Nepenthes tenax

Nepenthes tenax

Synonymy

Nepenthes tenax C.Clarke & R.Kruger in Austrobayleya 7(2): 319 (-324; fig. 1). 2006 sec. McPherson 2009
    • Type (designated by Clarke, C.M. & Kruger, R. 20061): Australia, Queensland. Cook District: Head of Cowal Creek near Cape York, F. W. Whitehouse s.n. (holo: BRI [AQ46887]).
  • 1. Clarke, C.M. & Kruger, R. 2006: Nepenthes tenax C.Clarke and R.Kruger (Nepenthaceae), a new species from Cape York Peninsula, Queensland. – Austrobayleya 7(2)

Description

Monopodial shrub, new stems generally arising from the rootstock after the main stem dies. Indumentum: all young parts of the plant sparsely to densely covered with short simple and stellate hairs, most of which are caducous. Stems terete, up to 0.5 (-1) m long, 2-6 mm thick, internodes 8-10 mm long. Rosette leaves sessile, very narrowly linear, up to 60 mm long and 8 mm wide, margins more or less parallel throughout, contracting gradually; apex acute; base slightly widened, clasping the stem for two-thirds of its circumference; tendrils up to 25 mm. Leaf blades of the erect stems subpetiolate, lanceolate, up to 110 mm long and 25 mm wide, the margins held close together so that the blade forms a highly pronounced "V-shape" in cross section; longitudinal veins 3 or 4 on each side of the mid-rib, often indistinct on dried specimens, pennate veins forming a densely branched network arising from the midrib and spreading towards the margins; apex acute; base clasping the stem for half to two-thirds of its circumference, not decurrent. Tendrils up to 60 mm long, highly tensile, with a tight curl (or occasionally a pronounced kink) in the middle, insertion simple. Upper two­ thirds of the aerial pitchers held above the leaf blade. Rosette pitchers rarely produced, ovoid to infundibular in the lower third, cylindrical above, up to 55 mm high and 10 mm wide; two wings, up to 2 mm wide, bearing multicellular fringe elements (up to 2 mm long) that run from the peristome to the lower quarter of the pitcher. Tendril insertion at the front or side. Mouth round, oblique throughout, peristome cylindrical , up to 2 mm wide, ribs distinct but minute, teeth distinct, but very short (up to 0.2 mm long). Inner surface glandular in the portion below the hip, glands round, recessed in the upper portion, up to 0.1 mm wide, c. 1500 per cm2• Lid wider than the pitcher mouth and held close to the peristome, resulting in a narrow opening to the pitcher, broadly ovate, indented at the apex, no appendages. Spur simple or bifid, up to 2 mm long. Aerial pitchers infundibular throughout, with or (more commonly) without a hip about one quarter of the way up from the bottom, up to 110 mm high and 20 mm wide, broadest at the mouth. Wings reduced to ribs and lacking multi-cellular fringe elements. Tendril joins the pitcher at the rear, but is generally positioned so that the apex of the leaf blade is pressed against the side of the pitcher in the lower quarter. Inner surface glandular in the lower one-quarter to one-third, glands as in the lower pitchers. Mouth round, oblique throughout, peristome cylindrical, up to 2 mm wide, ribs distinct but minute, up to 0.3 mm wide, teeth distinct but short, up to 0.4 mm long. Lid ovate, indented at the apex, no appendages, considerably broader than the mouth and positioned close to the peristome, so that the opening of the pitcher is very narrow. Glands on the underside of the lid ovate, up to 0.2 mm long, c. 100 per cm2 near the centre. Towards the margins, the glands are smaller (up to 0.1 mm long) and somewhat more numerous (up to 150 per cm2). Inflorescence a raceme, peduncle up to 80 mm long, rachis up to 80 mm long. Pedicels (or, occasionally, two-flowered partial peduncles) up to 8 mm long, lacking bracteoles, sepals ovate, up to 4 mm long; column of male flowers :s; 4 mm long. Mature fruits up to 12 mm long.A

Conservation

According to the IUCN guidelines (IUCN 2001), a category of LR(cd) (= lower risk, conservation dependent) is proposed, as all known populations occur within protected areas.A

Distribution (General)

Australia, Queensland, northern Cape York peninsula.A

Etymology

The Latin, tenax, means tenacious and refers to the ability of this species to produce stems and pitchers that remain upright in open areas, despite regular exposure to strong winds and without the support of surrounding objects or plants, a characteristic that is not observed in other Nepenthaceae.A

Habitat

Biogeographic region: CYP. Apparently confined to open sandy substrates or saturated peat in the lower portions of swamps on floodplains. The surrounding habitat is described by Fox et al. (2001) as open heath, Type Cl5. A

Bibliography

A. Clarke, C.M. & Kruger, R. 2006: Nepenthes tenax C.Clarke and R.Kruger (Nepenthaceae), a new species from Cape York Peninsula, Queensland. – Austrobayleya 7(2)

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
Australia, Queensland. Cook District: Head of Cowal Creek near Cape York, F. W. Whitehouse s.n. (holo: BRI [AQ46887]).
Citation: No Citation available. This specimen either has no or multiple field units.