Nepenthes rhombicaulis
Description
Terrestrial climber to 20 m tall.
Leaves sessile, those of rosettes and short shoots scattered, lanceolate, several cm long;
Inflorescence 30-40 cm long;
Fruits fusiform, valves lanceolate 20-25 by 5 mm.
Taxonomy
The description above is largely taken from the protologue. Nepenthes rhombicaulis is extremely poorly known although reported in the protologue as being ‘common’ on the mountains surrounding Lake Toba. Only the type collection exists. Subsequent purported field observations ( ) have not been supported by voucher specimens and their descriptions and photographs do not appear to match the type. The combination of a sharply 4-angled stem, absence of upper pitchers and presence of an apical appendage on the lower surface of the lower pitcher lid (not seen in the SING specimen) is unique: each are individually unusual characters within the genus.