#12 Correa backhouseana – the Coastal Correa

Correa backhouseana

Correa backhouseana

Two Correa species have been recorded on Maatsuyker Island – C. lawrenceana and C. backhouseana. In family Rutaceae, the genus Correa is named after the Portuguese botanist known as Abbé Correa.  Both species were first described by English botanist Sir William Hooker, father of botanist and naturalist Joseph Hooker.

The Correa is known in Australia as the native fuchsia (as are several other plants!) but C. backhouseana is the Coastal Correa while C. lawrenceana is the Mountain Correa.  James Backhouse was  an English botanist who collected the type specimen at Cape Grim in 1833. Robert Lawrence (1807-1833) was a Tasmanian botanist who, together with Ronald Gunn, collected the plant material sent to Hooker.

IMG_2256gWhen I was on the island, I had noted in my project book that “Students Flora of Tasmania” from 1975 used the spelling “backhousiana” and “lawrenciana”, while the more recent UTAS Key referred to “backhouseana” and “lawrenceana”. I discovered, through Wikepedia, that the spelling of the names was standardised under the International Code of Botanical Nomenclature in 1998.

Distinguishing the two species is not easy. From my reference sources, the main difference is in the 8 stamens. In C. lawrenceana, the stamen filaments are of uniform width while in C. backhouseana, the filaments (stalks) of the 4 stamens opposite the petals are expanded and flattened at the base. So which species was I looking at? IMG_1384gOf course I was not going to rip apart lots of flowers to study the stamens, but this photograph of a withering specimen does clearly show stamens that are broader at the base. Also “Students Flora of Tas” indicates that the stamens in C. backhouseana are scarcely exserted (sticking out beyond the corolla tube), as they are in these photos, whereas C. lawrenceana has stamens extending well beyond the fused petals.

One of the characteristics of the Rutaceae family is an abundance of oil glands, often seen as translucent dots on the leaves which produce an aromatic fragrance when crushed.  IMG_2329gThis plant is also interesting for its hairiness! The petals of the flowers are greenish-white with their outer surfaces densely stellate-hairy (hairs like stars). You can see the hairs very clearly on the outer petal surface in this image of a flower bud. But what about the stellate hairs on the new leaves?! The references all indicate that the leaves are glabrous (smooth, without hairs or scales) and shining, and certainly the older leaves are, but the photo shows lots of stellate white hairs on the young leaves.

IMG_0695gFinally, the seed pods are also hairy with the fruit separating into four 2-seeded parts. Flowering in spring and summer, I saw this shrub with buds, flowers and seed pods, sometimes all on the same plant, throughout the period of my residency. It can grow to more than 1m high, but as with many other plants on Maatsuyker Island, in the extreme conditions the plants are quite stunted. On the track under the lighthouse (SW-facing exposed slope), the shrubs were no more than 30 cm high.

20160111_213655gI bought a specimen from a Tasmanian nursery and I am growing it in my garden here in the Blue Mountains so that I will have real specimens to work with for my drawing/painting if I need them. I am working on a graphite drawing showing the stages from bud, to fully-formed flower, through to seed pod. In the meantime, here is the associated page from my island project book.

Crane fly

Crane fly

While reviewing my photos for this post, I came across this image of a bug on the Correa. I borrowed some books on Australian insects from the library but having no entomology knowledge, I didn’t succeed in identifying it.  Fortunately, I came across an excellent website called “Insects of Tasmania”. One of the owners, Tony Daley, was very helpful and promptly put a name to it – a Crane fly, possibly Ischnotoma skuseana,  although the patterning does not match exactly. Check out the website at URL – https://sites.google.com/site/insectsoftasmania/home

Looking carefully at the image, I was impressed with the mouthparts and the beautiful frilled antennae. I also saw 6 distinct legs, but what are the knobbly bits towards the back near the start of the wings? Well…. when I started to read up on Crane flies, I was confronted with a whole new world of terminology.  A Field Guide to Insects in Australia” by Paul Zborowski and Ross Storey tells me … “Possible confusion may arise between flies and the few other insects which have one pair of wings… However, flies are the only insects that have hindwing halteres.” Apparently halteres are minute dumbbell shaped organs that have been modified from hindwings and stabilise the insect during flight. Who would have thought!?!

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One Response to #12 Correa backhouseana – the Coastal Correa

  1. Pingback: My Maatsuyker Island Plant List | MaatsuykerDreaming

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