Thursday, November 3, 2011

Bush Butterflies

Velleia paradoxa
“Bush butterflies” is the name given to this pretty plant in Tasmania, no doubt because of the way it holds up its scented yellow flowers, so they seem to flutter above the plant.

Here, it goes by the more prosaic name of “spur velleia”.
It takes some rather close observation to find the spur after which it is named. It’s a tiny point which hangs down from the back of the flower.

I couldn’t manage to photograph it, so decided to show you the spur of a nasturtium instead. You certainly can’t miss this one! When you find a Velleia flower, check it out and you’ll find that it, too has a spur, albeit a tiny one.

To explain the spurs: You all know how seed-making works. Pollen from the male bit of a flower has to get onto the female bit of another flower. There are lots of variations on the theme of how it’s done, but a common one is for the flower to attract an insect to do the job.

It advertises with perfume and bright-coloured petals, carefully designed to direct the insect towards the centre of the flower while providing somewhere for it to stand. This aligns the insect in the desired position.

The insect is rewarded with a drink of high-kilojoule nectar, secreted by the flower from glands called “nectaries”, and in the process gets dusted with pollen, some of which brushes off on the next flower.
From a plant’s point of view, an insect which manages to get the nectar without doing the pollen transfer is a cheat and a fraud - but it happens. So flowers select their insects by providing facilities to suit those of the right size, shape, and behaviour.
One of these facilities may be a nectary spur. Insects which don’t have a long enough proboscis can’t reach down inside it to drink the nectar, so the supplies are kept safe until the right kind of insect comes along.
I’m not sure why this Velleia species was singled out to be named for its little spur, though, as a nectary spur is a common feature among the various Velleia species as well as the very similar-looking Goodenias.
Spur Velleia is potentially a good little garden plant. It is a short-lived perennial, fast-growing from seed, and producing a generous sprinkle of yellow flowers from early spring to autumn. It likes full sun, and just a bit of watering to get established. Once introduced to a suitable garden, it will self-seed each year.
This one of the Australian native plants that could easily be sold as a bedding annual, in punnets, for an instant spring garden.
Seed can be purchased from internet sources, or we can collect our own.

Telling the Goodenias from the Velleias.
There are a number of local species of Velleia and Goodenia, all with very similar-looking flowers. There are two ways to distinguish between them.
1. Velleias have a unique arrangement of the flower stem. Botanists, bless them, have a name for it - it’s called a “dichasium”. It means that the stem divides into three, with the centre stem having just a single flower, while the outer two stems each divide into three, with the centre stem having just one flower... and so on, according to the vigour of that particular flower stem. You can see it in the photo of Velleia paradoxa, above, but won’t find it on any Goodenias.
2. You’ll need to dismantle a flower to find the ovary. It’s the roundish bit that will turn into the seed capsule when it’s ripe (unless some curious person picks the flower, and dismantles it for science, first). In Velleia, the ovary is superior, in Goodenia it’s inferior. Superior doesn’t mean better! It just means that the ovary is above the point where the petals, sepals and stamens are attached. An “inferior” ovary is below that point. In some Goodenias, it is only “half-inferior”, while in others it’s clearly below the place where the petals are attached.


Tom said...

Thanks for another useful description Patricia. I found a patch of Velleia today on Mt Petrie on the edge of line of some Casaurina trees. What caught my eye was some delightful yellow flowers on a short stem. "Mangroves to Mountains" - my ref book has an id as either Velleia paradoxa or spathulata - I need to return to check more closely to see exactly which one it is. I agree - it should be a common garden plant.
Another find recently in the same reserve wss some Rubus mollucanus var triloba

Patricia Gardner said...

Hi Tom. Returning your comment on email.
To my other readers: Tom has since re-identified his Brisbane plant as Goodenia bellidifolia. I strongly recommend that you have a look at his blogsite,
He has put some lively photos of plants and wildlife on it.