Calothamnus Quadrifidus
Calothamnus quadrifidus R.Br.
Calothamnus quadrifidus, the one-sided bottlebrush, is a tough, versatile Western Australian native shrub bearing dramatic clusters of deep red claw-like flowers arranged uniquely along only one side of each stem. Hardy, bird-attracting, and visually striking, it is one of the best-known and most widely grown members of its genus.
Myrtaceae
Spring to early summer (most abundant); some flowering may occur at other times of the year
Symbolism & Meanings
Key Meanings
Perfect For
Color Meanings
Similar flowers: gladioluss and banksias also share similar meanings.
Cultural Significance
Calothamnus quadrifidus was first formally described in 1812 by the celebrated Scottish botanist Robert Brown, based on a specimen collected at Lucky Bay near Esperance during the historic Investigator expedition with Captain Matthew Flinders in 1802. The description was published in Curtis's Botanical Magazine (edited by John Sims), one of the most prestigious and long-running horticultural journals in the world. The genus name Calothamnus is derived from the Greek words kalos meaning "beautiful" and thamnos meaning "a shrub" or "a bush," making its meaning simply "beautiful shrub." The species name quadrifidus comes from the Latin quadrifidus meaning "split into four parts," referring to the four-part flower structure. In 2014, researchers proposed on the basis of DNA evidence that all Calothamnus species be transferred to the genus Melaleuca, though this reclassification remains contested and has not been universally adopted. An ecological study of Calothamnus quadrifidus has specifically examined competition between introduced honeybees and native honeyeaters for its nectar, finding that while honeybees consume a larger total volume of nectar due to their numbers, honeyeaters remain more important for pollen dispersal and thus plant reproduction.Shop Our Floral Collection
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Physical Characteristics
Natural Habitat
Growing Guide
Sunlight
Full sun; performs best with at least 6 hours of direct sunlight daily
Water
Drought-tolerant once established; prefers dry summers; tolerates both well-drained and moderately moist soils; avoid prolonged waterlogging
Soil
Sandy, Loamy, Clay loam, Poor soil, Well-drained to moderately well-drained, Adaptable to most soil types
Expert Growing Tips
Plant in well-drained soil in full sun; one of the most soil-adaptable of all Western Australian native shrubs
Highly drought-tolerant and frost-hardy once established; tolerates temperatures down to approximately -7 degrees Celsius
Tolerates coastal exposure, salt spray, sandy soils, clay soils, and moderate humidity, making it more broadly adaptable than most WA natives
Prune lightly after flowering to maintain a compact, tidy shape and encourage the following season's flower production; the plant flowers on old stems so avoid cutting back to bare wood
Avoid high-phosphorus fertilisers; native-specific low-phosphorus fertilisers may be used sparingly
Propagate from seed (sow after the risk of frost) or from semi-hardwood cuttings; seed germination is more reliable than in many Myrtaceae
Uses & Benefits
Ornamental Uses
- Feature shrub for bold spring colour
- Bird-attracting garden plant; a major nectar source for honeyeaters
- Informal screening hedge or windbreak
- Erosion control on slopes and banks due to strong root system
- Cut flower for arrangements (unusual one-sided flower clusters are highly distinctive)
- Honey-producing plant of significant value to beekeeping
Traditional Uses
- Indigenous Australians in Western Australia traditionally used Calothamnus quadrifidus to treat coughs, colds, and fever
- Phytotherapeutic research has identified phenolic acids and flavonoids in the aerial parts of the plant, confirming biological activity consistent with traditional uses
Disclaimer: Information provided is for educational purposes only. Consult healthcare professionals before using any plant medicinally.
Further Reading
Frequently Asked Questions about the Calothamnus Quadrifidus
Why is calothamnus quadrifidus called one-sided bottlebrush?
It is called the one-sided bottlebrush because its red flower clusters are arranged exclusively on one side of each stem, rather than surrounding the stem in a full cylinder as in true bottlebrushes (Melaleuca). This creates a distinctive and unusual appearance that immediately distinguishes it from related plants.
Is calothamnus quadrifidus the same as melaleuca?
They are closely related and in the same family (Myrtaceae). In 2014, researchers proposed transferring all Calothamnus species into Melaleuca based on DNA evidence, but this reclassification remains contested and has not been universally adopted. Calothamnus differs from Melaleuca most noticeably in the arrangement of its stamens, which are in four separate claw-like bundles rather than united in five groups.
Is calothamnus quadrifidus hard to grow?
No, it is one of the most adaptable and low-maintenance of all Western Australian native plants. It tolerates a wide range of soil types, drought, coastal exposure, salt spray, and frosts down to approximately -7 degrees Celsius. It even copes with some humidity, which makes it more broadly suitable than most WA natives.
What birds does calothamnus quadrifidus attract?
The abundant nectar of its flowers is an important food source for honeyeaters, particularly the Brown Honeyeater and White-cheeked Honeyeater in its native Western Australia. Scientific research has specifically studied competition between native honeyeaters and introduced honeybees for the nectar of this species, confirming honeyeaters are the more important pollinators despite bees consuming more nectar overall.
How do you prune calothamnus quadrifidus?
Prune lightly after the main spring flowering, trimming back spent flowering stems. The plant flowers on old wood, so avoid cutting back into bare stems without leaves. Regular light pruning maintains a compact shape and encourages more prolific flowering the following season. Harvesting cut flower branches is an effective way to prune while getting the most from the display.
Available Colors
Quick Facts
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