All living things depend on other organisms for their survival. This month’s must-see plants at the Royal Botanic Garden Sydney have relationships with animals, insects and fungi. Find out more in the videos below.
Song of India - Dracaena reflexa var. linearifolia
Commonly known as the Song of India, there are many cultivars and forms of this species popular in gardens and as indoor plants. This rarely seen variety originates in Madagascar and the Mascarene Islands.
In late summer it is covered in small white flowers rich in nectar that attract bees to the Yellow Wood Garden near the Succulent Garden. Plants grow 3 – 5 metres tall and are easily propagated by cuttings. Fruit of the species are important to the diet of the Malagasy Black and White Ruffed Lemur, unfortunately neither animal can be found in this garden.
Chandelier Tree - Medinilla cummingii
This is one of 190 species in the genus Medinilla and 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 occur naturally.
Spineless Yucca - Yucca gigantea
Yucca gigantea is the tallest of all Yucca species growing to ten metres with a large swollen trunk. It is native to Mexico and Central America and like other species of Yucca has fragrant flowers that open at night.
Flowers are pollinated by moths who lay their eggs in the ovules of the flower before transferring pollen to the flower’s stigma. The moth’s larvae hatch and feed on a small proportion of the developing seeds, so that both moth and plant benefit in a mutualistic relationship.
Swiss Cheese Plant - Monstera adansonii
This climbing plant from the Aroid family (Araceae) is widespread in the West Indies, Central and South America. Fenestrate holes in the leaves give the plant its common name and endear it to indoor plant lovers.
Visit the historic Palm Grove at the Garden to see plants climbing palm trunks and exhibiting both flowers and fruit. Flowers are indicative of the family, with a white hooded spathe that surrounds a collection of flowers arranged on a columnar spadix.
Holm Oak - Quercus ilex
These broad domed evergreen trees from Mediterranean Europe and Turkey are common in the Garden, many planted in the late nineteenth century. Look closely at the end of branches and you will see acorns forming.
The Holm Oak is a host species for Black Truffles. Truffles grow in an ectomycorrhizal association with the tree's roots, helping the tree access nutrients and the fungus access sugars. Holm Oaks are often inoculated with the fungus to cultivate truffles commercially.
Pink Doughwood or Pink Euodia - Melicope elleryana
This fast-growing rainforest tree from New South Whales, 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 the famously noisy Rainbow Lorikeet. In tropical North Queensland, leaves of the tree are the favoured food for the larvae of the Ulysses Butterfly, Papilio ulysses.
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 and 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.
Ironstone Range - Breynia cernua
Burgundy foliage and a weeping habit make this a stunning feature plant in our Australian Rainforest Garden. Small brown flowers appear in the leaf axils and are followed by small, round, fleshy red fruit.
Like other members of the genus they are thought to be dependent on Leaf Flower Moths (Epicephala spp.) for pollination. As with the genus Yucca these moths lay eggs near the ovules of the flowers and the larvae feed on developing seeds. The species occurs naturally in the Northern Territory.
Join a Guided Walk of the Garden with one of our knowledgeable Volunteer Guides on Friday, Saturday, Sunday or Monday. Find out more here (availability may be temporary unavailable at times due to COVID-19 restrictions).