Nepenthes micramphora

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Nepenthes micramphora
A rosette plant of Nepenthes micramphora with lower/intermediate pitchers
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Nepenthaceae
Genus: Nepenthes
Species:
N. micramphora
Binomial name
Nepenthes micramphora

Nepenthes micramphora is a tropical pitcher plant known only from Mount Hamiguitan on the island of Mindanao in the Philippines.[1] It is a highland plant growing at elevations of 1100–1635 m.[1]

Nepenthes micramphora is closely allied to N. abgracilis and N. cid, both also from Mindanao, and together these species comprise the informal "N. micramphora group".[2]

The

specific epithet micramphora is derived from the Greek mikros (small) and Latin amphora (amphora, urn), and references the tiny pitchers of this species.[3]

Botanical history

Nepenthes micramphora was

Musuan, Bukidnon, the Philippines.[1] It was collected on 31 January 2005, from Mount Hamiguitan, on the trail from San Isidro, at an altitude of 1300–1600 m.[1]

Inflorescence measurements for the formal description were taken by

type locality on 22 July 2008, since herbarium material of the floral structures could not be located.[1]

Description

Nepenthes micramphora is a climbing plant growing to a height of 2.5 m.

internodes up to 15 mm long.[1]

A typical upper pitcher

Leaves

Leaves are

midrib, while pinnate veins are numerous. Tendrils are up to 7.5 cm long and 1 mm wide.[1]

Pitchers

Rosette and lower pitchers are narrowly

ventral surface of the pitcher cup, although these may be reduced to ribs.[3] The wings bear fringe elements measuring around 3 mm and spaced 2.5–3 mm apart. Only the basal third of the interior surface of the pitcher is glandular. The peristome is cylindrical and up to 0.8 mm wide, bearing ribs up to 0.1 mm high and spaced 0.1 mm apart.[3] Teeth are not visible on the inner margin of the peristome.[2] The pitcher lid or operculum may be elliptic, ovate, or orbicular, and generally has a cordate base.[3] The lid lacks appendages[3] and measures up to 2 cm in length by 1.8 cm in width, being slightly wider than the pitcher mouth.[1] The nectar glands of the lower lid surface number more than 100.[2] A branched or divided[3] spur (≤3 mm long) is inserted near the base of the lid.[1]

A rosette plant with a bright red stem

Upper pitchers are produced from an early age.[3] They may be infundibular throughout[1] or narrowly infundibular in their basal part, becoming narrower and roughly cylindrical above.[3] They are broadest in the middle or in the upper portion.[2] Aerial pitchers are larger than their terrestrial counterparts, growing to 6.7 cm in height by 2 cm in width (although more often around 4 cm by 1.7 cm).[3] The pitcher lid is of the same width as the mouth. Wings are always reduced to ribs.[3] In other respects, upper pitchers are similar to the lower traps.[1]

Inflorescence

Nepenthes micramphora has a racemose inflorescence measuring up to 35 cm in length by 6 mm in width. The peduncle itself may be up to 8 cm long and 1 mm wide. Flowers are borne on one-flowered, non-bracteate pedicels (3–4 mm long), of which there are between 20 and 40 on the inflorescence. The ovate tepals measure up to 2.5 mm in length by 1.2 mm in width. Fruits are up to 20 mm long.[1]

Indumentum

The stem, lamina, and pitchers are glabrous. An inconspicuous indumentum of simple, rusty brown hairs (0.1 mm long) covers the inflorescence.[1]

Ecology

Distribution

A stunted tree growing in the "Bonsai Forest" of Mount Hamiguitan

Nepenthes micramphora has only been recorded from the highland slopes of

above sea level to the summit at 1635 m.[1]

Habitat

This species grows

natural hybrids
have been observed with certainty.

Conservation status

In his 2009 book, Pitcher Plants of the Old World, Stewart McPherson writes that N. micramphora is "not currently threatened" owing to its extensive populations on Mount Hamiguitan and the fact that visitors are only permitted to climb the mountain with the assistance of a guide.[3] The future of wild populations of N. micramphora will be further secured if provincial officials of Davao Oriental are successful in their bid to gain recognition of Mount Hamiguitan as a UNESCO World Heritage Site.[3][6]

Related species

N. micramphora group

type descriptions
, showing various aspects of vegetative morphology

Nepenthes micramphora gives its name to the informal "N. micramphora group", which also includes

