Callistemon megalongensis is a shrub growing to around 4.5 m tall with soft, flaking or peeling bark.
It is similar to Callistemon citrinus which occurs in the same area and is difficult to distinguish from it, except when in flower.
This shrub is endemic to NSW and restricted naturally to the Megalong Valley in the Blue Mountains of NSW. It is found in shrubby swamp communities near streams.
It is a listed threatened species.
Callistemon spp. have simple and alternate to spiral leaves. In this species, leaves are to 55 mm long and only 5 mm wide.
Callistemon inflorescences are generally referred to as spikes, consisting of staminate flowers with reduced petals (the stamens have basically taken over the role of the petals). In this species, spikes are to 40 mm in diameter with 25 to 60 individual flowers. Some flowers can have up to 50 stamens. The filaments of the stamens are pink with a dark red anther. Flowering occurs in November and December.
Capsules are to 6 mm diameter, arranged in the same spike-like structure along branches. Callistemon spp. have the condition where leafy growth extends beyond the flower/fruiting spike.
Not much is currently known about the cultivation of this species. This is likely due to its threatened species listing and the fact that it was relatively recently discovered and described. It has being propagated for conservation purposes (see references below). It may be more readily propagated and cultivated in the future.
It grows in swampy conditions and so may need some soil moisture to do well. Best grown in a sunny to part shade spot with reliable water. Prune after flowering to encourage a denser plant and more flowers next season. Plants may be hard to source commercially but check with council and other local native nurseries.
Propagation is from both seed and cuttings.
Some herbaria are calling this species Melaleuca megalongensis based on a reclassification by the Late Lynley Craven (1945-2014) where all species of Callistemon were re-classified as Melaleuca spp. The National Herbarium of NSW currently still retains the former classification.
Regenerates after fire from epicormic and basal shoots as well as from the seedbank.
Callistemon – From the Ancient Greek – Callos (κάλλος) – meaning “beautiful” (which is changed to κάλλη to describe a noun) and and stêma (στῆμα) meaning “stamen”, referring to the very showy staminate flowers of the bottle-brush inflorescences.
megalongensis – Latin – referrring to the Megalong Valley where the species is found, south of Blackheath in the Blue Mountains – west of Sydney.
This species is listed as being threatened with extinction, with the category of critically engandered, at both the State and Commonwealth level.
NSW Flora Online (PlantNET) – Callistemon megalongensis profile page
NSW Office of Environment and Heritage – Threatened Species Profiles – Callistemon megalongensis profile page https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10517
Blue Mountains Gazette – Saving the Callistemon megalongensis https://www.bluemountainsgazette.com.au/story/6368135/young-landcare-champions-from-megalong/