Bartlett's rātā's range covers the northern tip of the Aupōuri Peninsula, in three patches of dense forest remnants near Piwhane / Spirits Bay.

Bartlett's rātā typically begins life as an epiphyte; it inhabits lowland forests and is usually found growing near wet areas.

The species has a high chance of becoming extinct unless immediate conservation measures are taken to stop its ongoing decline; which has been attributed to land use changes following human settlement and the introduction of common brushtail possums.

[3][16] The species was accidentally discovered while Bartlett was searching for liverworts in the area and instead found a M. bartlettii specimen growing at the base of a large tree.

Bartlett realised it was a new species of rātā but was unable to reach any of the branches, so he instead took fragments of the bark to botanist John Dawson of the Victoria University of Wellington.

Dawson thought the find was northern rātā, but Bartlett continued to believe it was a new species, so he later returned to the area where he found the specimen and was able to collect a branch by shooting one off with his rifle.

[25] In 2018, two New Zealand botanists, Carlos Lehnebach and Karin van der Walt, analysed the pollination and the flower development of Bartlett's rātā.

[27] In 2021, the New Zealand Journal of Botany published a similar study in which researchers and scientists analysed the ex situ conservation of Bartlett's rātā individuals at Ōtari-Wilton's Bush.

[b] In their 2021 analyses, hand-pollination of Bartlett's rātā individuals produced seeds with generally low germination rates; this biological finding is consistent with other species in the family Myrtaceae, such as pōhutukawa (M. excelsa) and mānuka (Leptospermum scoparium).

The research article also revealed that the flower development of Bartlett's rātā is characterised by dichogamy, which is a method to prevent self-pollination by having stigma receptivity and release of pollen occur sequentially, i.e., not at the same time.

[34][33] The endemic liverwort species Frullania wairua and Siphonolejeunea raharaha-nehemiae, both at risk of extinction, are known to be hosted by Bartlett's rātā.

[3] A DNA profiling test of Bartlett's rātā individuals was conducted in 2015, the Department of Conservation were unaware that three of the five genotypes required to grow genetically suitable trees were located on the tribal territories of the Ngāti Kurī and Te Aupōuri iwi.

New Zealand botanist and science advisor Peter de Lange stated that without intervention "the future was bleak" for Bartlett's rātā.

[42] Bartlett's rātā's habitat favours dense lowland forests; the plant usually germinates and begins life as an epiphyte, specimens have been observed growing on pūriri (Vitex lucens), rewarewa (Knightia excelsa), taraire (Beilschmiedia tarairi), and tree ferns (Cyathea).

[47] The decline of Bartlett's rātā is attributed to land use changes following human settlement and the introduction of common brushtail possums,[40][45] an invasive species in New Zealand.

Although the forests in Northland are gradually recovering, the population of Bartlett's rātā remains low and is scattered between three known locations near Piwhane / Spirits Bay.

[51] Unless immediate conservation measures are taken, Bartlett's rātā has a high chance of becoming extinct due to its ongoing decline, small population size, and reproductive failure.

In 2020, the iwi started a planting programme supervised by Manaaki Whenua – Landcare Research with the aim of increasing and protecting the number of Bartlett's rātā trees remaining in the wild.