a brief history of how plants came to be

plants began to dominate the land millions of years ago. but before they were able to be ecologically successful and carpet the whole planet, they had to undergo numerous evolutionary requirements before becoming the mighty plants they are today.

to conquer the land, the main objective of organisms then was to protect their fragile microscopic bodies from dessication and water loss. so, the organisms developed water-proof coating on their cells or bodies(for multi-cellular organisms), which later became the cuticle we know today.

as occupants of land, the plants, being stationary organisms, had to undergo major modifications. they needed to anchor themselves to the soil. here we see how the roots developed. for anchorage, and for absorption of water and minerals which the plants needed later on.

the first problem that prevented the plants to grow into large organisms was how to efficiently conduct water and food throughout the plant body. the plants then evolved efficient fluid-conducting systems, consisting of xylem and phloem tissues. another pivotal evolution of plants was their ability to synthesize lignin on their cell walls. this helped the plants to stand erect and grow to large proportions.

the ancient vascular plants gave rise to more specialized plants with more highly differentiated plant bodies. the stems and leaves became more suited to the demands of life on land.

the leaves are the principal lateral appendages of the stem and are the primary photosynthetic organs of plants, which means they make their own food. how the leaves came about, no one really knows for sure, but there are several theories to the history of leaves. one states that microphylls("small leaf") may have evolved as superficial lateral outgrowths of the stem.

leaves start out as protuberances from the apical meristem of the shoot. leaves of plants have differing sizes and structures. this is because of specialization. they evolve according to the dictate of their surrounding environment.

the ancestral "plant" divided into two phyla. the bryophytes and sporophytes. the main distinguishing feature of bryophytes is their lack of vascular tissues, which prevents them from growing into big organisms. both became successful on their own albeit having totally different morphology.