Tibouchina cultivars are very popular in South East Queensland, 'Alstonville' joining Jacaranda and Poinciana as signature species in gardens of this region.
As with so many plants which are transported and cultivated all over the world, there's quite a bit of confusion over the identity of varieties, and their correct names. Many of the online references are in Portugese which makes it difficult for an English speaker to invesigate Brazillian sources of information.
This page is a work in progress, and it's hoped to be able to bring you more information and illustrations in future updates. In the meantime, hopefully you'll find something useful here.
Links to relevant webpages on other sites are given throughout the text. See the bottom of the page for details of printed books and printed jounal articles referred to in the text, and more links.
Tibouchinas originate in South America. The word itself is derived from the native name in the Guiana region (the countries to the north of Brazil) (Hazelwood, 1968; Harrison, 1967). Tibouchinas are cultivated widely in Brazil. T. granulosa is called Quaresmeira. T. lepidota is called Sietecueros.
In older Australian and New Zealand literature, Tibouchina is also referred to by the older name of Lasiandra. The most commonly cited species prior to the 1980s is the plant variously referred to as Lasiandra macrantha, Lasiandra semidecandra, Tibouchina semidecandra, Tibouchina semi-decandra and later, Tibouchina urvilleana.
The most common species cultivated in the USA is apparently still T. urvilleana
, although it is not commonly available in the Queensland marketplace anymore. T. urvilleana
and some other members of the genus are weeds (or potenially weedy) in some areas (for example, see: Hawaii's Most Invasive Horticultural Plants
'Grandiflora' was a popular variety, having larger flowers than the species. (You may sometimes see reference to a species called Tibouchina grandiflora. This is a synonym of Tibouchina heteromalla).
A cultivar of Australian origin which is also frequently mentioned is 'Edwardsii'. Victorian nurseryman Edward Edwards crossed 'Grandiflora' and the species to obtain flowers of a deeper richer colour. 'Edwardsii robusta' was another variety selected for large flowers and vigourous growth. (Herbert, 1958; Harrison, 1967; Hazelwood, 1968)
Although 'Edwardsii' and 'Grandiflora' may have had somewhat more dwarf and compact growth than the species (opinions on the relative merits of each vary somewhat between authors), the "Lasiandras" generally had a poor reputation as plants with straggly growth habit and a need for frequent pruning.
The Tibouchina Revolution in Australia
This began when Australian nurserymen made several garden-worthy selections from various seed imported from Brazil in the 1960s. Particularly prominent in the Tibouchina story are the Dunstan family, who selected and marketed 'Alstonville' and several others. The superior characteristics of the new plants eventually won over gardeners. Today, Tibouchinas constitute one of the most significant groups of flowering shrubs/small trees in gardens of this region.
Students of horticulture interested in researching the history of 'Alstonville' and other Australian cultivars of the period should consult Dunstan (1982), Burke (1984) and Lake (1996). (See list of references at the bottom of this page).
Modern Tibouchina Cultivars
The following refers to the more commonly grown cultivars commercially available in Australia. More information will be added as it comes to hand.
Tibouchina lepidota 'Alstonville'
By far the most popular Tibouchina for Brisbane gardens so far, 'Alstonville' has rich purple flowers and can be ealiy spotted all over the city at flowering time.
Classed as a shrub by some, it can be trained as a small tree with appropriate pruning. Its small and controllable size has no doubt contributed to its popularity in modern gardens, where there is no longer space for grand tropical flowering trees like poinciana.
Although it can produce some flowers in spring, 'Alstonville' provides a burst of colour in late summer/early autumn. Its namesake Alstonville (NSW), the town near which this plant was developed, has a Tibouchina festival every year in March when the trees are putting on their best display.
'Alstonville variegata' is a variegated leaf form. If anyone is still producing this cultivar commercially, please get in touch.
This cultivar has been very popular too, but in contrast to 'Alstonville' it is a dwarf shrub, suitable for a garden bed or container.
Tibouchina granulosa 'Kathleen'
This cultivar has pink flowers (The original species T. granulosa has purple flowers), and will grow into a tree if left unpruned.
One of the cultivars from the Dunstan family of the 'Alstonville' period, this shrub's flowers open white and darken to through pink with age.
Hazelwood (1968) describes a Brazilian species called T. bicolor, the flowers of which start white and turn to purple as they age. More recent publications refer to a T. mutabilis which has similar characterstics. Perhaps 'Noeline' is a cultivar or maybe just the regular species.
