Category: Biology (Page 1 of 2)

Clove tree plantations are now widely grown in several parts of the wet tropics.

Spice islands tree key to seventeenth-century colonisers’ trade

June 16, 2023 / John Halkett

Clove plantations were forbidden by the seventeen century Dutch outside a few islands in the Moluccas to preserve their monopoly.

Along with other ‘spices’ cloves (Syzygium aromaticum) were part of the driving force behind the rush by the European seventeenth-century colonising nations, including the Dutch, British and Spaniards to find a passage around Cape Horn to ‘claim’ parts of southeast Asia and exploit the ‘spices’ and ship them back to Europe where they were valuable and a welcome improvement to traditional diets.

Cloves are one of the prized spices traded since ancient times through… Read more “Spice islands tree key to seventeenth-century colonisers’ trade”

Grass trees are extremely slow growing and often very long-lived. — Grass trees are extremely slow growing and often very long-lived – some are estimated to be 350 to 450 years old.

Iconic grass trees a distinctive feature of inland Australia

May 31, 2023 / John Halkett

Perennial, flowering plants with some species growing to six metres tall.

Grass trees (Xanthorrhoea) are an endemic Australian genus of 28 species, only a few of which grow substantial above-ground stems. They are iconic perennial, flowering plants with the smallest species growing to about a metre and others reaching 6 metres tall.

Grass trees have a unique structure, with a true stem of fibrous conducting tissue supported by a sheath of tightly packed old leaf bases glued by a reddish crystalline resin.
Hundreds of very narrow, hard-textured leaves radiate from the apex of each branch. … Read more “Iconic grass trees a distinctive feature of inland Australia”

Stretches of coastline, such as in the North Island Bay of Islands, are famed for the massed flowering of crimson pōhutukawa.

Coastal beauty a New Zealand Christmas celebration

November 7, 2022 / John Halkett

The pōhutukawa is one of twelve Metrosideros species endemic to New Zealand and has an important place in New Zealand culture for its strength and beauty.

The pōhutukawa (Metrosideros excelsa), is New Zealand’s most colourful flowering tree. Its canopy bursts into a sheet of brilliant crimson red (or occasionally orange, yellow or white) blossom in early summer, which earns it the alternative name of New Zealand Christmas Tree.

Pōhutukawa is a coastal evergreen tree in the myrtle family, Myrtaceae and it found on the Northern half of the New Zealand ‘s North Island, evergreen coastal forest… Read more “Coastal beauty a New Zealand Christmas celebration”

Federal Oak, Parliament House grounds, Melbourne. Planted to symbolise Empire solidarity and the value of Australia’s British origins.

Algerian oak planted to mark British superiority

September 2, 2022 / John Halkett

Tree planting to mark first all-Australian conference in February 1890 to discuss the introduction of a federal system of government.

Australia’s foundation strong colonial ties continued to be evident in the selection of trees planted to mark formal occasions, such as visits by British royalty or a commemoration by early Sydney-based governors and other dignitaries.

When the NSW Premier Sir Henry Parkes presided over the first all-Australian conference in February 1890 to discuss the introduction of a federal system of government, he planted and an oak tree in the gardens of Parliament… Read more “Algerian oak planted to mark British superiority”

Isaac Newton’s Woolsthorpe Manor, Lincolnshire apple tree certified as one of 50 Great British Trees.

Foundation tree of scientific knowledge

July 8, 2022 / John Halkett

An apple tree has grown at Isaac Newton’s mother’s Lincolnshire home for hundreds of years, honoured as the inspiration for his celebrated science.

In 1666 Isaac Newton asked: “Why should that apple always descend perpendicular to the ground? … Why should it not go sideways, or upwards, but constantly to the earth’s centre? Assuredly, the reason is, that the earth draws it.” With that the origin story of Newton’s theory of gravity was born.

Seventeenth century philosopher William Stukeley records the after dinner with this friend Isaac Newton, the two of them went outside where, “under the … Read more “Foundation tree of scientific knowledge”

Dragon’s Blood trees … their bizarre shape, like umbrellas blowing inside-out, helps them to survive on the arid, thin soil.

