When you want to learn to draw flowers step by step you landed on right place.
Carol Rosinski is a professional illustrator and artist and art teacher who wrote a wonderful book with title and sub-title which convey very well what kind of rare teacher she is:
"Don't be misled by this book's small size! Carol Rosinski is a knowledgeable, gentle authority who will take you by the hand and talk to you while you "get started" learning to draw...
Rosinski goes beyond simple demonstration to explain the reasons and feelings that make each element essential to a good drawing. She never wants you to accept what she says as true just because she says it: she wants you to experience for yourself the point she is discussing.
With such an able guide at hand, you'll have no trouble "getting started" on a drawing project! This book is a "must have."
..and check also the how to make a rose tutorial from the same artist!
Here some quotes on flowers!
Flowers... are a proud assertion that a ray of beauty outvalues all the utilities of the world. ~Ralph Waldo Emerson, 1844
Flowers have an expression of countenance as much as men or animals. Some seem to smile; some have a sad expression; some are pensive and diffident; others again are plain, honest and upright, like the broad-faced sunflower and the hollyhock. ~Henry Ward Beecher, Star Papers: A Discourse of Flowers
I perhaps owe having become a painter to flowers. ~Claude Monet
When you have only two pennies left in the world, buy a loaf of bread with one, and a lily with the other. ~Chinese Proverb