A number of Tibouchinas have been introduced into the marketplace in Australia over the years, but have failed to gain as much popularity as those above. These include:
Tibouchina holosericea 'Alba' (syn. Tibouchina clavata 'Alba') - promoted in Australia as Tibouchina 'Elsa' (Burke, 1984)
Tibouchina laxa - promoted in Australia as Tibouchina 'Sky Lab' (Burke, 1984)
Tibouchina 'Carol Lyn', also sold as Jazzie
A recent trend had been for cultivars suitable for smaller gardens and containers. 'Groovy Baby'PBR (Plant Breeders Rights Application, IP Australia in .doc format) is one that has received a lot of attention and is being promoted for its compact habit, long flowering season and relative cold tolerance. It remains to be seen whether this and other new cultivars can stand the test of time to become garden classics.
In the literature, gardeners are generally advised to plant Tibouchinas in well drained, acidic soils and to supply plenty of water and fertiliser. However, Tibouchinas are seen all over Brisbane in situations where soils are undoubtedly less than ideal and where they're unlikely to be receiving any supplemental water or fertiliser after establishment. In this region, therefore, they can be considered relatively tough, trouble-free plants for average garden conditions.
Of course, they are more likely to perform at their best with a little attention. They are widely believed to like an acid soil so this should be kept in mind when considering fertilisers, potting mixes and soil amendments.
The best time for major pruning in frost-free climates is immediately after flowering (the main flowering period for Tibouchina in Queensland being autumn).
Uses in the Garden
As indicated above, Tibouchinas are available in a range of growth forms, so you can select a variety to suit your needs whether it is a small flowering tree, a shrub or groundcover. You can also manipulate the form to some extent depending on how you prune. The very dwarf cultivars are suitable for growing in containers.
In terms of style, although the tibouchinas may be classed as "tropical" in terms of their climatic range, the overall look is not particularly "tropical". The flowers, occupying the white - pink - purple range, are "pretty" rather than truly "exotic" in appearance. These trees and shrubs would fit well into a traditional landscape styled after European or North American gardens, but where it's too hot to grow classics like Rhododendron or Prunus. They would also suit a cottage-style garden or simply a purple-flowered colour scheme.
Offline references and further sources of information
Burke, D. 1984. The Story of Dr. George Hewitt and the Tibouchina. Australian Horticulture, Vol 82, March pp 6-25
Dunstan, K. 1982. Tibouchinas - The New Breed. Your Garden, April 1982 pp 10-11
Harrison, R. E. 1967. Handbook of trees and shrubs for the Southern Hemisphere 4th edition. A.H. & A.W. Reed, Wellington
Hazelwood, W.G. 1968. A Handbook of Trees, Shrubs, and Roses. 2nd Edition. Angus & Robertson Ltd, Sydney
Herbert, D.A. 1958. Gardening in Warm Climates. Angus & Robertson Ltd, Sydney
Lake. J. 1996. Glorious Tibouchinas. Australian Horticulture, August 1996 pp 14-15
Palmer, S. J. 1994. Palmer's Manual of Trees, Shrubs & Climbers. Lancewood Publishing Runaway Bay, Queensland
More information online:
Árvores do Brasil
Mostly in Portugese, but plants are identified by scientific name. Go to (Lista cientif
) so you can view photograph of T. granulosa
Synonym: Tibouchina semidecandra
Princess Flower, Tibouchina urvilleana
Urban Forest Ecosystems Institute, California
Princess Tibouchina Tibouchina urvilleana
. Online Manual of Subtropical Landscaping Plants, Palm Beach Community College, Florida
Synonym: Tibouchina grandifolia
Panthers Ear TibouchinaTibouchina heteromalla
. Online Manual of Subtropical Landscaping Plants, Palm Beach Community College, Florida
"Botany Photo of the Day", University of British Columbia Botanical Garden & Centre for Plant Research
Other species and cultivars
These have been included for informational purpose, but might not be commercially available in Australia
Tibouchina sp do Guartelá
Albarkema's "Wild flowers from south Brazil" photo album. (Guartelá Canyon is an area of geological and biological significance)
Botany, breeding, culture and other information
Meet the Breeder
Profile of Tibouchina
breeder Terry Keogh ('Groovy Baby' and others). Plants Management Australia (PDF)
Melostomataceae of the world
Extensive information on this family is presented in the following website by Darin S. Penneys (University of Florida)
Possible misspellings: Tibochina, tibachina, tiboshina, tibashina.