Significant trees

Nineteenth century taste enjoyed curious plant growth forms as part of a Gardenesque style of planting championed by the Scottish gardener and writer John Claudius Loudon and first proposed in 1832. Loudon wished to differentiate gardened landscapes with exotic and dramatic form from planting that led to natural garden appearances.

Camperdown Elm was discovered about 1835 as a young sport within an Elm forest at Camperdown House, Dundee, Scotland and was transplanted into the garden where it remains, only 3 metres tall with weeping habit and contorted branches.

The cultivar has been propagated by grafting on elm rootstocks, often Ulmus glabra, and usually grows little more than 4 metres tall. It has been marketed in Victoria since 1873 and grows larger here than elsewhere with a height of 13 metres and spread of 14 metres being recorded.

Candleberry Myrtle is a component of a unique remnant flora, the Laurel cloud forest or Laurisilva of Madeira. Now only present on western Canary Islands Azores and Madeira, this forest once covered much greater areas including much of Europe, North Africa and Asia.

The Ice Ages wiped it out in most places, only where warm maritime currents and cloudy maritime mists occurred were conditions suited to its survival. Fossilised remains of a similar forest have been found in France and Czech Republic but the Madeira forest was always unique.

Plants of the Laurel family dominate the forest though there are also more familiar plants grown in Australian gardens including Lily-of-the-Valley tree (Clethra arborea) and Honey Spurge (Euphorbia mellifera).

Remarkably, though very limited in its native distribution, Candleberry Myrtle is not uncommon around the world; it is a significant weed of Hawaii, introduced by Portuguese settlers in the early 1800’s. By fixing nitrogen it changes the character of Hawaiian soils, encouraging introduced species at the cost of native species unable to tolerate fertile soils.

Large leaves up to 270mm long and 200mm wide with 270mm upright clusters of white bell-shaped flowers with orange stripes and purple spots followed by 300mm long bean-like seed pods makes Indian Bean readily recognised. Native to central south-eastern USA, it grows to 18 metres in moist woodland or stream edge environments.

Catalpa is derived from the Muscogee, the local native tribe, name for the plant, “kutuhipa” meaning winged head and has been used since mentioned by the plant collector Mark Catesby who introduced it to Britain following his visit to Charleston, South Carolina from May 1722. Catesby’s observations resulted in him being one of the first people to describe bird migration.

Catalpas enjoy a broad distribution including eastern USA, the Caribbean and east Asia.

Lindens are ancient trees found in the fossil and pollen records and used by man for centuries. Coppiced Linden was used to feed stock and archaeological evidence shows that fibre from the inside of Linden bark was used to weave clothing during Bronze Age Britain.

More recently, Linden wood has been used for its fine carving qualities both in the creation of puppets through Europe and by the master carver of the eighteenth century, Grinling Gibbons who valued not only its workability but also its light weight. His work with linden wood is in Windsor Castle, St Pauls’ Cathedral and Petworth House among others.

The Large Leaf Linden is native through much of Europe though in Britain its distribution is limited to marginal limestone areas.

Field Elm (Ulmus minor) is distributed throughout Europe spreading as far as Iran and showing slightly different characteristics throughout. It has long been recognised that trees on the north French coast in Brittany were especially upright in their growth form. It was described in Guernsey, one of the Channel Islands that form Britain’s final Norman possessions, in 1815 and introduced into broader cultivation in Britain.

Its upright growth habit made it especially popular as a street tree and it has been used widely in northern Europe for that purpose though it has proven to be susceptible to Dutch Elm Disease.

‘Sarniensis’ derives from Sarnia, the Roman name for Guernsey.

Named for the American ecologist Paul Bigelow Sears, 1891-1990, Kuni Bush is part of the fynbos flora of the South African cape. It experiences a Mediterranean climate with winter rainfall and dry summers, Kuni Bush being especially common on scree covered hillsides.

Its native habitat is noted for its biodiversity and extraordinarily high level of endemism, with approximately 8,500 native plants, 6,000 or 85% growing nowhere else. Fynbos is a fire adapted environment, and if not for recurrent fire, Fynbos would likely change to a woodland dominated environment.

Hybridisation in oaks is common with the progeny carrying characteristics of both parents. Hybrids between the English and Algerian Oaks are especially frequent in Victoria. Algerian Oak parentage is indicated by the late leaf fall or semi evergreen character of the offspring which may carry foliage through the winter and by the presence of leaf tufts on the underside of the leaf.

Trees generally grow quickly to form broad headed canopies frequently on short broad trunks.

Pittosporums are a family of about 200 mostly evergreen trees and shrubs that are native across a broad area including New Zealand and Australia, Oceania, Japan and China and parts of Africa. They are thought to be of Gondwanan origin.

Seeds of Pittosporums are sticky, their name meaning ‘pitch seed’ in Greek, and from Pittosporum illicioides the fats and oils have been used by native populations to make soap, and fibre from bark to make paper.

Pittosporum illicioides enjoys a very wide distribution through south-eastern China, Taiwan and Japan along creek alignments and moist soil above creeks and varies significantly in leaf shape from broad oval foliage to long narrow leaves. Seeds grown from a single plant will produce these variable leaf shapes though gardeners tend to select elegant narrow leafed forms for their gardens.

Chilean Pepper Tree is a component of the Matorral habitat, a Mediterranean climate shrubland that extends along the coast and coastal mountain slopes in the central portion of Chile.

Agriculture, urban development and firewood collection mean that there are limited areas of the habitat extant and low shrubs now dominate the area though at river margins and estuaries habitat remains with Chilean Pepper as a dominant component.

Chilean Pepper typically has a twisted trunk with spiny branches and is planted as a living fence in the central valley farmlands.

Once called Acacia farnesiana, this plant was named from a specimen growing in the Farnese Gardens in Rome in 1625 from seed collected in Santo Domingo in the Dominican Republic. It commemorates Odoardo Farnese (1573-1626).

This is the most widely distributed of the Acacia group of plants apparently occurring naturally from the Caribbean through Central and South America to southern states USA, much of Africa, southern Europe and south-east Asia.

Controversy rages over whether it is native to Australia where it is very invasive, especially in Queensland where it colonises channel lines and is spreading through agricultural country.