Callistemon shiressii is an uncommon shrub or small tree, to 12 metres tall.
It occurrs in and between the Sydney and Hunter Valley areas in NSW, and is also found between Gosford and Wyong (central coast, north coast and central western slopes subdivisions).
It grows on shale ridges in moist eucalypt forest and rainforest as well as along riverbanks.
Callistemon spp. have simple and alternate leaves, often arranged in a spiral. In this species, the leaves are arranged alternately, to 7 cm long, and to 1 cm wide, and end in a sharp point.
In Callistemon species, flowers are usually arranged in spikes (the “bottlebrush”) which are produced at the terminals but which the stem then grows past, into a leafy shoot. Flowers have five small circular sepals and five circular petals which persist on the flowers.
Like many other Myrtaceae genera, the flowers are conspicuously staminate with each flower having many stamens surrounding one carpel. The stamens are typically free although may be fused at the basal parts (a generally useful identifying feature for the genus to distinguish it from Melaleuca). The pedicels of the flowers are very short. In this species, the spikes are cream or greenish-cream and are arranged at the end of branches, to 20 mm in diameter and to 50 mm long with 5 to 25 individual staminate flowers, each about 5 mm in diameter. Flowering occurs from September to January
Fruits are are woody capsules, to about 5 mm long and wide.
Hardy, drought tolerant plant forming a neat compact shrub to tree size and grows over a wide range of soils. Flowers best in full sun.
The plant responds to annual fertilising after flowering and may be pruned severely if necessary. Prune 2/3rds off spent flower to encourage prolific growth and reduce woody stems.
Flowers are attractive to birds and insects.
Propagation is easy from both seed and cuttings.
The genus Callistemon has been subject to recent taxonomic revision with early and recent botanists including Ferdinand von Mueller and Lyndley Craven (deceased in 2014) proposing to ‘lump’ the genus into Melaleuca and others. Craven et al. (2014) published new species combinations which included the renaming of all Callistemon species to Melaleuca, based on evolutionary relationships and DNA evidence and other features.
Currently, the NSW Herbarium advises that the Callistemon genus can still be used. There are currently about 30 species of Callistemon, which are found in all states of Australia as well as New Caledonia. About 28 are endemic to Australia. NSW currently recognises 24 species. New species have been described in the last 20 years.
May regenerate from seed after fire. Most bottlebrushes exhibit reshooting from branch stem buds and basal areas of stems/trunks after fire or pruning.
Callistemon – From the Ancient Greek – Kallos (κάλλος) – meaning “beautiful” (which is changed to κάλλη to describe a noun) and stêma (στῆμα) meaning “stamen”, referring to the very showy staminate flowers of the bottle-brush inflorescences.
shiressii… honours David William Campbell Shiress (1862-1944) who, with William Blakely, collected the type specimen.
This species is not known to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Callistemon shiressii profile page
Wikipedia – Melaleuca shiressii profile page https://en.wikipedia.org/wiki/Melaleuca_shiressii
Hawkesbury City Council – Callistemon shiressii factsheet https://www.hawkesbury.nsw.gov.au/__data/assets/pdf_file/0004/131629/Callistemon-shiressii.pdf
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.