Nepenthes argentii

Nepenthes argentii

Synonymy

Nepenthes argentii Jebb & Cheek in Blumea 42(1): 19, f. 1. 1997 sec. Cheek & Jebb 2001
    • Holotype: Philippines, Sibuyan Isl., alt. 1400 m, 27 Aug 1989, Argent & Reynoso 89119 (K).
    • Isotype: Philippines, Sibuyan Isl., alt. 1400 m, 27 Aug 1989, Argent & Reynoso 89119 (PNH).

Description

Terrestrial, monopodial shrub c. 30 cm tall. Stem erect, terete, 2-4 mm wide, 22 cm apparently buried in leaf litter, 4 cm above ground, with leaves congested (4 per cm of stem), internodes obscured. Leaves thickly coriaceous, more or less petiolate; blade obovate-oblanceolate, 3.5-4 by 1.4-2.2 cm, apex obtuse to truncate, base cuneate-decurrent; petiole 1-1.8 cm long, sheathing, clasping the stem for about half its circumference, not auriculate or decurrent. Longitudinal nerves 1 or 2 on each side of the midrib in the marginal half, mostly inconspicuous. Pennate nerves inconspicuous. Lower pitchers infundibuliform-shortly cylindrical, 4-4.7 by 2.2-2.4 cm, with two fringed wings 1.5-2 mm wide, fringed elements 3 mm long, often grouped and webbed together in clusters of 2-4, elements or groups of elements 1-2 mm apart; mouth subcircular, almost flat, abruptly rising in the rear to provide a stout column 5 mm high, 2.5 mm wide, for the lid; peristome subcylindrical, c. 1 mm wide, ribs laterally flattened, highly pronounced, 0.1-2 mm high, 5 mm apart, inner surface with stout, incurved teeth, up to 1 mm long near the column, outer surface never sinuate, adnate to underside of lid, forming a short transverse wall c. 7 by 2-3 mm high, with triangular teeth below; lid suborbicular, to 1.3 by 1.8 cm, apex rounded, base cordate, lower surface lacking appendages, glands very dense, pit-like, near the centre elliptic, 0.2 by 0.3 mm, near the edge orbicular, 0.15 mm wide; spur stout, rounded 1-1.5 mm long. Upper pitchers apparently not formed. Male inflorescence unknown. Fruit (mature) unknown. Seed unknown. Indumentum absent from stem and upper surface of leaves, lower surface of leaf and tendril densely invested with persistent patent red hairs c. 2 mm long, simple or with a short inconspicuous branch, remainder of blade with red sessile glands only. Pitcher outer surface and lid densely invested with minute reddish stellate hairs 0.1-0.2 mm wide, with 3-5 erect arms, and with sparser appressed, twisted, sub-simple hairs 2-3 mm long bearing up to 5 or 6 short branches, giving a slightly matted appearance and felty texture. Inflorescence axis with whitish hairs c. 0.6 mm long, particularly at base and apex; tepals glabrescent; carpels densely hairy with appressed reddish hairs. Colour of pitchers buff mottled red, peristome dark purple, lid spotted red underneath, mostly mottled red on top. Young fruit brown.A

Notes

Nepenthes argentii is unusual in that it has a long, vertical, subterranean rhizome. It seems that the stem may grow slowly upwards, keeping pace with the accumulation of organic matter on the surface which continually buries the lower portion of the stem as with Drosera rotundifolia in a Sphagnum bog. More field studies are needed to verify this hypothesis. The diminutive stature, lack of upper pitchers and lack of climbing habit are also unusual in the genus and this species must contend as the smallest at maturity of all. Argent (pers. comm.) reports that the plants he collected were completely concealed below the low (c. 30 cm high), wind-clipped shrubbery and that the pitchers were buried in the substrate amongst grasses or sedges. Plants were only detected by the inflorescences emerging above the shrub canopy. Several other species of Nepenthes known from ultramafic derived soils (e.g. N. rajah, N. burbidgeae and N. macrovulgaris, all from Sabah and unrelated) are entirely restricted, as far as known, to such soils and this may be the case with N. argentii.
Nepenthes bellii of Surigao Province, Mindanao is the only other Philippine species with subglobose lower pitchers, with upper pitchers absent or rare and with grouped fringed elements of the pitcher wings. Nepenthes argentii differs in the lack of climbing habit and the subpetiolate oblanceolate leaves with truncate apices. Nepenthes argentii is unique in the peristome being adnate to the underside of the lid.A

Distribution (General)

Philippines: Sibuyan, Romblon ProvinceA

Etymology

Nepenthes argentii commemorates one of the collectors of the only known specimen, George Argent, a botanist of the Royal Botanic Gardens, Edinburgh, well known for his fieldwork in Borneo, Philippines, and New Guinea, and for his research on the species of Musa and Rhododendron.A

Habitat

Subalpine shrubbery with smooth wind-clipped canopy 30 cm tall on a ridge of ultramafic rock; 1400 m.A

Bibliography

A. Cheek, M.R. & Jebb, M.H.P. 2001: Flora Malesiana - Nepenthaceae, Series I, Volume 15

Images

Specimens

CountryDateCollector + collecting numberHerbariaTypeScanDerivatives
Philippines1989-08-27Argent & Reynoso 89119K, PNH
Citation: Philippines, Sibuyan Isl., alt. 1400 m, 27 Aug 1989, Argent & Reynoso 89119.

Specimen summary: K
Holotype of Nepenthes argentii Jebb & Cheek

Specimen summary: PNH
Isotype of Nepenthes argentii Jebb & Cheek