Trans-Tasman violet allies flowering in unison

It probably has no significance at all, but back in late August I noticed that the local Tree Violet (Melicytis angustifolius subspecies divaricatus; previously Hymenanthera dentata) was flowering at the same time as the garden Sweet Violet (Viola odorata). They are both in the same family, Violaceae, which is why I noticed.

There are about 15 species of Melicytus (including those previously in Hymenanthera), from Australia (and the off-shore island Norfolk, and island and territory, Lord Howe), New Zealand (various islands) and through into the Pacific.

Then the third occurrence that proved the flowering rule, whatever that might be, was a large multi-stemmed tree in Melbourne Gardens labelled Chatham Island Mahoe (Melicytus chathamicus), in full bloom at exactly the same time.

You might say it has something to do with pollinators, and when the right insect is about. That could be true for both Melicytus which have very similar looking flowers. For the ground violet, though, I'm assuming something else favours their wayward blooms.

Here I want to illustrate and talk about the Mahoe, or at least one of the things called a Mahoe in the Pacific region. The name is applied to a few Hibscus species as well as a Hymenanthera from Norfolk Island, Hymenanthera latifolia. Our Chatham Island Mahoe was once treated as a subspecies of the Norfolk Island Mahoe.

The botanical name for the Chatham Island Mahoe means something like the honey pot from Chatham Islands (meli for honey, kytos for pot or hollow container, and chamamicus from the Chathams). So these flowers do provide a reward for whatever insects are about in late August. 

In the case of this lovely old specimen in Melbourne Gardens, the flowers are all female, each flower with a honey-like perfume. Various flies, bees and other insects visit the New Zealand main-island species of Melicytus, seeking out the prominent and bountiful nectaries in both male and female flowers.

Compared to pictures and descriptions of this species on the web, e.g., the leaves on our bush are less toothed - sometimes entirely entire. The petals are pale yellow in colour which, while matching descriptions is not always the case in photos, and it makes them look a little more like other New Zealand and Australian species..

The Chatham Island Mahoe grows mostly in coastal forest, but occasionally in coastal scrub or on limestone outcrops. It seems very much at home in a protected garden bed on the high side of Melbourne Gardens.