Conopholis americana, the American cancer-root, bumeh or bear corn, is a perennial,[3] non-photosynthesizing (or "achlorophyllous") parasitic plant. It is from the family Orobanchaceae and more recently from the genus Conopholis but also listed as Orobanche, native but not endemic to North America. When blooming, it resembles a pine cone or cob of corn growing from the roots of mostly oak and beech trees.[4][5]

Conopholis americana

Secure (NatureServe)
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Lamiales
Family: Orobanchaceae
Genus: Conopholis
C. americana
Binomial name
Conopholis americana
Range of Conopholis americana

Orobanche americana L.[2]

Description Edit

Conopholis americana is parasitic on the roots of woody plants, especially oaks (genus Quercus) and beech (genus Fagus).[3] The only part of the plant generally seen is the cone-shaped inflorescence,[5] which appears above ground in spring.[6] The entire structure is a yellowish color, turning to brown.[3] It achieves heights of 10 centimeters (4 in) to 20 centimeters (8 in) tall.[7]

Stems and leaves Edit

The plant has stout and unbranched 1.3 centimeters (0.5 in) to 2.5 centimeters (1 in) thick stems.[8] Since C. americana does not photosynthesize[5] it also does not have true leaves; it has instead simple, ovate, tiny scales[3] 1.3 centimeters (0.5 in) long and brown, which appear at the base of each flower.[7]

Flowers Edit

Conopholis americana produces spikes of yellow to cream flowers densely crowded all around the stem.[7] Each flower is 5-parted, 8 millimeters (0.3 in) to 13 millimeters (0.5 in) long, tubular with a swollen base and facing downwards.[8] As the flowering spike matures it begins to wither and becomes brown throughout the summer and often persisting through the winter, by which time it has become shriveled and black. There is no noticeable floral scent.[7]

Fruits and reproduction Edit

Each flower is replaced by a seed capsule that is longer than it is wide and contains many small seeds. This plant spreads to new locations by reseeding itself.[7]

Roots Edit

The root system is parasitic on the roots of oak trees (Quercus spp.); dependent on the host tree for its nourishment, the suckers of the parasitic roots cause the formation of large rounded knobs on the roots of the host tree.[7]

Distribution Edit

The plant is found growing on roots in wooded ravines[3] in every state of the United States east of the Mississippi River.[1] While widely distributed, it is uncommon.


Northern America:
Eastern Canada: Nova Scotia, Ontario, Quebec
Northeastern U.S.A.: Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia
North-Central U.S.A.: Illinois, Wisconsin
Southeastern U.S.A.: Alabama, Delaware, Florida, Georgia, Kentucky, Maryland, North Carolina, South Carolina, Tennessee, Virginia[2]

It is considered an exploitably vulnerable species in New York, a threatened species in New Hampshire and a special concern in Rhode Island.[1]

References Edit

Conopholis americana in beech/oak forest in northern Florida
  1. ^ a b c Natural Resources Conservation Service (NRCS). "PLANTS Profile, Conopholis americana". The PLANTS Database. United States Department of Agriculture. Retrieved 2008-04-13.
  2. ^ a b "Conopholis americana". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture. Retrieved 2008-04-13.
  3. ^ a b c d e David Ketzner and Jeanne Karnes. "ILPIN INFORMATION ON Conopholis americana". ILLINOIS PLANT INFORMATION NETWORK. United States Forest Service. Retrieved 2008-04-13.
  4. ^ Grafton, Emily. "Beech Drops" (PDF). PNPS Notes Quarter #4. Pennsylvania Native Plant Society. 8. Archived from the original (PDF) on February 21, 2007. Retrieved 2008-04-10.
  5. ^ a b c C. Vandaveer (2005-06-27). "Plant of the Week". Archived from the original on 2007-10-24. Retrieved 2008-04-10.
  6. ^ "Squawroot Conopholis americana". Connecticut Wildflowers. Connecticut Botanical Society. 2008-03-07. Retrieved 2008-04-13.
  7. ^ a b c d e f Hilty, John. "Cancer Root (Conopholis americana)". Illinois Wildflowers.
  8. ^ a b University of Wisconsin–Stevens Point. "Conopholis americana (L.) Wallr". Robert W. Freckmann Herbarium. Archived from the original on 2011-07-24. Retrieved 2008-04-13.

External links Edit

Illustration from 1913