Plants that start with O
List of plants.
Just here looking for plants? This page gives you an alphabetical breakdown of the most well-known plants, by their common names.
Oleanders are one of the most poisonous plants known. Their sap is toxic, and even the dead, dried plant is dangerous. Horses have been known to die from eating oleander leaves. Even a single leaf might be enough to kill a small child.
Olives are the fruit of a small, slow-growing tree. They are originally from the Mediterranean region and grow best in poor soils in Mediterranean climates. Olives can be grown easily from both seeds and cuttings, but trees grown from seed don't always grow good fruit.
Olives can't be eaten fresh from the tree, they are too bitter. Olives need to be prepared by soaking them in salty water or otherwise preparing them to be eaten. Some types of olive can be pressed and oil made from them.
Onions are used in almost every kind of food, raw or cooked. They can be very sharp when they are raw and many children do not like raw onions, but when they are cooked they are quite sweet.
The opium poppy has been grown for hundreds of years as a decorative garden plant, like other poppies. The seeds of the opium poppy are used in baking, sold just as 'poppy seeds'. The sap (or latex) of the poppy's immature seed head contains the active ingredient that is used to make opiates that are widely used in medicine, the most well known being the painkillers morphine and codeine. Growing poppies for opium to be harvested for recreational use is widely illegal.
An orange is the name for both a colour and a citrus fruit. Oranges are similar to lemons but are very sweet and can be eaten raw, squeezed to make juice, and can be made into marmalade. The colour orange can be made by mixing red and yellow paint.
Orchids are a very big plant family. There are more different kinds of orchid than there are different kinds of bird. Orchids are found everywhere except deserts and glaciers. Orchids are grown for their pretty flowers. You can tell an orchid mainly by one of its petals being somehow different to all the others.