September EcoQuest - Pinedrops, alien or plant?
Every fall, photographs of one plant are always sent to researchers at Denver Botanic Gardens for identification – pinedrops or Pterospora andromedea. These alien-like plants are so weird looking and eye-catching on the forest floor, people can’t help but wonder what they are! Pinedrops have no green coloration in any part of the plant, and thus do not make any of their own food through chlorophyll and photosynthesis. How to these plants obtain the nutrients for survival then? Well, they parasitize the mycorrhizal fungi that are attached to the roots of pine trees!
Many species of trees are associated with mycorrhizal fungi, and the two have a mutually beneficial relationship. The fungi receive carbohydrates and other nutrients from the pine tree, while the pine trees receive an increase in their root surface area and are thus able to secure more water and minerals. Pinedrops tap into these fungal mycorrhizae and obtain all the nutrients, carbohydrates, and water they need to survive, offering nothing to the fungi in return for this supply of food. Pinedrop seeds are tiny and dust-like, also requiring a mycorrhizal association for germination to occur. As the seeds of pinedrop germinate, its roots become encased in the hyphae of the mycorrhizal fungus.
Pinedrops are a member of the Ericaceae, or heath family. They exhibit the characteristic urn-shaped corollas present in many members of the heath family, including blueberries (Vaccinium). Pinedrops also have a sticky, glandular, reddish stem. The scientific name for pinedrops comes from the Greek “Pterospora” meaning winged seed and “andromedea”, a reference to the nodding flowers that are similar to the flowers of Andromeda polifolia. The fruit of pinedrops is a hanging, brownish capsule.
See if you can locate some Pterospora andromedea and help Denver Botanic Gardens by photographing as many plants as possible in the month of September. Post your findings to iNaturalist so they will automatically be added to the Denver EcoFlora Project.
