Isopogon dawsonii

Nepean Conebush

Family: Proteaceae

A shrub to 6 metres high but is usually up to 3 metres tall, and to 3 metres wide. It does not develop a lignotuber.

It is found growing naturally on the central coast, central tablelands and central western slopes regions of NSW, in areas such as the Goulburn River Valley, Hawkesbury-Nepean River Valley and down to around Lithgow and western Sydney (start of the Blue Mountains).

It is found in dry sclerophyll forest and on cliff edges in heathland, growing in usually very well drained, either gravelly or sandy soils.

The leaves are up to 13 cm long, with most of the leaf consisting of a linear segment and then the top third of the leaf divided into several forked segments (pinnatisect appearance), mid grey/green to deep green
in colour. The new growth can be bronze to red, making it attractive when not in flower.

The inflorescences of Isopogon are typically globe-shaped terminal heads, consisting of many bright yellow flowers occur in late spring and early summer. The flower clusters are around 45 mm in diameter, conspicuously displayed on the ends of the branches and subtended by small simple or divided leaves.

Being a Proteaceae genus, the flowers are similar to that of other genera with flowers having 4 tepals, 4 stamens and 1 carpel. Each head might have 50 – 100 flowers. The inflorescences can be produced in large-number, giving a nice display in late winter to summer.

The individual flowers are about 1 mm long and are creamy-yellow, silver- or grey-white. The styles turn to deeper orange during flowering.

The fruiting “cone” is globose, to 3 cm in diameter. The nuts are to 4 mm long and covered in hairs.

In the garden

Deserves to be more widely grown as it is relative hardy once established. It can be grown successfully in gardens (see ANPSA study group newsletter in references).

It reportedly likes a well-drained acidic soil (sandy) but can tolerate heavier soils. Grow in full sun to light shade for best results. It will tolerate light pruning. Tolerant of light to moderate frosts once established. It can grow quickly if the position is right.

Suitable to open gardens on slopes and larger beds.

Propagation

Propagation from seed works well as well as cuttings of firm new growth.

Other information

Following bushfires, this plant regenerates from seed.

Isopogon – from the Greek words Isos (ίσος) meaning ‘equal’ and -pogon (πώγων) meaning ‘beard’, referring to the equal-length hairs on the fruits (nuts) of some species.
dawsonii – named in Honour of James Dawson (1854-1937), who was a 19th Century surveyor, who lived in Kandos for 50 years and helped established the town, and was a botanical collector, resulting in several species being named after him.

Not considered at risk in the wild.

http://anpsa.org.au/iso-petSG/iso-pet7.pdf
https://apps.lucidcentral.org/plants_se_nsw/text/entities/isopogon_dawsonii.htm
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Isopogon~dawsonii

By Jeff Howes