The spectacular and bizarre Dragon’s Blood tree – get one for your garden

November 4, 2021 / John Halkett

Eerie demeanour heightened by the tear drops of translucent blood-red resin that ooze from wounded limbs.

Very trendy across Sydney, and as dear as poison the Dragon’s Blood tree is a cross somewhere between spectacular and bizarre.

Endemic to the Yemeni island off Socotra, near the Horn of Africa Dragon’s Blood (Dracaena cinnabari) trees have an eerie, prehistoric aspect. Their bizarre shape, like umbrellas blowing inside-out, helps them to survive on the arid, thin soil that covers the island’s granite mountains and limestone plateaus. Rainfall is rare, but occasional… Read more “The spectacular and bizarre Dragon’s Blood tree – get one for your garden”

Impressive kapok trees – the tallest tree on the African continent, soaring up to as high as a 20-story building, with a huge dense spreading canopy. Kapok tree cluster - isolated on white background

From mattresses to psychotherapy – the amazing kapok tree

September 15, 2021 / John Halkett

The tallest tree on the African continent

I remember back in the last century when I was a kid sleeping on a kapok mattress. Put your hand up if you remember doing the same.

Of course, kapok filled mattresses are a product of the kapok tree (Ceiba pentandra). A tree that when mature is an impressive sight – the tallest tree on the African continent – soaring up to as high as a 20-story building, with a huge dense spreading canopy. Not surprisingly local inhabitants usually referred to kapok trees as “pillars that support the sky”.

When young the kapok tree trunk is bright green with groups… Read more “From mattresses to psychotherapy – the amazing kapok tree”

The Avenue of the Baobabs a famous attraction with perhaps more than 100 trees in the whole grove.

Madagascar baobabs – a worldwide attraction

July 7, 2021 / John Halkett

The remnants of what was once a more extensive forest.

There are few avenues were people drive out just to see at sunset, but the Avenue of the Baobabs at Morondava draws admirers from all over the world. A dusty road half an hour’s drive north of the town of Morondava on the west coast of Madagascar passes through a stunning grove of baobabs, the remnants of what was once a more extensive forest.

The famous Avenue of the Baobabs has perhaps more than 100 trees in the grove. The species – the biggest and most famous of Madagascar’s six species of baobabs – is Adansonia grandidieri taking its name from two… Read more “Madagascar baobabs – a worldwide attraction”

Consulting engineer Brett Halkett gets up close and personal with the Akatarawa giant rātā in thick forest near Wellington.

Akatarawa giant rātā – a secret New Zealand tree treasure

October 15, 2020 / John Halkett

The now New Zealand piece of the once great southern continent Gondwanaland drafted south before the Australian eucalypts evolved, but did, and still does, host a eucalypt ancestor, the Metrosideros trees, including the pohutukawa, or New Zealand Christmas Tree, plus the Northern and Southern rātā trees. So, no eucalypts (or snakes) made it onto the New Zealand as Gondwanaland fragmented – all those millions of years ago.

Talking about rātā trees, hidden in the Akatarawa Forest, near New Zealand’s capital city of Wellington, is one of the country’s best kept tree secrets – reported as a living… Read more “Akatarawa giant rātā – a secret New Zealand tree treasure”

Image of BC coastal temperate forest — BC coastal temperate forest … a mild, wet climate supports species such as western red cedar, Douglas-fir, western hemlock, amabilis fir and Sitka spruce.

British Columbia… awe-inspiring trees and forests

February 4, 2020 / John Halkett

Back from Canada where again I was super impressed with the extent and spectacle that British Columbia’s (BC) towering trees and forests present. These forests are truly massive, covering an area of about 60 million hectares. You could drop both France and Germany into BC’s forests and they would disappear beneath the trees. Not forgetting of course that they provide habitat for an iconic population of North American large animals such as black bears, cougars, deer, coyotes and grey wolves.

Most of the remainder of BC consists of alpine or other naturally unforested areas like wetlands and … Read more “British Columbia… awe-inspiring trees and forests”