When I started this blog years ago, one of the main reasons was to construct an online, easily searchable and updatable repository of photos and information I gathered while researching and drawing/painting the plants I observed on Maatsuyker Island. I usually start out with little knowledge of the subject but reading and questioning often reveal hidden secrets about the magic of our natural world that bring me great joy. And so these days I approach each new blog post with an eager anticipation for the possible thrills that await. The seemingly unremarkable Exocarpos strictus did not disappoint ….
Also known as Pale-fruit Ballart or Dwarf Cherry, this plant is the only member of the Santalaceae (Sandalwood) family to have been recorded on Maatsuyker Island. During their visits in the early 1970s, Moscal and Bratt found it to be “abundant at all levels”. I saw only a couple of specimens beside the track to the Red Shed, but of course I was limited to exploring the few existing tracks.
The genus name Exocarpos comes from Greek “exo” (outside) and “carpos” meaning fruit. The image (right) shows the 2-part conspicuous fruiting pedicel, about 4 mm long. The berry-like drupe (globular, on top) changes from green to yellow to orange to red and even purplish black. The swollen fruit stalk (pedicel), seen here orange-pink, is edible and the seed (drupe) sits on top of it.
The plants on the island stand about 2m tall, with dense foliage which has that characteristic yellow-green colour of semi-parasitic plants. (Semi-parasitic plants obtain some nutrients from a host plant but also from their own photosynthesis.) Exocarpos strictus is a root parasite and host trees include Eucalyptus and, less commonly, some Acacia species. There are no Eucs in the vicinity of the plants I saw. E. nitida, the single Euc on the island, is found only near the summit. So perhaps the host tree is the sole Acacia species recorded on the island, Acacia verticillata, Prickly Moses. I did photograph some specimens close to the Native Cherry, but I don’t know if this is the host.
The leaves of the tree are reduced to scales on the angled branchlets. They can be seen in the image on the right – small, pale, triangular tooth-like structures. The yellow-green flowers are minute! only about 2mm in diameter. Sadly my only flower image is poor. The plants were already in flower when we arrived on the island in early December, and they were finished within a week. The fruit was starting to form by early January.
A fascinating comment from a Victorian in blog http://davesgarden.com/guides/pf/go/56969/ – “Now for the Kicker – I don’t plant these – I only culture them when my co-tennants plant them – As with most Santalums you need the local native furry creatures – in my case Anticinus – Kangaroo Rat – It seems the micro fauna in the saliva of the Anticinus triggers the seed – with santalums its the Dunnarts who plant them – Without this the strike rate is very poor – The creatures also know exactly where the roots for them to parasite to are and always plant them the same way – 4-5 seeds in a row planted in a groove left uncovered by the creature but quickly covered with gum leaves by the wind.”
Maatsuyker Island is home to a large number of swamp antechinus, the only native mammal to be found there. I find it intriguing to consider the symbiotic role that might allow the Native Cherry to survive on Maat.