Monday, April 27, 2009

Atlas Cedar - Cedrus Atlantica

The Atlas Cedar tree (Cedrus atlantica) is a very close relative of the Cedar of Lebanon (Cedrus libani). Its native range is in Northern Morocco and especially the Atlas mountains from which it derives its common name. It is also found in Southern Spain as well.

Atlas cedar is a primary source of timber in Morocco. Another use for this tree is as a source of essential oil that it rich in rich in himachalenes (70%). It is also used in the production of perfumes. The Cedarwood essential oil is extracted by steam distilation and can be produced from the sawdust, chips and cutoffs that is left over after the logs are milled.

Although it is difficult to tell an Atlas cedar from a Lebanese Cedar they are both easily distiguished from other evergreen tree species and especially from other trees that go by the name cedar. Atlas cedars can be identified by their "rosettes" (clusters of needles on a short stem). These rosettes have 30-40 needles each that are about 3/4 of an inch long. In contast Himalayan cedars have fewer needles on the rosettes and longer needles.

Some trees that go by the name "Cedar" but are not members of the Cedrus genus are...

Saturday, April 18, 2009

Cook Pine - Araucaria columnaris

The Cook pine (species: Araucaria columnaris) is a tree native to the Cook Islands (north-east of Australia in the South Pacific). It is often confused with its close cousin the Norfolk Island Pine (Araucaria heterophylla). If you have come across either of these tree species I hope that this post will help you to distinguish between the two. The first distinctive of the Cook pine is its tendency to has a slight "S" curve in its trunk. It almost never grows perfectly straight despite the name "columnaris". In very tall specimens in is pretty straight but even then you should be able to see some curvature close to the base of the tree. The Norfolk Pine on the other hand has a very straight trunk.

The second distinctive of the Cook pine is its flaky bark. Unlike the Norfolk pine the bark of the Cook peels off in thin paper like sheets like in the image above. If the curvature in the trunk does not solve the puzzle the flaky bark is a dead giveaway. I´m not sure if on the older more mature specimens this flakiness is less pronounced or not.

The third distinctive is the large flower like pollen cones that grow on the ends of the leaf-branchlets near the top of the tree in late spring. It is a lot less common to see this trait and on some trees these "flowers" are less pronounced than those in the image above.

The leaves of the Cook pine are for all practical purposes identical to those of the Norfolk pine. The branches though do give a clue. One the Cook pine the "layers" of branches tend to grow closer together making the younger specimens look more filled out with a christmas tree sort of look. The Norfolks on the other hand tend to have much more space between the layers of branches. Also the branches of the Cook tend to droop down more than those of the Norfolk. In addition the branches of the Cook tend to break off closer to the main trunk and then grow secondary branches giving the taller Cooks are thinner more column like apprearance.
This tree is also sold as a houseplant although it is often confused with the Norfolk and labeled as a Norfolk. The two species are very diffecult to tell apart when they are as small as the tree in the image below. On both the Cook and the Norfolk the juvinile leaves have a markedly different look than the leaves on more mature trees.

If you do have one of these as a houseplant keep in mind that it has a very low tolerance for freezing temps.

Thursday, April 16, 2009

Norfolk Pine - Araucaria heterophylla

The Norfolk Pine ( Araucaria heterophylla) is originally native to Norfolk Island (East of Australia in the South Pacific). For more than a hundred years now it has found its way around the temperate zones of the world as an ornamental tree and even as an indoor potted tree. It is however often confused with the Cook Island Pine and a lot of people are not even aware that there are two seperate tree species.

In Spanish this tree species is called the "Pino de Pisos" (Pino means pine and "pisos" is a word for the floors of a multistory building). This name refers to the fact that the branches of the Norfolk pine branch out in a sort of layered fashion with all the ranches of any given layer branching out at exactly the same height. When seen from above the branches form a star shape pattern which is part of its ornamental appreal.

The leaves of the Norfolk pine, like all of the araucarias, are very unique and different. In the image above each branchlet is a long compound leaf with the little barb like protrusions are the leaflets that cover the length of the leave in a spiral pattern. At the end of the branches life cycle the whole leaf-branchlet dries and falls of the tree. These make interestng ornaments as well.

The bark is one of the keys to distinguishing the Norfolk from the Cook pine. The Norfolk is not flaky like the Cook pine but has a sort of rough, bumpy, course sandpaper sort of look.

The image below is the flag of Norfolk Island with the Norfolk pine in the middle.