Use PAGE LINKS above to view native Australian identification tree images and descriptions
Using Flowers Characteristics in Identification of Australian Tree Species
|
Introduction: Flowers are very useful in identification of native Australian shrubs and trees but are normally not the primary method (with exceptions) when identifying native species in their natural environment. Reasons for this are; the short term life span of flowers, being out of reach for closer inspection (i.e. flowers are held in the higher canopy), being rather inconspicuous and that tree species may not flower every year. An advantage of using flowers in classification is that species of the same genus will bear very similar inflorescence. Using detailed illustrations and a comprehensive language the anatomy and arrangement of flowers (the botanical term used is inflorescence) is explained on our web page below.
We hope to raise the awareness to the high conservation value of remaining old growth forests in Australia.
|
All images & descriptions are copyright © 2011 by All Creative Designs® worldwide rights reserved and not to be used without prior permission. |
| |
Flower Anatomy, Parts of a Flower
|
|
| |
|
|
1. Sepals: Extended leaf shaped structures sitting at the base of a flower. The shape of sepals can vary from leaf-like structure resembling petals to tentacle shaped extensions as shown in the Tall Nightshade Solanum nobile. Sepals are separated or fused together and with only small protrusions showing can form a crown-like shape called a calyx tube.
2. Calyx:
All sepals separated or fused together form the calyx. The calyx plays an interesting part in identificaion, as some tree species retain it to the stage of mature fruit and beyond. The Hairy Lollybush Clerodendrum tomentosum (see page 7) retains the calyx at the base of the fruit, whereas species of the genus Syzygiums (see page 10) at he top end of the fruit.
3. Pedicel: Individual flower stalk
4. Peduncle: The flowering stem individual stalks (pedicels) are attached to.
5. Petals: Petals are often brightly coloured or white parts of a flower surrounding the ovary. All petals as a unit are called a corolla. The number of petals can vary from none to numerous.
6. Stamen: The stamen is made up of the anther (the swollen sac containing male pollen) and the filament (the stem holding the anther).
7. Stigma: The stigma receives the male pollen.
8. Style: The style is a hollow tube supporting the stigma and connecting to the ovary.
9. Ovary: The ovary produces the seed. A flower carpel consists of a stigma, style and ovary.
The botanical term of the perianth refers to the calyx and the corolla as a unit especially when they are no petals present on the flower or when the calyx can't be distinguished from the corolla.
|
|
|
| |
Flowering Times and Periods
Main reasons effecting flowering times of native Australian tree species are average temperatures and to a lesser degree other environmental conditions such as sunlight and rainfall received. On the east coast of Australia average temperatures depend on altitude and proximity to the coastline. For instance the Native Gardenia Atractocarpus benthamianus will flower in July to August at low altitude in warm location, whereas at a level of 900 m flowers appear in October to November. Flowering periods can be very short only lasting for a few weeks or extend to more than 6 month as is the case with our native hibiscus species making flowers a good initial identification feature. |
|
| |
Flower Arrangements
The botanical term of inflorescence refers to the whole flowering part of a plant.
|
|
| |
Flower Spike: Flowers are attached without individual stalks (pedicels) to single a central stem.
The image to the right shows the flowering spike of the Maiden's Wattle Acacia maidenii. |
|
| |
|
Click image for full size view |
| |
Flower Raceme: Each flower is attached by its own stalk (pedicel) to a single central axis.
The flower raceme of the Grey Possumwood Quintinia verdonii is shown to the right. |
|
| |
|
|
| |
Flower Panicle: Flowers are held on a branched structure, which can be loosely shaped or
form more umbrella shaped clusters as shown in the picture of the White Elderberry Sambucus gaudichaudiana to the right. |
|
| |
|
|
| |
Flower Umbel: Flower stalks (pedicels) are attached to the same point on top of a flowering stem (peduncle).
The Lemon Myrtle Backhousia citridora shows this type of inflorescence, another good example is the inflorescence of Fire Wheel Tree Stenocarpus sinuatus (see page 5). |
|
| |
|
|
| |
Flower Corymb: A type of inflorescence where flower stalks branch off at different levels but flowers are held at a roughly even height.
Species of the Alloxylon genus Waratahs feature this flower arrangement. The Tree Waratah Alloxylon flammeum is shown to the right. |
|
| |
|
|
| |
Flowers on Australian shrubs and tree species can appear in terminal positions i.e. at the very end of young branches, in leaf axils along young growth, along older branches and on tree trunks (cauliflorous). Often tree species feature a combination of postions listed before. The picture to the right is showing a simple stalked flower appearing in the leaf axils of the Plum Myrtle Pilidiostigma glabrum. |
|
| |
|
|
|
| |
Being able to match flower characteristics with other vegetative features like leaves, bark and fruit is a safe method for correct identification of Australian tree species. See the Leaf Characteristics Page for more information. |
|
| |
| |
Links below will take you to our Australian Tree Identification images and descriptions.
|
|
|
|
All images & descriptions are copyright © 2011 by All Creative Designs® worldwide rights reserved and not to be used without prior permission.
|
|
