Not just a flower

In the rose family you will meet not only the beautiful flowers, but also many beloved cows. So what do rose, plum and strawberry have in common? 

Written by: Zvi Atzmon, Young Galileo

What do plums, peaches, plums, cherries, apples, pears, peaches, strawberries and raspberries have in common? The first answer that comes up is: they are all juicy cows. And if we add almonds to the list, and roses too? Finding common ground will be more difficult. So here is the answer: all of these belong to the rose family. Yes, many succulents are members of the rose family, best known to us for their beautiful flowers.

The right flowers

So what do rose, plum and strawberry have in common? First of all, the structure of the flowers. Rose flowers usually have a double bract, meaning sepals on the outside and petals on the inside. Rose flowers are usually bisexual: the flower has organs that produce male gametes and also organs that have female gametes.

The male genitalia, which form the pollen grains, are called anthers, and in rose flowers there are usually a large number of them (look at the rose and try to identify them). The female reproductive organs of the plants are called leaves (singular: leaves), and they include an ovary with ovules, in which the female sex cells are located. After fertilization, the egg becomes the seed of the plant (following its germination, a new plant develops), and the entire ovary becomes a fruit.

Another thing roses have in common is that they are "true flowers". That is, the flower can be divided into two equal parts by many cutting lines (this is called "radial symmetry"). The flowers of the anemone, the primrose and the poppy (which are not among the roses) are also "true flowers"; An "incorrect" flower has only one line of symmetry, for example a snapdragon.

The poisonous seeds

The plum fruit is a pit type fruit: the outside is wrapped in a thin skin, inside is a juicy pulp that is eaten with pleasure, and inside is a hard structure - the pit, inside which is a seed. A peach has a similar fruit - except that its skin is covered with a fine down (in the variety of peaches known as nectarine the skin is smooth), while the skin of the kernel is very thick, wrinkled and grooved. In contrast, the shell of the kernel is smooth and separates easily from the surface of the fruit.

The cherry trees are also stone houses, but they are smaller. In all these fruits, the sweet or sweet-sour fruit pulp is eaten, and the seeds are bitter. The bitterness protects the seed (which should sprout and become a new tree) from all kinds of eaters. The seeds contain the bitter substance amygdalin (from the word "almond" in ancient Greek) and other substances, which break down in the digestive system and form the poison cyanide. How in almonds do you eat the seeds, which are very nutritious - rich in protein, oils and vitamins and almost free of bitterness and toxins? These are "sweet almonds". In contrast, bitter almonds contain amygdalin, their taste is repulsive and it is dangerous to eat them.

The simulated fruit

In apple flowers, the ovary - which is the lower part of the leaf (the female organ of the flower), is immersed in the substrate on which the parts of the flower sit. Such an ovary is called a "bottom ovary", and therefore the apple fruit is formed not only from the ovary (as in a "real" fruit), but from the ovary together with the substrate that surrounds it. In the language of botanists, an apple is described as a simulated fruit, while nutritionally it is of course a fruit for everything!

An apple, which is a juicy fruit with several seeds without a hard shell, is considered a berry (in this case: a mock berry). A pear is also a simulated grape formed from an ovary that sinks into the flower bed. The pulp of the pear is rich in cells that have a particularly thick wall, called "stone cells". The fruit of the hassak is also a simulated grape, the main part of which is formed from the flower substrate in which the lower ovary of the flower is immersed. Unlike apples and pears, whose seeds are quite small, the seeds of the hasak are large. The teak also differs from all the rose plants we mentioned in that it is evergreen - it does not shed its leaves in the winter; Plum, peach, cherry, apricot and almond are deciduous.

The wild strawberry and raspberry fruits are different from the fruits we mentioned: they also do not grow on trees, but on climbers (raspberries) or on low plants (grasses) and creepers (strawberries). Their flowers resemble the flowers of the plum, almond and other members of the family, but their leaves are made up of many parts, each of which creates a tiny fruit - these are the tiny bumps of the field strawberry and raspberry, and the fruit is called a clustered fruit. In field strawberries, the main juicy part is a convex juicy substrate, and therefore a strawberry is also a simulated fruit.

The flowers of the wild roses are similar to the flowers of the plum, almond, nutmeg, wild strawberry and their friends, except that their petals are larger. The leaf of a rose is made of many parts that lie in a sunken substrate, and therefore the flowers of roses (which you can see in gardens and parks) are imaginary flowers. In the varieties of cultivated roses, the flowers are "stuffed" - this means that the gardeners created varieties that do not have five petals, as is the typical number for members of the rose family, but many large petals, so that they are very impressive in appearance.

The article was published in the Galileo Young Monthly for curious children. For a gift digital sheet Click