Vriesias (Latin names: "Vriesia" and "Guzmania") are like urn plants, but they have no spines and their leaves are softer. They are often sold in flower shops (and sometimes in supermarkets) and are very easy to look after. Their flowers grow on a single stem, protected by flattened, colourful leaves. It is better not to fill the central space with water, as these soft-leaved plants might rot. instead their soil should be watered.
Spanish moss (Latin name: "Tillandsia usneoides") is a grey plant found hanging from trees in the swamps of the southern United States, especially in Louisiana but as far east as coastal Virginia. To the south it spreads as far as Chile and Argentina. It gained its current name from Spanish and French colonisers in the Gulf of Mexico. The French called it "Barbe Espagnole" ("Spanish beard") to insult their rivals, and the Spanish in turn called it "Cabello francés" ("French hair"). Today "Spanish moss" survives as a mild version of the French taunt, although some call the plant "Graybeard".
Bromelia, the plant which gives its name to the family, is the only other bromeliad with edible fruit. Its berries taste a bit like pineapple, but are less tasty, and there are not very many on each plant.
Fascicularia is the only bromeliad that can be grown in frosty areas. It is not killed by frost if it is kept dry in the winter.
Pitcairnia is the only wild bromeliad outside the Americas. One species, "Pitcairnia feliciana", was discoved living in West Africa. It is probably descended from seeds carried by migrating birds.
Puya is the largest bromeliad. It can grow up to nine metres tall. It lives in the Andes mountains, and is sometimes eaten by bears for its nectar. In Chile the young leaves of some puyas are eaten in salads.
Eucalyptus
Eucalyptus is a genus of trees. There are over 700 species of eucalypts, and almost all of them are in Australia. Eucalypts can be found in almost every part of the Australia, and they are adapted to many different habitats.
"Eucalyptus" is one of three similar genera that are commonly referred to as "eucalypts", the others being "Corymbia" and "Angophora".
Many species, but far from all, are known as gum trees because they exude copious sap from any break in the bark.
Eucalypts have many local names, like 'gum trees', 'mallee', 'box', 'ironbark', 'stringybark' and 'ash'.
Eucalypts have special flowers and fruits that no other trees have. When it flowers a bud cap made of petals grows around the flower until it is ready to open. Then the bud cap falls off to reveal a flower with no petals.
The woody fruits are called gumnuts. They are roughly cone-shaped and open at one end to release the seeds.
Nearly all eucalypts are evergreen but some tropical species lose their leaves at the end of the dry season. The leaves are covered with oil glands. These oils are often used to treat coughs and colds.
Many eucalypts also change the shape of their leaves as they get older. Young eucalypts have round leaves. When one to a few years old, the leaves of most kinds become longer and spearhead or sickle shaped. A few kinds keep the round leaf shape all their lives. Most species do not flower until the adult leaves starts to appear.
The bark dies every year. In smooth-barked trees most of the bark falls off the tree, leaving a smooth surface that is often colourfully marked. With rough-barked trees the dead bark stays on the tree and dries out. Many kinds of eucalyptus trees have smooth bark at the top but rough bark lower down. These different kinds of bark are used to arrange the eucalypts into groups – this is useful because there are hundreds of kinds of eucalypts, and breaking down the group in this way makes the group easier to understand.
The different groups are:
Today, specimens of the Australian Mountain Ash, are among the tallest trees in the world at up to 92 metres in height and the tallest of all flowering plants: taller trees such as the coast redwood are all conifers. There is evidence that at the time of European settlement of Australia some Mountain Ash were indeed the tallest plants in the world.
Most eucalypts cannot survive frost, or can only stand light frosts down to -3 °C to -5 °C. The hardiest eucalypts are the so-called Snow gums such as "Eucalyptus pauciflora" which is capable of withstanding cold and frost down to about -20 °C. Two sub-species (wild varieties) of this tree can survive even colder winters.
Several other kinds, especially from the high plateau and mountains of central Tasmania, have produced extreme cold-hardy forms. It is seed from these hardy strains that are planted for ornamental trees in colder parts of the world.
An oil found in eucalyptus leaves is a strong, natural disinfectant, which is used in some medicines, but can be poisonous if too much is taken. Several marsupials, such as koalas and some possums, are partly resistant to it. These animals can tell which plants are safe to eat by their smell.
Eucalypts make a lot of nectar, providing food for many insects.
Eucalypts have a habit of dropping entire branches off as they grow. Eucalyptus forests are littered with dead branches. The Australian Ghost Gum "Eucalyptus papuana" is sometimes called the "widow maker", due to the high number of tree-felling workers who were killed by falling branches. Many deaths were actually caused by simply camping under them, as the trees shed whole and very large branches to save water during droughts. For this reason, you should "never" camp under large eucalyptus branches.
On warm days eucalyptus oil vapour rises above the bush to create the well-known distant blue haze of the Australian landscape. Eucalyptus oil catches fire very easily, and bush fires can travel quickly through the oil-rich air of the tree crowns. The dead bark and fallen branches are also flammable. Eucalypts are well adapted for periodic fires – in fact most species are dependent on them for spread and regeneration. They do this in several ways: by sprouting from underground tubers, hidden buds under their bark and from seeds sprouting in the ashes after the fire has opened them.
Eucalypts began between 35 and 50 million years ago, not long after Australia and New Guinea separated from Gondwana. Their coming coincides with an increase in fossil charcoal deposits (which might mean that fire was important to them even then), but they remained a minor component of the rainforest until about 20 million years ago, when the gradual drying of the continent and lessening of soil richness led to the growth of a more open forest type, with mainly "Casuarina" and "Acacia" trees. With the arrival of the first humans about 50 thousand years ago, fires became much more frequent and the fire-loving eucalypts soon came to account for roughly 70% of Australian forest.
Eucalypts grow back quickly after fire.
The two valuable timber trees, Alpine Ash and Mountain Ash, are killed by fire and only grow back from seeds. The same fire which had little impact on forests around Canberra has resulted in thousands of hectares of dead forests.
Eucalyptus have many uses which have made them important. Because of their fast growth, the main benefit of these trees is the wood. They provide many uses, such as planting in parks and gardens, timber, firewood and pulpwood. Fast growth also makes eucalypts suitable as windbreaks.
Eucalypts draw a very large amount of water from the soil. They have been planted (or re-planted) in some places to lower the water table and reduce the amount of salt in the soil. Eucalypts have also been used as a way of reducing malaria by draining the soil in such places as Algeria, Sicily mainland Europe and California. Drainage removes swamps which provide a habitat for mosquito larvae, but such drainage can also destroy harmless habitats by accident.