GRASSES

-Geetha Viswanathan

The grass family has so many members. There are about 10,000 species of grass, varying in size, from the tiny to the giant ones. You’ll be amazed to know that wheat and rice are grasses too.

Grasses are found all over the world. Triticum (wheat),  Oryza (rice), Arena (oats), Saccharum (Sugarcane), Hordeum (barley) and Lea (maize) are some of them. Some grasses grow in deserts. Some in water; and some in the ice-covered polar regions.

Many years ago, about 42% of our continents were covered by grassland, giving home to large herds of grazing mammals, rodents, etc. Early hoofed mammals, like horses, lived on grazing grass, about 70 million years ago.

Most grasses are annual, i.e., they can live only for a year. They have a long, fibrous root system. They can reproduce vegetatively, by means of underground stems or runners. The leaf of the grass is long, with a leaf sheath, and veins running like parallel lines. Botanically, grass is grouped as a monocotyledon.

This is because its seed has just one cotyledon.

Grass flowers are bisexual. Both the male and female parts are present in each flower. But some grasses are unisexual too. The flowers are found in groups called spikelets. They are not brightly coloured or attractive. The flowers are pollinated by the wind.

Grass is at its best when young, when it has nutritional value. Dry grass is also useful as fodder for animals. All the cereals, which are staple food of man, are produced by grass. Three of them are rice, wheat and maize. Sugarcane, ragi, oats, millets and barley are grass products too.

Rice

Half the world’s population subsists wholly or partly on rice. This grows to a height of 50 to 100 cms. There are about 2,000 varieties of rice in the world. This plant grows best in tropical and subtropical plains, river banks and valleys. It needs a lot of water for a healthy growth. The spikelets are harvested once they become fully ripe. The seeds then come out with a coating called husk. Husk is a good source of vitamins, oil, proteins and some percentage of minerals. Nowadays, some people remove this valuable husk by polishing the rice grains.

We need the husk in the rice because of the vitamins present in it. About 90 to 94% of the rice grain is made up of starch.

Wheat

Wheat is a bigger and longer grass, compared to rice. It grows in places which experience very hot summers and very cold winters. In India, it grows in the Northern regions like Punjab, M.P., U.P., Haryana, etc. It is a staple food for North Indians.

Maize

Maize grows in tropical areas. The grain is used as food. Its dried and ground flour is used to make alcoholic drinks. The stem and dry leaves are used for roof-making and fence-making.

Sugarcane

All of us love to drink sugarcane juice. This plant is called Saccharum  officinarun, in botony.  It grows to a height of 4 to 5 mts. Within 8 to 15 months. The stems vary in diameter and colour. It is coated with a hard woody skin, and is filled with a sweet juice. Sugar is produced from this juice. The dry stem residue after the juice has been extracted, is used to manufacture wall-boards, plastics and paper.

Lawns

Agrostis and Festuca are the common grasses used to lay beautiful lawns in our homes, hotels and offices. They grow with uniform density, so that the area is fully covered.

What is Bamboo?

I am the tallest in the grass family. My stem is woody, green and hollow, jointed and glossy. My botanical name is Bambuseal. I can grow upto 30 metres in height in a month’s time.

I am used not only to make paper, but also to make furniture, boats, bridges and musical instruments. When I grow to be sixty – six years old, I burst out into flowers and die.

I do not grow as other plants do. As I grow bigger, my stem does not become thicker. So as I grow taller, there are hollow spaces between my joints.

What is Corn?

I am a grass too, but I am a little different from the others. I produce a silk in my flowers, called corn-silk. Do you know why I make this silk? My flowers are unisexual – only the male or female part is present in each flower. My male flowers do not have silk, they grow on the tip of the stem. They spread pollen grains through the air. My female flowers are present in the lower part of the stem, between leaves. These are what you eat as corn. These flowers produce fine golden-brown silk, at their terminals. This silk will capture the pollen grain when it comes in contact with it, just as a fishing net captures fish. Female flowers are well protected by a leaf like sheath. After pollination, these female flowers become seeds which you also use to make pop-corn.