The Milkweed family, Apocynaceae, contains some of the most spectacular flowers of any plant group. Many species also have interesting relationships with pollinators. For example, the North American Butterflyweed, Asclepias tuberosa, is a critical host plant for the Monarch Butterfly: the butterfly pollinates this species and lays its eggs on the milkweed, which contains a toxic latex sap. Monarch caterpillars have evolved to eat the milkweed leaves and use the toxic chemicals in the sap as part of their own chemical defense system, making them unpalatable to birds and other predators. Other members of Apocynaceae, like Stapelia, have large red and brown flowers that smell like rotting meat: this color scheme and odor attract carrion flies, which pollinate the flower. The list of bizarre and beautiful flowers goes on and on, including the commonly cultivated Amsonia (bluestar), Nerium (oleander), Madevilla, and Hoya (waxflower).
Apocynaceae are found across the globe, but are most diverse in tropical ecosystems. Among the most spectacular ecosystems where Apocynaceae predominate are the Spiny Forests of Madagascar, where the genus Pachypodium looks like a tree straight out of Dr. Seuss. Much like the ecology and floral diversity of Apocynaceae, this family also contains a diverse array of alkaloid and glycoside chemical compounds. These chemicals, although toxic, have been used in the treatment of cancers, eye injuries, and drug addiction, and as ceremonial hallucinogens. By transcribing Apocynaceae specimens from the NYBG herbarium, you are helping scientists better understand the unique ecology and chemical diversity of this amazing family.