It is possibly the smallest species in the genus and does not appear to have a climbing stage.

[2] Nepenthes argentii inhabits subalpine shrubbery "with a smooth wind-clipped canopy 30 cm tall on an ultrabasic ridge".

[1] It grows at an elevation of 1400–1900 m.[3] On Mount Guiting-Guiting, N. argentii is sympatric with N. sibuyanensis at around 1600 to 1770 m.[2][4] A taxon resembling N. alata grows on Mount Guiting-Guiting at lower elevations of 800 to 1000 m;[5] it was described as N. graciliflora by Adolph Daniel Edward Elmer.

[6] Other plant species endemic to the mountain include Lobelia proctorii[7] and Rhododendron rousei.

[8] Nepenthes argentii has no known natural hybrids, although it may hybridise with N. sibuyanensis.