Myrsine argentea is a shrub or small tree, endemic to Aotearoa / New Zealand where it occurs on Te Wai Pounamu / South Island, Wakamarama Range, Mt Burnett. The population is suspected to be fewer than 5,000 mature individuals, occurring in one location with an area of occupancy of less than 10 km². This location is being mined for dolomite, although mining operation is slowing down and regeneration of the species is occurring. However, due to mining, invasive weeds, browsing animals and fire risk there is a continuing decline in the habitat. It is assessed as Critically Endangered.

This species is endemic to Aotearoa / New Zealand where it occurs on Te Wai Pounamu / South Island, Wakamarama Range, Mt Burnett. Distribution map is generalised.

No accurate population assessment has been undertaken. It is estimated that there are ≤5,000 mature plants confined to the summit peaks of Mt Burnett, an area ≤1,000 ha of dolomitic marble, and dolomite karst (Heenan and de Lange 1998, de Lange et al. 2010, de Lange 2023). The sole known habitat is being mined for dolomite and is subjected to weed invasion blown onto the peak from nearby farmland as well as spread along mine roads.

Myrsine argentea is a shrub or small tree (up to 9 m tall) occupying a narrow band of dolomite and dolomitic marble karst / karrenfield exposed near the summit tops of Mt Burnett (641 m asl). At this location it grows in forest and in shrubland / flaxland on exposed outcrops, rubble slopes, mine pits and along roadsides cut into the summit peak (Heenan and de Lange 1998, de Lange 2023). In the forested habitat Myrsine argentea is a scarce component of the understory within Nothofagus menziesii / Metrosideros umbellata forest. The species is more common as part of the shrubland colonising exposed dolomite and dolomite marble outcrops, where plants grow directly in cracks on rock or within pockets of typic rendzic melanic soil overlying these. Co-associates in these habitats include Carex dolomitica, Phormium cookianum subsp. hookeri (=P. colensoi, POWO 2023), Brachyglottis laxifolia, Coprosma linariifolia, C. obconica, Gingidia haematitica, Hoheria ovata (=H. sexstylosa var. ovata, POWO 2023), Libertia mooreae, Senecio glaucophyllus and Melicytus obovatus (Heenan and de Lange 1998). The habitat preferences of the species suggest a preference for open / exposed habitats, and most regeneration is noted in recently disturbed ground. Plants are dioecious, females producing copious white fleshy fruits which are bird and probably gecko / skink dispersed.

The sole known habitat, Mt Burnett, as the only known economically viable deposit of dolomite is, despite its location within Kahurangi National Park is being mined (Heenan and de Lange 1998, de Lange 2023). Mining constitutes the main threat to this species, the associated endemic Carex dolomitica and a range of other nationally threatened plants and animals with strong holds on Mt Burnett (Heenan and de Lange 1998, de Lange 2023). Mining as a threat is predicted to eliminate between 10–30% of the remaining population in the next 10 years (de Lange et al. 2018). Mining is however being phased out, and despite the immediate loss of established populations, sufficient trees remain in adjacent forest to allow seeding back into the mine rubble. In these places there is healthy regeneration of Myrsine. Other threats include feral goat (Capra hircus) browsing, and competition from Mexican Daisy (Erigeron karvinskianus), gorse (Ulex europaeus), Pampas grass (Cortaderia selloana) and other exotic grasses which have spread up the mountain along roadsides and through seed blown up from nearby farmland. 

Although the Wakamarama Range is frequently covered in cloud and rain fall is heavy there, dry spells with an increased likelihood of fire can occur.

Myrsine argentea is assessed as ‘At Risk / Declining’ (de Lange et al. 2018).

This species is very uncommon in cultivation in Aotearoa / New Zealand.

Myrsine argentea despite ongoing loss of some key habitat from dolomite mining is able to regenerate from seed sources in the forested portions of the summit slopes, and from vegetation remnants left on less accessible outcrops and slopes. The population of the species is believed to be ≤5,000 within an area of <1,000 ha, the main declines of the species happened during the initial phases of mining (Heenan and de Lange 1998) though the extent of loss if unknown. Mining has slowed as opposition to the mining operation has increased. Much of the mining operation has now ceased, in part because of a down turn in the need for dolomite and a re-evaluation of the economics of continuing the venture. The most concerning threats to the species (and other important biota of Mt Burnett) is now browsing animals – which need regular control, and weeds which are being managed by the New Zealand Department of Conservation. During dry spells fire is a potential problem but because Mt Burnett is a conspicuous landmark visible to small settlements with a fire service nearby, less of an issue than in more remote areas.