"Nepenthes northiana" has a racemose inflorescence. The peduncle is up to 60 cm long, while the rachis is up to 40 cm long, although male inflorescences are generally shorter. Partial peduncles are mostly two-flowered and reach 50 mm in length. The seeds of "N. northiana" are quite atypical of the genus in that they have short appendages, a large embryo, and are unusually woody in texture. Their structure prevents them from being carried great distances by wind. A study of 120 pollen samples taken from a herbarium specimen ("J.H.Adam 2378", collected at an altitude of 30 m) found the mean pollen diameter to be 29.8 μm (SE = 0.4; CV = 6.0%).