Nepenthes gracilis (from Latin: gracilis = thin, slender), or the Slender Pitcher-Plant, is a very common lowland pitcher plant that is widespread in the Sunda region. The pitchers are relatively unremarkable with a very thin peristome and no unusual morphological features. Despite being a widespread plant, natural hybrids between N. gracilis and other species are quite rare.

Taxonomy

In 2001, Charles Clarke performed a cladistic analysis of the Nepenthes species of Sumatra and Peninsular Malaysia using 70 morphological characteristics of each taxon. The following is a portion of the resultant cladogram, showing part of "Clade 6". The sister pair of N. angasanensis and N. mikei has 79% support.

}} }} }}

Infraspecific taxa

Despite varying little across its range, N. gracilis has a number of infraspecific taxa. Most of these are no longer considered valid.

• Nepenthes gracilis f. angustifolia (Mast.) Hort.Westphal (1993)
• Nepenthes gracilis var. angustifolia (Mast.) Hort.Weiner in sched. (1985)
• Nepenthes gracilis var. arenaria Ridl. ex Macf. (1908)
• Nepenthes gracilis var. elongata Bl. (1852)
• Nepenthes gracilis var. longinodis G.Beck (1895)
• Nepenthes gracilis var. major Hort.Lindsay ex Dixon (1889)
• Nepenthes gracilis var. teysmanniana (Miq.) Beck (1895)

Natural hybrids

The following natural hybrids involving N. gracilis have been recorded.

• N. ampullaria × N. gracilis [=N. × trichocarpa]
• (N. ampullaria × N. gracilis) × N. bicalcarata [=N. × trichocarpa × N. bicalcarata]
• N. bicalcarata × N. gracilis [=N. × cantleyi]
• ? N. eustachya × N. gracilis
• N. gracilis × N. mirabilis [=N. × ghazallyana, N. × grabilis, N. neglecta?]
• N. gracilis × N. northiana [=N. × bauensis]
• N. gracilis × N. rafflesiana
• N. gracilis × N. reinwardtiana
• N. gracilis × N. sumatrana

References

• Adam, J. H., R. Omar & C. C. Wilcock 2002. OnLine Journal of Biological Sciences 2(9): 623–625.
• Athauda, S.B.P., K. Matsumoto, S. Rajapakshe, M. Kuribayashi, M. Kojima, N. Kubomura-Yoshida, A. Iwamatsu, C. Shibata, H. Inoue & K. Takahashi 2004. (manuscript BJ20031575) Biochemical Journal 381(1): 295–306.
• Aung, H.H., L.S. Chia, N.K. Goh, T.F. Chia, A.A. Ahmed, P.W. Pare & T.J. Mabry 2002. Phenolic constituents from the leaves of the carnivorous plant Nepenthes gracilis. Fitoterapia 73(5): 445–447.
• Kato, M. 1993. Floral biology of Nepenthes gracilis (Nepenthaceae) in Sumatra. American Journal of Botany 80(8): 924–927.
• Lam, S.Y. 1982. Tripteroides aranoides (Theobald) in two pitcher plants, Nepenthes ampullaria Jack and N. gracilis Korth., at Kent Ridge (Diptera: Culicidae). B.Sc (Hons.) Thesis, National University of Singapore.
• Mogi, M. & K.L. Chan 1997. Variation in communities of dipterans in Nepenthes pitchers in Singapore: Predators increase prey community diversity. Annals of the Entomological Society of America 90(2): 177–183.
• Mokkamul, P., A. Chaveerach, R. Sudmoon & T. Tanee 2007. Pakistan Journal of Biological Sciences 10(4): 561–567.
• Moran, J.A., W.E. Booth & J.K. Charles 1999. Annals of Botany 83: 521–528.
• Normawati, Y. 2002. The effect of stem length on pitcher and inflorescence production in Nepenthes gracilis and Nepenthes mirabilis at Serendah Selangor. B.Sc. Thesis. Universiti Kebangsaan Malaysia.