Initially described as a species of Nothopanax by Oliver (1926), this species was then shifted to Neopanax by Allan (1961). Later, Philipson (1965) placed the species in Pseudopanax where it remained at that rank until Sykes (1977) treated it as variety of P. arboreus, after which, on further consideration he then reinstated the tree to species rank (Sykes 1993).

Pseudopanax kermadecensis is a small tree endemic to New Zealand, where it only is found on Raoul Island (Kermadec Islands). The species has an extent of occurrence (EOO) of 45 km². It grows in wet and dry forests at 20–516 m altitude. Since feral goats was eradicated from the island in 1984 the species has recovered well and there are no major threats, apart from the risk of volcano eruptions. Due to the prominent risk of a volcano eruption, and the small range, this species is assessed as Near Threatened, nearly meeting the conditions for Vulnerable D2.

This species is endemic to New Zealand, occurring only on the Raoul Island in the Kermadec Islands. The total size of the Raoul Island is only 29.38 km², giving a Minimum Convex Polygon extent of occurrence of approximately 45 km². Distribution map is generalised.

No accurate population estimate for this species is known. Sykes (1969, 1977) noted it was extremely uncommon due to goat browsing pressure with most trees, saplings and seedlings occurring as epiphytes on tree ferns (Alsophila kermadecensis, A. milnei) or on cliff refugia. However, following the eradication of feral goats (Capra hircus) in 1984 (Parkes 1984) the species rapidly spread from these sites across the island, and it is now commonly found in all forested habitats except the absolute coastal fringe forest on Raoul Island (29.38 km²). The population is still recruiting and expanding its range and at most sites comprises numerous seedlings, subadults and adults.

Pseudopanax kermadecensis is a gynodioecious tree found throughout the two main forest associations of Raoul Island dubbed ‘dry’ and ‘wet’ forest by Oliver (1910). Ranging from near sea level to the island’s summit Moumoukai (516 m asl). It is, however, most common in the ‘wet’ forest where it is a common understory tree, although in places such as along ridge lines, above the crater or fringing old slip scars), and along ravines, especially toward the ravine heads (de Lange 2023) it can form part of the canopy. It is only uncommon in those sites dominated by nikau (Rhopalostylis baueri). In these habitats it co-associates with Metrosideros kermadecensis, Melicytus ramiflorus subsp. ramiflorus, and in the upper portion of the island Ascarina lucida var. lanceolata.

Pseudopanax kermadecensis was seriously threatened by feral goat browsing (Oliver 1910; Sykes 1969, 1977). Feral goats once rampant on Raoul Island, were eradicated in stages from 1937 to 1984 (Parkes 1984). From the 1980's onwards P. kermadecensis rapidly recovered spread across the island (Sykes 1993). P. kermadecensis is now an abundant component of most of the forested portions of Raoul Island (de Lange 2023). It is no longer considered threatened and is currently listed as ‘At Risk / Naturally Uncommon’ by the New Zealand Indigenous Vascular Plant Threat Listing Panel (de Lange et al. 2018). The only major risk to the species is volcanic eruptions, a risk which all Kermadec biota face as Raoul Island volcano is extremely active.

This tree is occasionally cultivated in Aotearoa / New Zealand.

Provided Raoul Island remains predator free Pseudopanax kermadecensis is unlikely to be threatened. The only major risk to the species is volcanic eruptions, a risk which all Kermadec biota face as Raoul Island volcano is extremely active. For example, it has erupted at least five times since eruptions were first documented from there in the 1830's (Gentry 2013). Natural events aside the main risk to the species, and indeed all the island’s biota, is the potential for new incursions of pest species – as such it is imperative that biosecurity measures currently in place are maintained. During the sars-cov-2 outbreak the resident rangers on Raoul Island were evacuated back to Aotearoa / New Zealand (2020) and since that time there has not been a continuous human presence on the island. This is a risk as the island is frequently visited by boats / ships and illegal landings could be a source of new diseases / pest incursions.

New Zealand Threat Classification System assessed this species as ‘At Risk / Naturally Uncommon’ Qualified ‘CD’ [Conservation Dependent], ‘IE’ [Island Endemic], ‘OL’ [One Location] (de Lange et al. 2018, 2024).