Subsequent seed-grown plants have themselves set seeds, and the species has been replanted on the island, the adjoining mainland, and in public and private gardens around New Zealand.

The Three Kings are located around 55 kilometres (34 mi) northwest of Cape Reinga, and at the time were relatively unknown botanically, with the only collecting expeditions in 1887 and 1889 (both by Thomas Cheeseman, director of Auckland Museum, who had only a few hours ashore), 1928, and 1934.

[8] Baylis spent a week on the island in November–December 1945, and collected samples of 83 species of plants for Auckland Museum.By this time wild goats had eaten the place out.

I located these places by climbing trees at every vantage point and reached them deviously via bluffs and screes since except in the main valley they were, even for goats, a bit inaccessible.

[9]Four of Baylis's discoveries were new to science, including Suttonia dentata (now Myrsine oliveri), Tecomanthe speciosa (which like P. baylisiana was represented by a single living individual), and Brachyglottis arborescens.

[9]He noted that the 4.5-metre tree was living on a seaward scree slope of greywacke boulders at an altitude of 233 metres, with pōhutukawa (Meterosideros excelsa), kānuka (Kunzea ericoides), coastal maire (Nestegis apetala), and whārangi (Melicope ternata) growing nearby.

Corynocarpus had until recently been considered to be in the family Anacardiaceae, which is where Oliver placed this species, erecting a new genus Plectomirtha to contain it and giving it the specific epithet baylisiana in recognition of the plant’s discoverer Geoff Baylis.

[15][6] A DNA phylogeny confirmed its distinctiveness, placing P. corymbosa and P. endlicheri as each other's closest relatives and P. baylisiana as sister taxon to both of them, the three species diverging some time within the last 9 million years.

[17] Manawatāwhi / Great Island had been inhabited by Māori for at least 200 years, during which time they farmed goats and pigs and cleared the forest – along the coast predominantly puka, Meryta sinclairii – from almost all cultivatable land.

When Cheeseman landed in 1887, the island was almost covered with kānuka, and regenerating forest trees were plentiful (although Meryta sinclairii did not reappear until 1946, which led Baylis to speculate that some goats may still have been present and preventing this species from re-establishing).

[22] The government survey party decided that Great Island needed to be stocked with animals that could feed shipwrecked sailors, so on Cheeseman's second collecting trip in 1889 four goats were released.

At the time Baylis visited in 1945, nearly 50 plant species had been driven locally extinct on Great Island, and others had been almost eliminated, with only a few or a single individual surviving in places inaccessible to goats.

Attempts to root cuttings from the crown of the tree by both the DSIR Plant Diseases Division and the commercial New Plymouth nursery Duncan and Davies had failed.

A year later the shoots were there, the Naval launch on which I was a guest gave them a quick passage to New Plymouth which happened to be its next port and Mr Smith soon placed the survival of "Plectomirtha" beyond doubt.

In the late 1980s, fruit was found for the first time on the one tree remaining in the wild, indicating that on occasion viable pollen was produced and self-fertilisation could occur, a rare occurrence in dioecious plants.

[25] By 1998 hundreds of saplings had been grown from seed, but these were not immediately replanted on Great Island, for fear of introducing bacteria or fungal disease which could attack the remaining wild tree.

[25] In 2010 the Department of Conservation planted 1,600 P. baylisiana seeds from mainland fruit back on Great Island, after carefully treating them to avoid introducing pathogens.