"Flower of Asclepias Cornuti. A, entire flower; B, vertical section; C, diagram; D, details of pollen-masses and glands. ca, calyx; c, corolla; hd, hood; hn, horn; a, anther; s, stigma; o, ovary; g, gland; p, pollen-mass." -Bergen, 1896

Milkweed

"Flower of Asclepias Cornuti. A, entire flower; B, vertical section; C, diagram; D, details of pollen-masses…