Banksia vincentia

Vincentia Banksia

Family: Proteaceae

A very rare banksia, only recently found in the wild, which grows to only 1 m tall but can spread to 2 m wide, bearing a lignotuber. It has mostly prostrate stems which curve up (decumbent) at terminals.

It is restricted to a small area near Vincentia at Jervis Bay in NSW. Less than 20 plants were originally found in the wild. It is a critically endangered species at State and Commonwealth level and is considered Australia’s rarest banksia. It grows in coastal sclerophyllous shrubland on sandy-clay soils over sandstone.

The leaves are alternate, narrowly oblong/obovate, to about 5 cm long and only 0.7 cm wide, green to dark green in colour with only minimal teeth (1-6), usually near the apex. Lower surface is paler and hairy.

The inflorescences of banksias are generally referred to as spikes or a spike-like structure which consists of fused racemes of paired flowers (hence it gets referred to as a conflorescence). There can be 100s of flowers in each spike. The flowers of banksias have 4 tepals (petals or sepals) in a tubular formation, 4 anthers hidden inside and an elongated carpel (female part) where the style and extends outwards forming the edge of the spike (somewhat similar to individual grevillea and hakea flowers).

In this species, the spikes are generally to 17 cm long and about 8 cm wide, with each flower thin but up to 4 cm long, orange to yellow-orange in colour. The styles (female part of flower) can be a vivid dark red to purple-black and hooked at the apex (very similar to B. spinulosa).

The spike then turns into a cone-like structure of follicles; a fruit which splits open on one side. Each follicle has one or two winged seeds which is actually a fruit in itself called a samara. The follicles can take a long time to mature and open, usually needing a fire. Each “cone” can produce a fair amount of seed with this species having up to 100 follicles per “cone”, each up to 25 mm long.

In this species, flowers are produced but fruits are rarely produced.

In the garden

Not readily available for cultivation currently. It is currently being propagated as part of the NSW Saving our Species Project. However, if this species is desired to be cultivated, growers can pick B. spinulosa or B. marginata and get a very similar effect (see these profiles). It may be able to be sourced from nurseries in the areas where it grows eventually. The cultivars in the references below may still be relevant.

If this species if ever available for cultivation (just like the Wollemi Pine) the following can likely be applied:

May grow to 1 m tall in a garden (although this will take time) so allow some space, but can grow to 2 m wide – a feature which may be desirable. Very suitable for coastal gardens. Plant in a well-drained soil for best results – sandy to loam. Most banksias thrive if planted on a slight slope.

Do not apply a high phosphorus fertiliser as Proteaceae are generally sensitive.

Prune after flowering or harvest cut flowers. Can be trained into a denser shape with periodic pruning.

Some cultivars have the potential to produce many spikes, creating a dramatic effect.

Susceptible to Phytophthora and any other root rotting fungus.

Propagation

Propagation is currently done from cuttings mainly.

Other information

This species has historically been a part of the Banksia spinulosa complex with a range of forms and variety exhibited. A PhD study was undertaken by Margaret Stimpson who raised the variety ranks of the complex to separate species:
Banksia collina
– Banksia cunninghamii
– Banksia neoanglica
– Banksia vincentia

Intermediates between all of these taxa still occur.
B. vincentia is differentiated from B. spinulosa by the prostrate and short habit, the mostly entire leaf margins and generally wider leaves with dense hairs.

Likely regenerates mainly from lignotuber, based on field observations, after fire.

Banksia – named in honour of Joseph Banks (1743 – 1820), famous naturalist and botanist on the Endeavour and other expeditions, and President of the Royal Society for over 40 years. The genus was named in his honour by Linnaeus filius (Carl von Lynne – the Younger, son of the famous Carl von Lynne (Linneaus)).

vincentia – named for Vincentia, the location where it grows at Jervis Bay, NSW

It is a critically endangered species at State and Commonwealth level and is considered Australia’s rarest banksia.

https://www.biotaxa.org/Phytotaxa/article/view/phytotaxa.163.5.3 https://www.environment.nsw.gov.au/news/banksia-vincentia

https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Banksia~vincentia

By Dan Clarke