At sheets are very important structures for plants, as it is through them that plants are able to carry out the photosynthesis, a process in which the plant is able to produce organic substances necessary for its survival.
Most sheets feature limbo petiole and sheath, and some of them may also have stipulations.
O limbo is the leaf itself, and the petiole and the sheath they are structures by which the leaf attaches itself to the stem.
Structure of a sheet
All plants have sap conducting vessels, which resemble the blood vessels present in the body of mammals, and these are the responsible for transporting sap inside the plant. They can be found in the roots, stems and also in the sheets, forming what we call leaf ribs.
In the image we can see a leaf with several leaf veins
According to the way these ribs are arranged on the sheets, we can classify them into parallellines and peninerveas. At parallel sheets have their parallel ribs among themselves, and are found in the monocotyledonous plants (which have only one cotyledon) as corn,
orchid, tulip, grasses, palm tree, sugar cane, rice, wheat, oats, barley, bamboo, rye, lily, garlic, onion, banana, bromeliad, orchid etc.
The parallel lined sheets have parallel ribs with the same thickness
already the peninerveal leaves, found in most plants, have their branched ribs and can be found in the dicotyledonous plants (which have two cotyledons) as bean, peanuts, soybeans, peas, lentils, chickpeas, pau-brasil, ipe, peroba, mahogany, cherry, avocado, acerola, rose, strawberry, pear, apple, cotton, coffee, genipap, sunflower, daisy etc.
In the image we can see that the two leaves have branched ribs
Sheets can also be classified as single sheets and composite sheets. In the single leaves the limb is not divided, While in composite leaves the blade is divided into small leaflets.
In the image we can see the difference between simple sheets and composite sheets
By Paula Louredo
Graduated in Biology
