This is the life cycle of a Purple Coneflower (Echinacea purpurea) as I have witnessed it by playing with them for two years.
Plant the coneflower seeds 
I plant coneflower seeds in a pot and label them
so that I know whether or not they germinate
When the leaves are at the size shown above, they come out of the pot and go in the ground. The leaves will grow to four times this size before a flower stalk emerges.
bud 
bud with petals emerging 
petal color emerging 
coneflower in full bloom 
coneflower with circle of yellow pollen 
pink petal color and orange cone has faded
lifecycle is nearly complete
The final stage is waiting for the cones to dry out and turn brown then collecting the cones for seed harvesting [see my post, GARDEN TIP: Echinacea (Coneflowers) which has a bad link for some weird reason].