3 Feb 2022

Sydney Goes Troppo - tropical plants flourish this month

February's hot humid weather is perfect for this month's selection of tropical plant stars.

Enset, Abyssinian Banana - Ensete ventricosum

This enormous relative of the cultivated banana is beginning to flower this month. This also means the plant will slowly die over the coming months, as it only flowers once before dying (monocarpic). The fruit may look like a super-sized banana but it is insipid and full of hard black seeds. The plant is an important source of food in Ethiopia where it originates but it is the fleshy roots, underground corm and pseudostem that are eaten.

Ivory Curl Flower - Buckinghamia celsissima

This small genus of two species was named after the Third Duke of Buckingham and Chandos, Richard Grenville, who was Secretary of State for the Colonies in 1866 to 1868. Endemic to north eastern Queensland this tree can grow to 30 metres in its native habitat but is much smaller in cultivation. The white to cream flowers occur in large racemes that droop down from the end of the branches and have a wonderfully strong fragrance that is attractive to both pollinators and visitors. It is commonly used as a street tree in Brisbane.

Blue Ginger - Dichorisandra thyrsiflora

The common name suggests this plant is a ginger but it is a member of the spiderwort family. An erect herbaceous perennial from south eastern Brazil it grows from rhizomatous root stock and likes shady locations. Dark glossy leaves are spirally arranged along the fleshy cane-like stems but it is the deep purple flowers that appear in summer that steal the show. The flowers are pollinated by buzz pollinators such as the Australian Blue Banded Bee (Amegilla cingulata) that release pollen by vibration.

Chandelier Tree - Medinilla cummingii

One of 190 species in the genus, this species comes from moist, high altitude forests in the Philippines. It has pink flowers clustered on pendant stalks giving the plants its common name. The base of each cluster of flowers has a large pink bract that covers the flowers like a hood. Flowers are followed by small, round black fruit. The large leaves have prominent veins and new growth is burgundy red. The central midrib helps channel water from the leaves, important in areas of very high rainfall where the plants occurs naturally.

Mt Spurgeon Black Pine - Pectinopitys ladei

This rare species is endemic to Mt Spurgeon and Mt Lewis on the Atherton Tableland in northern Queensland. It grows in rainforests at elevations of 1000 – 1200m and can reach 20m tall in its native habitat. Plants are either male or female and pollen from the male cone is transported by wind to the ovules of the female cone. The single seeds found on female trees are surrounded by red or purple flesh, like a plum and are eaten by birds that distribute the seeds.

Pink Doughwood or Pink Euodia - Melicope elleryana

This fast-growing rainforest tree from NSW, Queensland and New Guinea can grow to 25 metres tall. In late summer trees are covered in clusters of small pink flowers along their branches. The flowers attract a range of nectar feeding birds including our noisy Rainbow Lorikeets. In tropical North Queensland, leaves of the tree are the favoured food for the larvae of the Ulysses Butterfly, Papilio ulysses.

Scarlet Rosemallow - Hibiscus coccineus

Also known as the Swamp Hibiscus this is a native of wetlands and marshes in south-eastern United States. It is a herbaceous perennial, meaning it is dormant over winter, when the stems are often cut close to ground level. It is a vigorous grower and in summer produces large showy scarlet red flowers with a prominent central staminal column. As well as the showy flowers, the shiny green palmately compound leaves look like hemp leaves. It grows best in rich wet soil and can even be grown in a shallow pond.

Red Beech - Dillenia alata

Found in the coastal rainforests of the Northern Territory and Queensland, this small tree grows to 6-10 metres. The genus is named for John James Dillenius, a German botanist who became a botanical professor at Oxford. Bright yellow flowers with papery petals and red fleshy stamens are stunning but only last one day. Fruit begins green but turns bright red as it opens to reveal black seeds. As trees mature, they develop attractive pink-red flaking bark on the trunk, hence the common name Red Beech.