River Red Gum - Eucalyptus camuldulensis

The River Red Gum tree (species name: Eucalyptus camuldulensis) is a common "Gum" tree along river beds across inland Australia and is also a popular plantation tree in many other parts of the world. In Southern Europe and Northern Africa the River Red Gum can be found growing spontaneously along water ways downstream from where it has been planted in plantations. The term "Red" in its common name refers to the color of its wood when milled.
Like many other Eucalyptus trees the flowers of the River Red Gum have a cone shaped cap that protects the flower while it is forming and then pops off when the flower is ready to "unfold" as can be seen in the images below.

The individual flowers are arranged in small clusters that themselves are star shaped like the one above. The picture below shows some of the detached "caps" that pop off the end of the flower buds.
After the flowers have wilted and fallen off there remains on the tree a cluster of small "fruits" that have valve like openings on the end in a star like shape. As you can see in the image below these star-like openings can have 3-6 points. The seeds inside these small fruits are released through these openings. These woody, dried fruits can be easily found at the base of the River Red Gum trees and is a good way to help identify the tree and distinguish it from other Gums.

The large tree in the image below is a tree in the "Molino de Inca" botanical garden in Torremolinos, Spain (along the Southern "Sun Coast"). It is quite common to find large specimens of the Eucalyptus camuldulensis in botanical gardens in Spain.

The leaves of the River Red Gum are long and slender with a pronounced central vein. They measure about 4-7 inches in length and about 1 inch in width.


Some other Gum trees that I have blogged about are...
Coral Gum Tree - Eucaluptus Torquata
Tasmanian Blue Gum - Eucalyptus Globulus
What makes Eucalyptus fires dangerous

Royal Poinciana - Delonix regia

The Royal Poinciana tree (Species name: Delonix regia) is native to Madagascar and is an attractive ornamental tree that is widely cultivated around the world in temperate climates. The most striking characteristic of this tree is its brightly colored flowers that range from red to orange or even yellow. Because of these bright flowers this tree is sometimes called a "flame tree" (there are several different tree species that have this distinction).

The image above shows some of the flower color variation on the same tree.
The leaves of the Royal Poinciana are very similar to those of the Blue Jacaranda (although they are not in the same family) and if the trees and young and not in bloom they can be hard to tell apart. Check this link for a discussion of how to distinguish them.

Like the Jacaranda the Royal Poinciana makes for a good shade tree partly because of the fact that it tends to grow not very tall and with a broad crown like the one in the picture above.

What makes Eucalyptus fires in Australia so dangerous?

With the recent news coming out of Southern Australia one is left asking the question "What makes the forest fires in Southern Australia so dangerous and deadly?"

Here are some answers that I have found while reading up on this...

1. Dry conditions - Australia has a lot of dry areas. Most of the Eucalyptus tree species have adapted to these dry conditions and some of them can grow in almost desert like conditions. Just this alone is a receipt for fires, trees and very dry conditions.
2. Peeling bark - Eucalyptus trees have smooth bark that peels off in long strips and falls to the ground. This gives any fire an abundance of material to burn on the ground as it spreads.
3. Flammable leaves - Eucalyptus leaves are very flammable adding to the material on the ground to keep the fire going.
4. Dependent on fires - Some species of Eucalyptus can form thickets and actually need fires to clear out the competition.
5. Flammable oils - ome Eucalyptus trees such as the "Blue Gum" produce flammable oils that make the trees either burn with incredible intensity or even explode. The Blue Gum has been called "Gasoline trees" for this reason.
   

a large Blue Gum tree

a quote from www.audubonmagazine.org...

Of the many eucalyptus species that evolved with fire, none is more incendiary than blue gum. "Gasoline trees," firefighters call them. Fire doesn't kill blue gums. Rather, they depend on fire to open their seedpods and clear out the competition. And they promote fire with their prolific combustible oil, copious litter, and long shreds of hanging bark designed to carry flames to the crowns. Blue gum eucalyptus doesn't just burn, it explodes, sending firebrands and seeds shooting hundreds of feet in all directions. Living next to one of these trees is like living next to a fireworks factory staffed by chain-smokers.

Blue Gum bark

White Sapote - Casimiroa edulis

I came across this White Sapote tree (scientific name:Casimiroa edulis or zapote Blanco in Spanish). The leaves of the tree palmate with pronounced darker gree veins on the newer leaves. The leaflets were about 4-5 inches long and had smooth margins.
I believe this tree is fairly representative of a full size tree. It stood about 5-6 meters (20-25 feet) tall. I don´t think that I would have been able to identify the tree had it not been for the sign at the base that gave its identity away. According to the sign this tree is native to Southern Mexico and central America.
The fruit of the White Sapote is a "drupe" that measure about 4-6 cm in diameter with a dark green exterior until ripe.
If this tree was at all representative of its species they do not seem to produce an abundance of fruit. There may have been about 50 fruits growing on the tree.