Crateva religiosa, an unusual member of the Caper family, is little known in Townsville although a few plant enthusiasts have grown it successfully here. One of our members has a fine specimen doing very well in his garden (photo below) and it is currently in flower (photo above).
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Crateva religiosa (Capparaceae) grows naturally in Cape York and the Northern Territory and also occurs across Southeast Asia and islands in the Pacific. It has long been considered a sacred tree and planted near temples, as reflected in its species name. In ideal situations it can reach 15 metres but it is much smaller in drier areas. In gardens it can be easily pruned if necessary, as the wood is very soft.

Crateva religiosa may be briefly deciduous at the height of the dry season, before putting out bright green trifoliate leaves and showy delicate flowers in terminal corymbs (photo above). The petals start out white and fade to yellow (photo below).

The fruits of Crateva religiosa (photo below) are large with a leathery surface containing numerous seeds in cream flesh. Some people notice a smell of rockmelon on opening these fruits, others find it musky or even nauseating (perhaps depending on the degree of ripening?). The fruits are relished by native mammals and considered edible but not palatable for humans.

Photo courtesy Atlas of Living Australia CC-BY 3.0, for details see:
https://bie.ala.org.au/species/https://id.biodiversity.org.au/taxon/apni/51269947#overview

Dischidia major (Apocynaceae) is a strange-looking tropical plant, native to Queensland (Cape York) and also occuring in some Asian countries. It naturally grows as an epiphyte, twining around tree trunks and branches, as in the photos above and below.

Dischidia major , sometimes called “Rattle Skulls”, has the unusual habit of bearing two distinct types of leaves at the same time. It has small, almost circular leaves growing in opposite pairs, widely spaced along its twining stems. It also has dense clusters of large, hollow, tongue-shaped leaves.

At our NPQ Townsville meeting this month, we had a close look at a potted Dischidia major grown by one of our members. We discovered each hollow leaf has an almost-hidden entrance at its base, marked by the arrow in the photo above. So what was inside? We cut open a leaf to find out – photo below.

This leaf was empty, except for roots emerging near the petiole and spreading inside the hollow leaf. However, researchers have found wild-growing Dischidia major plants typically have certain species of arboreal ants nesting in their hollow leaves. Apparently the ants benefit from a secure shelter and their waste accumulates inside the leaf together with condensed moisture.

As an epiphyte, Dischidia major does not have the opportunity to absorb nutrients from the earth. However, when it hosts resident ants, their waste creates a small private compost heap in each occupied leaf, from which the plant’s interior roots take up nutrients – a very neat symbiosis!

In cultivation Dischidia major needs very good drainage (a chunky orchid mix is suitable) and intermittent watering. Provided the plant has a sheltered spot with bright indirect light, it grows well in Townsville even though there may be no ants of the right species to occupy its leaves. The plant brought to our meeting even had flowers emerging from its twining stem (photo above, left side above the rim of the pot).

Botanical details are available at https://apps.lucidcentral.org/rainforest/text/entities/dischidia_major.htm

On our August outing to Mt Zero we chose Hakea benthamii as our P o M after finding many specimens, all flowering beautifully and spreading their lovely scent.

Hakea benthamii (Proteaceae) grows as a small-medium shrub (photo above) sometimes up to 4m high. Although its range extends from SE Queensland to near Cooktown, it is sparsely distributed on the coastal ranges and tablelands.

The perfumed flowers are creamy-white with hints of pink, growing in clusters in the leaf axils (photo above).

The fruits are hard woody capsules with an unusual beaked shaped (photo above).

Hakea benthamii was previously called Hakea plurinervia, reflecting the multiple veins in its distinctive leaves (photo above). However, its was subsequently noticed that H. plurinervia had been applied to fossil plants prior to formal description of the living plant, hence the need to change its name (Reference: Ian M. Turner (2014) “Names of Extant Angiosperm Species that are Illegitimate Homonyms of Fossils,” Annales Botanici Fennici 51(5), 305-317)

Greg brought a specimen of Cynometra iripa to our July meeting, possibly the first-ever mangrove species in our group’s long-running ‘show and tell’ tradition – thank you Greg! And the Cynometra iripa Greg has grown at home (photo below) might be the first ever cultivated in a Townsville garden?

Cynometra iripa (Fabaceae), commonly called Wrinkle-pod Mangrove, has a wide natural range along the coast of Queensland and the Northern Territory, typically growing at the landward side of mangrove forests in places with some freshwater inflow.

Cynometra iripa is usually a spreading shrub or small tree like this one (photo above) spotted by Claire and Gavin at Magnetic Island, although it has been recorded up to 8 m tall in some places.

Cynometra iripa has compound leaves with two pairs of leaflets (photo above) or sometimes a single pair. Helpful for identification, the central vein of each leaflet is slightly off-centre (photo below).

Attractive clusters of small white flowers produce woody pods (photo below) that have a wrinkly surface as the common name suggests .

At maturity these wrinkly pods are buoyant and their distribution is assisted by water currents. They are sometimes found washed up at the tideline on our local beaches (photo below).

Two other native Cynometra species have been recognised in Australia, including the new species C. roseiflora found only on the Mossman River. For more details see Cooper, W.E. (2015) A taxonomic revision of Cynometra L. (Fabaceae) in Australia, available here.

On our June outing at Cleveland Creek, we noticed clusters of tiny creamy-white flowers (photo above) on a small tree that presented an ID challenge for most of us. Thanks to John for providing the answer: Pittosporum tinifolium.

Pittosporum tinifolium (Pittosporaceae) is one of several trees commonly called Rusty Pittosporum. This attractive species was previously considered a variety of the widespread rusty-leaved pittosporum complex and named P. ferrugineum subsp. linifolium. Its separation as a species and the correction of ‘linifolium‘ to ‘tinifolium‘ is explained here: https://www.qld.gov.au/__data/assets/pdf_file/0020/69041/cayzer-chandler-austrobaileya-v10s1-p205-206.pdf

Identifying features are described by Cayzer and Chandler (see PDF linked above) as follows:

Leaves elliptic to almost orbicular, thick-coriaceous, upturned, apices rounded or acute; inflorescences multi-flowered stalked umbels exserted well past surrounding foliage. Common and endemic
to coastal areas south of Cooktown, in Cook, North Kennedy and Port Curtis districts, Queensland.

Older leaves of Pittosporum tinifolium are almost hairless/smooth (‘glabrous’ is the proper term) and the ‘rusty’ common name refers to the new growth covered in fine rusty hairs (photo above).

The woody fruits of Pittosporum tinifolium are initially green, becoming yellow to orange (photo above) before splitting open at maturity (photo below).

The genus name Pittosporum is derived from two Greek words meaning pitch (sticky) and seed. Pittosporum tinifolium fits that idea nicely with its bright red, sticky seeds displayed after the orange-coloured seed capsules split open (photo above).