When we think if parasites, we usually do not think of plants. It might surprise you, but North Dakota is home to several parasitic plants.
If you have observed what looks like yellow silly string growing among some low growing plants, it was likely dodder (Cuscuta spp.). Dodder is a member of the Morning Glory Family (Convolvulaceae). There are twelve species documented in the state that are known to grow on a variety of plants.
Parasitic plants lack chlorophyll, so they must find some other way to get their energy. They produce copious amounts of very small seeds. Very small seeds provide little energy reserves for germination and seedling growth. So, the young roots of seedlings must quickly tap into a host such as a photosynthetic plant or mycorrhizae, or it runs out of energy and dies. Mycorrhizae, you may recall, are soil fungi that grow into the plant’s roots and supply the plant with water and nutrients in exchange for a steady supply of sugar (mutualism).
North Dakota also has three species of broomrapes (Orobanche spp., Broomrape Family, Orobanchaceae). The species I have seen most frequently is clustered broomrape (O. fasciculata) which often parasitizes fringed sage (Artemisia frigida) and other sages. It is pinkish or perhaps purplish colored and grows to maybe 3-4 inches tall.
Indian pipe or ghost plant (Monotropa uniflora) has been documented in Bottineau, Rolette, Cavalier, Dunn, McKenzie, Pembina, Ransom, and Stark counties. It is a member of the Heath Family (Ericaceae) that grows in rich woods and resembles a small white smoking pipe. The stem is about three inches tall, roughly a quarter of an inch in diameter, and at the top is a single tubular flower pointed slightly downward.
Indian pipe gets its sugars from mycorrhizae, so in this case the sugars probably come from aspen. It looks like the Indian pipe is parasitizing the aspen tree by using the fungus as a conduit.
North Dakota is also home to three species of coralroot orchids. These orchids remind me of peppermint sticks. They are reddish-purplish, about eight inches tall, with small red flowers and pale stripes. Like the Indian pipe, coralroots use the mycorrhizae as a conduit to get the sugars from another plant.
If these relationships sound rather complicated, they are!