Petals, by James Sowerby (1757-1822) from A botanical drawing-book, or, An easy introduction to drawing flowers according to nature. First published in 1788. (image to the left rearranged from the original configuration, below)
“The author having experienced the want of a drawing-book sufficiently accurate to enable young beginners, who are fond of delineating flowers, to distinguish the different parts absolutely necessary to characterize each plant, he has been induced to offer a few designs to the public, in order to facilitate botanical studies, and blend amusement with improvement.”
1. Round, nearly round or Orbicular; 2. Oblong, as in many flowers; 3. Heart-shaped or Cordate, with points downwards as Roses &c.; 4. Nearly Triangular, as Mallow &c.; 5. Twisted, as in the Dog’s Tooth Violet &c.; 6. The Four Petals of a Butterfly-like or Papilionaceous, Corolla. (a) the upright Petal, Standard, or Vexillum; (b) the Wings, Side petals or Alae; (c) the keeled, lower Petal, or Carina; 7. The Unguis and Lamina distinct, as in the Stock or Wall Flower. (d) Unguis; (e) Lamina; 8. The same in the Pink or Dianthus; the Lamina notched, or serrated; 9. Two Petals of a Compound Flower. (f) the Centre; (g) the Radius; 10. Two other Florets often compounded in a similar manner; 11. A Petal split, or cloven, as in Chickweed.