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Bear Corn

Conopholis americana

Summary 4

Conopholis americana, American cancer-root or squawroot or bear corn, is a perennial, non-photosynthesizing (or "achlorophyllous") parasitic plant, from the family Orobanchaceae and more recently from the genus Conopholis but also listed as Orobanche, native but not endemic to North America and when blooming, resembles a pine cone or cob of corn growing from the roots of mostly oak and beech trees.

Comments 5

This parasitic plant looks like a mutant pine cone or something from a horror movie. Its closest relatives are Orobanche spp. (Broomrapes), which are also parasitic and uncommon. The species Orobanche ludoviciana (Prairie Broomrape) has a similar appearance with thick white spikes of flowers, but the corollas of its flowers are usually tinted lavender or pale purple and they are longer (about ¾" in length). Another common name of Conopholis americana is Squawroot.

Description 6

This native perennial plant is 3-8" tall and unbranched. It consists of a rather thick spike of flowers, while the leaves are reduced to scales. During the late spring this spike is cream-colored and hairless. Underneath each flower, there is an ovate scale up to ½" long that quickly turns brown. The flowers bloom during the late spring or early summer for about 3 weeks. They are densely crowded all around the spike, and begin to bloom from the bottom to the top. Each flower is about ½" long, consisting of a tubular corolla and a tubular calyx. Both the corolla and calyx are cream-colored, although the teeth of the calyx soon turn brown and wither away. The rest of the calyx wraps around the base of the corolla. The corollas of young flowers are initially semi-erect, but they spread outward from the spike with age. Each corolla has a convex upper lip that functions as a hood, while the poorly defined lower lip is smaller in size. Within the corolla, there are 4 stamens near the interior of the upper lip, and a single stout style that develops along the lower lip. Both the style and filaments of the stamens are white, while the anthers are grey. When the flowers are blooming, some of the stamens and styles may be exerted from their corolla tubes. There is no noticeable floral scent. Each flower is replaced by a seed capsule containing many small seeds; this seed capsule is longer than it is wide. As the summer progresses, the flowering spike begins to wither and becomes brown. It can persist through the winter, by which time it has become shriveled and black. The root system is parasitic on the roots of Quercus spp. (Oak Trees); the suckers of the parasitic roots cause the formation of large rounded knobs on the roots of the host tree. Because Cancer Root doesn't produce chlorophyll, it is dependent on the host tree for its nourishment. Small clusters of flowering spikes often develop from the same root system. This plant spreads to new locations by reseeding itself.

Sources and Credits

  1. (c) Janet, some rights reserved (CC BY-NC-SA), http://www.flickr.com/photos/55854130@N00/487650505
  2. (c) Fritz Flohr Reynolds, some rights reserved (CC BY-SA), https://www.flickr.com/photos/fritzflohrreynolds/8695212198/
  3. (c) The Natural Capital, some rights reserved (CC BY-NC-SA), https://www.flickr.com/photos/39049716@N04/4553224806/
  4. Adapted by Jonathan (JC) Carpenter from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Conopholis_americana
  5. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/29445123
  6. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/29445119

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