These notes are adapted from a Powerpoint display that was to be delivered at an ANBG guide’s meeting in June. Alas, times have changed, and so I have done my best to change to a Word document. This is not ideal, and the pages have some rather strange formatting. Please bear with me, as I hope one day to take anyone who is interested on a stroll through the Gardens to look at the colourful, aromatic world of the Australian Rutaceae members.

Note on References

Many of these observations come from my years of working in the horticulture industry. These include 12 years at Queanbeyan Retail Nursery and 25 years as a horticulture trainer at CIT. Prior to that I worked in the Northern Territory for the Conservation Commission, Berrima Experimental Farm and Tropicus Wholesale Nursery. Therefore the notes below are more of ‘gardener’s musings’, rather than an academic undertaking.

There are a couple of books that I often turn to, and these are listed at the end. When the photos were originally uploaded to the Powerpoint display, I did copy the source websites, so hopefully these still show through.

My approach is towards the practical and casual. Happy gardening and happy plant-pondering!

Regards, Jane

2/5/2020

In Botanical nomenclature the Family was usually given its name after a prominent genus found within the group. In the case of Rutaceae, that genus is a northern hemisphere group of herbaceous plants, Ruta, commonly called Rue. Those of you with herb gardens may know Rue, as it is a well-known insect repellent and old-fashioned medicinal plant from classical times.

There are several other exotic genera within the Family, many of which are common garden plants.

Correa alba is common in many sites of the Australian National Botanic Gardens. There is clump of them near the base of steps, adjacent to the Friend’s Flowform Cascade to South of Visitors Information Centre (VIC) Fantastic as a drought hardy, salt-tolerant screen or hedge, with bonus of attracting native honey - eating birds.

C.’ Dusky Bells’ is one of the earliest and most common cultivars used around the local nursery industry. Found in profusion at public places like the

Sculpture Garden at the National Gallery of Australia, it is a great space filler. Works well under dry shade.

Correa reflexa is a local species and has many varied forms. It can be seen growing in wild up at Molonglo Gorge, and is a very tough plant. There is a low-growing form of it in the Easy Care Garden-section 339- which is in front of the Circular Toilet block (near Brittle Gum Lawn)

There are often Brown Boronia specimens growing in display pots near the Visitors Information Centre (VIC) in Spring. The myth is that some people can smell the aroma, and some cant (I can’t)! Author May Gibbs created lovely ‘Boronia Blossom’ characters in her Snugglepot and Cuddlepie stories.

If you want to grow Boronias, is often suggested that they are grown in pots, as they require perfect drainage and are prone to root diseases. There are now a wealth of Cultivars (CVs) to choose from.

The Sydney Boronia may be a good one to try in the home garden (given frost protection), found in Sandstone regions, check out the Sydney Region Gully in Spring! Despite its common name, it is found as far south as coastal Victoria and in Southern Tablelands and central western slopes NSW.

Note : There is a rare Boronia repanda next to the Banks Walk, which is a “species under threat”.

These were formerly known as Eriostemon and a lot of gardeners still use this name. The common name Waxflower should not be confused with Geraldton Wax, which is Chamaelaucium species from Western Australia (WA), and not related at all!

There is a lovely CV called ‘Profusion’ growing in the Easy Care Garden Section 339. They flower prolifically in Spring and attract native insects like hoverflies.

Many species are hardy and Philotheca myoporoides is often used locally in public plantings, as they tolerate frost, sun and shade. It is also known as Native Daphne and comes in Long leaved and Short leaved forms.

It can be seen in the Sydney Region Gully.

Crowea is only a small Genus, but the forms that are seen around the Gardens put on a fantastic display in Autumn. There are several Crowea exalata growing at the base of the steps to the carpark from the VIC, near the Friends’ Flowform Cascades.

Crowea saligna, which is a broader leaved species, has been developed into several cultivars, ‘Festival’ being one of most common. There is even a white one!

They are frost hardy and real show-stoppers during the colder months of autumn. C.saligna can be seen at the bottom left of steps going up to The Rock Garden, next to a prolific bush of Correa ‘Ivory Bells’.

Phebalium Genus is endemic to Australia and consists of 29 species.

Phebalium squamulosum (Scaly Phebalium) puts on a great show of yellow star flowers in Spring. There are some large ones on the perimeter of the carpark closest to VIC. I have planted several in pots and am looking forward to seeing how they survive winter, as I live in a frost hollow! It has several (as many as 10) sub-species and can be quite variable in form, growing up to 2 metres. At least 4 sub species are found around Sydney.

Zieria species are a distinctive group as they have 3-foliate leaves, and often smell quite pungent. According to Wikipedia there are about 60 species and the genus is also endemic to Australia.

The Tree Zieria Z.arborescens is also known as Stinkwood, for obvious reasons (crush the leaves and see)! It can be seen in the Sydney Region Gully and makes a lovely shady screen in a cool protected spot.

Citrus australasica or Finger Lime is perhaps the best known native bush fruit tree or shrub. This prickly member of the Rutaceae Family is a large shrub to small tree from NE NSW and South Eastern Qld. It naturally occurs as an understorey plant and requires protection in Canberra.

Several specimens are growing on the left of the upper Rainforest Gully board walk, and in a large tub in front of Circular toilet block at Easy care garden Section 339.

According to the ANBG website, there are currently 5 registered cultivars and the fruits are prized by chefs. As they can take up to 15 years to fruit from seed, so growing them from cuttings or purchasing a Cultivated Variety will speed up production.

Unlike other citrus, little fertilizer is required for maintenance, if the soil is mildly acidic, free draining and with high levels of organic matter. Giving them a light prune after it has finished fruiting will improve yield. Fruiting is in winter, as for exotic citrus varieties.

The Chef’s Cap Correa was one of my favourites to teach to horticulture students. It is a relatively unimposing plant with its green pendulous flowers and students had several Correa species to identify in tests. I would ask them to squeeze and smell the leaf- “what does it smell like?’- “Juicy Fruit Gum” they would often shout with-and never forget the plant!

So in conclusion, may I commend the Rutaceae family as not only important ecological plants, but also fantastic garden specimens. There is a Rutaceae in flower at just about any time of the year. For example:

Autumn-winter- Correa, Crowea and Citrus Spring – Summer- Philotheca, Boronia, Phebalium, Zieria

Due to the ease of hybridisation and growing from cuttings, Correa spp. in particular have been much developed and improved for garden use. Who could go past our famous C.‘Canberra Bells’, developed for the Centenary of Canberra in 2013? These can be seen growing along the side of Section 339 Easy care garden, and along the edge of the road between the Eucalyptus Lawn and the Sydney region Gully.

References:

Fairley, Alan & Moore, Philip (1989) Native Plants of the Sydney District Kangaroo Press

Robinson, Les (1991) Field Guide to Native Plants of Sydney Kangaroo Press

anbg.gov.au

ala.org.au

Wikipedia.org