Plant of the month 10/2024: Cananga odorata

Photo: Ishara Udawela

Cananga odorata (Annonaceae) occurs naturally in Queensland between Torres Strait and the Tully River. It is also native to parts of SE Asia and Near Oceania. Cananga odorata typically grows in lowland rain forest and, under good condtiions, it develops into a substantial tree (photo below).

Photo: Russell Cumming

Although Townsville is south of Cananga odorata’s natural range, specimen trees have grown well Townsville’s botanic gardens and, as we discovered recently, Cananga odorata can also succeed in a home garden. Ishara takes up the story…

“I’ve usually seen Cananga odorata as a large rainforest tree with the canopy high above and with no hopes of seeing or smelling the flowers. So, imagine my surprise while walking down a street in Forrest Beach when a branch filled with fragrant flowers brushed my face.” (photo below)

Photo: Ishara Udawela

“Later I revisited this tree together with some NPQ members. Beth with her extensive knowledge explained how the tree was a primitive (old world) tree of the Annonaceae family within the order Magnoliales – in the photo below, note the similar flower structure to magnolias.”

Photo: Russell Cumming

“We noticed some Cananga odorata fruits developing (photo below) and Beth explained that the carpels in the flowers are free and not fused, which gives rise to several fruits forming from a single flower, as opposed to the usual one fruit from one flower in less primitive species.”

Photo: Julia Hazel

Essential oil known as ylang-ylang is extracted from flowers of Cananga odorata and the species is cultivated in plantations for this purpose. Ylang-ylang is one of the most extensively used natural scents in the perfume industry.

A note for gardeners: Regular pruning might be necessary to keep Cananga odorata to a suitable size for a small garden. We noticed the main trunk of that suburban tree appeared to have been broken or cut, possibly to limit its height. This seemed to have promoted branches sprouting from the lower part of the trunk.

Plant of the month 05/2023 updated: Corymbia trachyphloia

Photo: Peter Horsfall

This tree caught Pete’s attention during our NPQ May outing but it was mistakenly identified. Later, with Russell’s expert help, it was identified as Corymbia trachyphloia (Myrtaceae).

The trunk of Corymbia trachyphloia has rough bark, tessellated, soft, grey, brown and yellow-grey (first photo below), shedding higher up to leave the upper branches smooth, pale grey to white (second photo below).

Photo: Peter Horsfall
Photo: Peter Horsfall

The leaves are narrow and lance-shaped, slightly darker green on the upper side (photo below). There were no flowers visible on the tree in May 2023.

Photo: Peter Horsfall

Seed capsules that Pete measured were 8 mm long x 5 mm wide, urn-shaped and covered with small pustules.

Photo: Peter Horsfall
Photo: Peter Horsfall
Photo: Peter Horsfall

For more information about this species (and other eucalypts) see
EUCLID https://apps.lucidcentral.org/euclid/text/intro/index.html

Plant of the month 09/2024: Astrotricha pterocarpa

Photo: Beth Ballment

During our September outing to White Mountains National Park, a tall single-stemmed shrub caught our attention. It was an intriguing ‘new’ discovery for most of us, identified by the experts in our group as Astrotricha pterocarpa.

Photo: John Elliott

We were fortunate that on this occasion we found Astrotricha pterocarpa (Araliaceae) in “full bloom” (photo above) although we needed binoculars to inspect its huge inflorescence high above our heads.

Photo: Gavin Colthart

The pale greenish-cream flowers of Astrotricha pterocarpa are covered in fine hairs. The flowers were evidently very attractive to a wide range of insects (photo above).

Photo: Russell Cumming

Astrotricha pterocarpa has large simple leaves (photo above) with a very elongated heart-shape. The leaves are arranged spirally around the upper part of the plant’s un-branching stem. The rest of the stem has conspicuous leaf scars where old leaves have been shed.

Astrotricha pterocarpa is endemic to tropical Queensland with its range extending from south of Pentland to north of Cooktown.

Photo: Julia Hazel

Plant of the month 08/2024: Harpullia hillii

Photo: Julia Hazel

On our Magnetic Island outing last month we noticed an attractive native tree in fruit (photo above) but we failed to identify it. Later the photo was scrutinised by one of our very knowledgeable members who is currently working far from home. He sent back the answer: the tree is Harpullia hillii, commonly called blunt-leaved tulipwood. Thank you Cam, for your sharp eyes and botanical expertise!

Photo: Russell Cumming

Harpullia hillii (Sapindaceae) is endemic to eastern Australia, occuring naturally in dry rainforest, gallery forest and littoral rainforest in Queensland and New South Wales. There are only a few records near Townsville, including Russell Cumming’s observation near Cape Cleveland (photo above) and ours at Magnetic Island. It seems we are close to the northern limit of this species’ natural range.

Photo: John Elliott

Harpullia hillii bears panicles of small whitish flowers (photo above) that develop into showy clusters of orange fruit (photo below).

Photo: Russell Cumming

When ripe, each lobe of the fruit contains a single large seed wrapped in a red aril (photo below).

Photo: Russell Cumming

Propagation from fresh seed is reported to be straight forward. With its dense leafy crown and attractive fruits, Harpullia hillii could be a desirable shade tree in a park or large garden.

Plant of the month 07/2024: Lithomyrtus obtusa

Photo: Julia Hazel

Lithomyrtus obtusa, also known as Beach Myrtella, is a very attractive small shrub, native to Queensland. It draws extra attention during the winter months when it is covered in flowers ranging from pale pink to bright magenta (photo below).

Photo: Russell Cumming

Lithomyrtus obtusa (Myrtaceae) occurs naturally along undeveloped parts of the Queensland coast, typically in heathland, open woodland and sandy dunes behind the beaches (photo below). Its range extends from the tip of Cape York to about Bundaberg.

Photo: Roger Fryer and Jill Newland

The leaves of Lithomyrtus obtusa have distinctive recurved margins and pale undersides due to a coating of fine matted hairs (photo below).

Photo: Russell Cumming

Lithomyrtus obtusa fruits change from green to brown as they mature (photo below). They were eaten by some Indigenous communities.

Photo: Russell Cumming

Lithomyrtus obtusa could be a delightful garden subject but it is rarely seen in cultivation, probably due to difficulty in propagating it. If you’ve had success with seeds or cuttings of this species, please let us know!

Plant of the month 06/2024: Pandorea linearis

Photo: Julia Hazel

Pandorea linearis (Bignoniaceae) is an uncommon Queensland endemic, known to occur naturally only between Paluma Range and Stannary Hills near Herberton.

Finding Pandorea linearis flowering and fruiting in the Mt Zero area was a highlight of our recent outing.

Photo: Julia Hazel

Vigorous twining stems of Pandorea linearis had spiraled their way up burnt tree trunks (photo above) and held clusters of creamy flowers high up above our heads (photo below).

Photo: Julia Hazel
Photo: Julia Hazel

Concurrently with flowers on some Pandorea linearis vines, other vines had already developed sturdy pods (photo above) and one had ripe seeds (photo below).

Photo: Malcolm Tattersall

Pandorea linearis can of course be grown from fresh seed and it has also been successfully propagated from cuttings by some of our members.