Isopogon and Petrophile

 

국표에 없다.

 

 

 

Isopogon and Petrophile

David Lightfoot

Isopogon and Petrophile are two closely related genera in the Protea family (Proteaceae). Both are endemic to Australia and both have their greatest diversity in south Western Australia. Although some members of both genera have been cultivated for many years, there is still much to be learned and this is the aim of the Isopogon and Petrophile Study Group, of which David is the leader. For further information on the Study Group, contact David at isopogons@iprimus.com.au

Isopogon

The name of the genus derives from the Greek isos - equal and pogon - a beard. This is thought to refer to the hairs surrounding the fruit.

Isopogon is an endemic genus. Some species (e.g. I.buxifolius) seem to be closely related to South African Proteaceae and may be revised in the future after DNA work has been completed. There are 35 currently recognised species with 27 of these found in the south west of the country. The eastern varieties span the coast from southern Queensland into South Australia and the eastern Bass Strait islands. They don't make it to the Tasmanian "mainland".

Isopogons are mainly small to medium sized shrubs with a number being prostrate or near so. They are characterised by semi globular or ovoid inflorescences, packed with small flowers, which range in colour from cream to yellow in the east, with pink, and mauve added in the west. The flower heads are usually terminal and showy but in some species are axillary. Thus many have potential as cut flower varieties. The shape has lead to the common names of drumsticks and coneflowers. The foliage is extremely variable throughout the genus ranging from simple narrow to ovate, through to deeply and intricately divided. The new growth is often red and contributes to the horticultural desirability of some taxa.

The fruiting cone is held for some time before breaking up with loss of the external bracts. It is the loss of these scales and the disintegration of the fruiting cone that distinguishes Isopogon from Petrophile (where the scales are retained). In general isopogons grow close to the coast and when they do appear inland they are not found in arid areas. They are found in heath and dry sclerophyll woodlands, generally on very well drained nutrient poor, sandy soil.

Isopogon species have been cultivated since 1791 but are still relatively rare in today's gardens.

 

Petrophile

The name of the genus derives from the Greek petra - a rock and phileo - to love (philos, beloved). The first species described were discovered in the Sydney region in the sandstone country and were therefore thought to be 'Rock Loving'.

Like Isopogon, Petrophile is an endemic genus. At the moment, there are 53 recognised species with 47 of them originating in the south west of Western Australia. One species is confined to Kangaroo Island, off South Australia, and 5 species are found in New South Wales and south eastern Queensland. There are a number of as yet unnamed taxa in Western Australia, and the Herbarium in Perth is currently working on descriptions of these.

Most of the western species are found growing in deep sand, and in full sun within the sandplain heaths. Although some are found in gravely soils, it is almost universally extremely well drained. The eastern species live more up to their generic name and are found predominantly in sandstone country, in dry sclerophyll forest or heath. Again they grow in lots of sun, often occurring where other vegetation is thin.

The western species are found in temperate and semi arid climatic zones. They can be found reasonably close to the coast throughout the South Western botanical zone. The eastern species are found close to the Great Dividing Range and down to the coast.

Isopogon and Petrophile (anpsa.org.au)

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