Kingdom Plantae-Overview 

     Plants are incredibly diverse and are composed of roughly 280,000 different oraganisms.  Around 1.2 billion year ago, cyanobacteria (blue green algae) covered the earth.  This bacteria most likely was ancestral to the same plants that colonized land rougly 500 million years ago. Each plant is subdivided into different groups based off similar characteristics and evolutionary adaptations.  Land plants closest reletives are green algae-specifically charophyceans.  Modern land plant and algae share 4 key traits: 

• Rosette cellulose synthesizing complexes 
• Perioxsome enzymes 
• Flagellated sperm 
• Formation of a phragmoplasts

Beyond obvious traits, land plants have been closely linked to charophyceans through genetic evidence.   

A sample phylogeny of land plants may look like this ^[1]

Bryophyte-Seedless Vascular plants-Gymnosperms--Angiosperms 

^[2][3]