around 54% of its total cross-sectional surface length.[6] The lid oroperculum isorbicular andcordate at the base. Multicellular hairs are sometimes present on its upper surface. An unbranchedspur (≤2 mm long) is inserted at the base of the lid.[3]
Upper pitchers are ovoid in the lower quarter and cylindrical toinfundibular above. In aerial pitchers, the wings are usually reduced to ribs, but sometimes bear fringe elements. In most other respects, they are similar to lower pitchers.[3]
Nepenthes adnata has aracemoseinflorescence. Thepeduncle is up to 8 cm long. In male plants, therachis reaches 10 cm in length, while in female plants it rarely exceeds 7 cm.Pedicels lackbracteoles and are up to 10 mm long.Sepals are lanceolate-ovate and around 4 mm long. Fruits are up to 40 mm long.[3]
Short brown hairs are present on the edges of the lamina. The stem and lamina bear a sparseindumentum of simple white hairs (≤2 mm long). Inflorescences are covered with short, red-brown hairs.[3]
The pitchers ofN. adnata are generally speckled with reddish-purple blotches. The peristome is usually dark purple. The inner pitcher surface is white to light green. The stem and lamina are green throughout.
Nepenthes adnata varies little across its range. Consequently, noinfraspecific taxa have been described.[3]
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Nepenthes adnata isendemic to the mountains of theTjampo river region ofWest Sumatra. Most ridges in this area have an elevation of just below 1000 m, although several exceed this height.[7] The species has an altitudinal distribution of 600 to 1200 m above sea level.[8][9] It grows onmossysandstone cliff faces amongst dense vegetation. The habitat is moist and receives diffused sunlight.[3][10]
In its natural habitat, the species occurs sympatrically withN. tenuis and grows in close proximity toN. albomarginata,N. ampullaria,N. eustachya,N. gracilis,N. longifolia, andN. reinwardtiana. Despite this,N. adnata has no knownnatural hybrids.[3][8] InKelok Sembilan, the species has been found to grow alongsideUtricularia striatula, a distantly relatedcarnivorous plant.[3]
Only two collections of this species have been made and these correspond to two populations separated by several kilometres of mountainous terrain. The species may be more widespread in the region, but most cliffs in the Tjampo river area are virtually inaccessible by foot, making the discovery of new localities unlikely in the near future. The only population that is easily accessible is very small and frequently visited by plant collectors.Charles Clarke considers this population "severely threatened." The habitat of this species may be threatened in the near future by fires deliberately started to clear forest foragricultural purposes.[3]
Nepenthes adnata has no obvious close relatives within the genus.Rusjdi Tamin andMitsuru Hotta considered the species to be closely related toN. tentaculata,N. gracillima, andN. gracilis.[4] BothJan Schlauer andJoachim Nerz[2] as well asMatthew Jebb andMartin Cheek[5] agreed thatN. adnata andN. tentaculata are related, whileJ. H. Adam,C. C. Wilcock and M. D. Swaine considered the two taxa conspecific.[11] However,Charles Clarke does not support this interpretation, stating that the similarities between the two species are probably coincidental and that the closest relatives ofN. adnata "are more likely to be other Sumatran species such asN. gymnamphora,N. longifolia orN. albomarginata."[3] Clarke points out that the multicellular hairs sometimes exhibited byN.adnata, which several authors have used to suggest a relationship withN. tentaculata, occur in rosette pitchers of many other species, especiallyN. rafflesiana.[3]
The pitchers ofN. adnata are similar to those ofN. tobaica, although the stem and lamina are quite different. They also bear a superficial resemblance to those of a form ofN. gymnamphora fromMount Sorik Merapi.[3] Seedlings ofN. adnata andN. longifolia are virtually indistinguishable, although mature plants have few morphological features in common.N. adnata also shares withN. albomarginata a similar indumentum and ecology.[3]
In 2001, Clarke performed acladistic analysis of theNepenthes species of Sumatra andPeninsular Malaysia using 70 morphological characteristics of each taxon. The following is a portion of the resultantcladogram, showing "Clade 6", which is only weakly supported at 50%. The sister pair ofN. angasanensis andN. mikei has 79% support.[3]
 N. adnata |  |