N. villosa species groups).[7]

Nepenthes abgracilis, N. cid and N. micramphora are united by aspects of pitcher and stem morphology as well as shared habitat preferences. Cheek and Jebb identified seven diagnostic characters that they used to define the group:[2]

  1. submontane
    habitat;
  2. stems terete;
  3. peristome slender, cylindrical, 0.8–2 mm wide;
  4. peristome ridges low, about 0.1 mm high, inconspicuous;
  5. inner edge of peristome without visible teeth (in natural position);
  6. lower surface of lid lacking a basal ridge and appendage;
  7. lid nectar glands >100, monomorphic, large (ca. 0.5 mm diam.) with a narrow border, ± evenly spread over the lid

These species show some similarities to those of the

N. alata group, but differ in lacking a basal ridge or appendage on the lower surface of the lid.[2]

Nepenthes cid differs from the other two species of the N. micramphora group in growth habit (it is epiphytic as opposed to terrestrial), indumentum development (vegetative parts hairy as opposed to subglabrous), and in having a distinct petiole (versus sessile in the other two).[2] Both it and N. abgracilis have entire spurs, as compared to branched in N. micramphora.[2]

Nepenthes micramphora is most easily distinguished from N. abgracilis by its upper pitchers, which are more-or-less infundibular (versus subcylindric in N. abgracilis), narrowest at the base and widest in the middle or upper half (versus widest near the base), and much smaller in all respects (≤6.7 cm versus c. 16 cm high).[2]

Other similar species

A basal rosette of N. bellii, with lower pitchers and a climbing stem trailing off to the right

Nepenthes micramphora is very similar to N. bellii of northern Mindanao in terms of the morphology of its stem, lamina, and inflorescence. Indeed, prior to the description of N. micramphora in 2009, the species was misidentified as N. bellii on its native Mount Hamiguitan.[8][9] Nepenthes micramphora is smaller in all respects and can be distinguished on the basis of its pitchers, which differ markedly in shape, size, peristome width, and tendril length. It also produces a greater abundance of pitchers on its rosettes — up to 7 live traps have been recorded at any one time.[1]

Nepenthes gracilis also bears a superficial resemblance to N. micramphora in the size and shape of its leaves, but this species is absent from the Philippines.[3]

Natural hybrids

Nepenthes micramphora has no confirmed

natural hybrids, although certain plants from Mount Hamiguitan may represent crosses involving it and N. hamiguitanensis, N. justinae[5] (previously identified as N. mindanaoensis), and N. peltata.[10] Plants that were originally thought to represent a natural hybrid between N. micramphora and N. peltata[3] are now recognised as belonging to a distinct species of possible hybridogenic origin, N. hamiguitanensis.[4]

References

  1. ^ a b c d e f g h i j k l m n o p q r s t Heinrich, V., S.R. McPherson, T. Gronemeyer & V.B. Amoroso 2009. Nepenthes micramphora (Nepenthaceae), a new species of Nepenthes L. from southern Mindanao, Philippines. In: S.R. McPherson Pitcher Plants of the Old World. Volume 2. Redfern Natural History Productions, Poole. pp. 1314–1319.
  2. ^
    doi:10.11646/phytotaxa.151.1.2
  3. ^ a b c d e f g h i j k l m n o p q r McPherson, S.R. 2009. Nepenthes micramphora V.Heinrich, S.McPherson, Gronemeyer & Amoroso. In: S.R. McPherson Pitcher Plants of the Old World. Volume 2. Redfern Natural History Productions, Poole. pp. 713–719.
  4. ^ a b c Gronemeyer, T., A. Wistuba, V. Heinrich, S. McPherson, F. Mey & A. Amoroso 2010. Nepenthes hamiguitanensis (Nepenthaceae), a new pitcher plant species from Mindanao Island, Philippines. In: S.R. McPherson Carnivorous Plants and their Habitats. Volume 2. Redfern Natural History Productions, Poole. pp. 1296–1305.
  5. ^
    doi:10.3390/plants5020023
  6. ^ UNESCO National Commission of the Philippines 2008. Mount Apo and Mount Hamiguitan: Sanctuaries of Endemism in Mindanao. UNESCO.
  7. doi:10.5852/ejt.2013.69
  8. doi:10.3767/000651909X474113
  9. doi:10.1016/j.sjbs.2010.07.003
  10. Field Guide to the Pitcher Plants of the Philippines
    . Redfern Natural History Productions, Poole.

External links

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