Summer Flowers

You may have noticed that one of our local wattle species is in full flower right now. Lightwood (Acacia implexa) is a long-lived small tree that is most common in our region on granite soils, including on the slopes of Tarrengower and Leanganook (Mount Alexander). The summer flowering pattern of this species stands out from our other local wattles, most of which flower between late winter and spring.

Lightwood (Acacia implexa) – photo by Frances Cincotta

Did you know that the flowers of our local wattles do not produce nectar, and are predominately pollinated by native bees that gather the pollen? With different species of wattles flowering months apart, you tend to get different species of bees that act as the primary pollinators. One of the most important groups is the Sweat Bees (Lasioglossum) which contains many different species. Birds and other insects also play a role in cross-pollination, but mostly incidentally as the pollen rubs off as they land near the flowers while foraging or perching.

Native Bee (Lasioglossum species) on wattle, taken by Patrick Kavanagh

Throughout the box-ironbark region, most of our plant species flower across winter and spring, providing nectar and pollen for countless birds, insects and mammals. There are far fewer species that flower over summer, so those that do provide a valuable food source. These include several eucalypts, such as River Red Gum (Eucalyptus camaldulensis) and Candlebark (Eucalyptus rubida), which in good years can be densely covered in nectar and pollen-rich flowers. Sweet Bursaria (Bursaria spinosa) provides food for countless insects, including the threatened Eltham Copper Butterfly. It usually begins flowering in December or January, with one study documenting flower visitation from 38 insect species, including beetles, flies, bees, wasps, moths and butterflies (Hawkeswood 1990).

Eltham Copper Butterfly feeding on the nectar of Sweet Bursaria flowers – photo by Karl Just

Several local mistletoe species reach peak flowering in summer, including Wire-leaf Mistletoe (Amyema preissii), Box Mistletoe (Amyema miquelii), Buloke Mistletoe (Amyema linophyllum) and Creeping Mistletoe (Muellerina eucalyptoides). These species produce nectar that attracts many birds, butterflies and other insects.

If you have noticed more of our local species flowering over the hot summer months, let us know in the comments!