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American Cancer-root Conopholis americana

Other Common Name(s):

Previously known as:

  • Conophlis Alpina
Phonetic Spelling
koh-noh-FOH-lis a-mer-ih-KAY-nah
Description

Cancer Root is an herbaceous, perennial, parasitic plant in the boomrape (Orobanchaceae) family. It typically grows from 3 to 8 inches in height, an inch wide, and is unbranched. Inflorescences that look like the cones from a conifer break through the surface of the soil when the plants are approximately four years old after they have been growing underground attached to oak roots. As it matures, the plant produces a rather thick spike of flowers, while the leaves are reduced to scales. The spike is cream-colored and hairless in late spring and the flowers bloom from the bottom to the top of the spike for a short time in spring and summer. As the summer progresses, the flowering spike withers and becomes brown and resembles a pine cone as it becomes dry with age. The genus name Conopholis comes from Latin for 'cone' and 'scale' and refers to the appearance of the stems with scale-like flowers that resemble upright golden cones. Despite the common name, there is no evidence that the plant has anything to do with cancer. 

Cancer Root grows in large areas of Eastern America on organically rich forest soils.  It needs well-drained soils but grows in a wide variety of light conditions. This plant does not photosynthesize, hence its lack of the green pigment chlorophyll. 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. Black Bears coming out of hibernation forage on the flowering spikes and there is some evidence that deer browse on the spikes occasionally. It is possible that such animals may help to disperse the seeds to new locations.

Diseases, Insect Pests, and Other Plant Problems:

No known diseases or insect pests.

 

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#gold#slow growing#scales#NC native#summer flowers#spring interest#parasitic#woodland
 
Cultivars / Varieties:
Tags:
#gold#slow growing#scales#NC native#summer flowers#spring interest#parasitic#woodland
  • Attributes:
    Genus:
    Conopholis
    Species:
    americana
    Family:
    Orobanchaceae
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    E. Canada, Central & E. U.S.A., S. Mexico, Costa Rica to Panama
    Distribution:
    Every state east of the Mississippi, Canada.
    Wildlife Value:
    Forage for bears and deer.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Native Plant
    Wildflower
    Habit/Form:
    Erect
    Growth Rate:
    Slow
    Maintenance:
    Low
  • Cultural Conditions:
    Light:
    Dappled Sunlight (Shade through upper canopy all day)
    Deep shade (Less than 2 hours to no direct sunlight)
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    High Organic Matter
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Dry
    Available Space To Plant:
    Less than 12 inches
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Type:
    Capsule
    Fruit Description:
    Each flower is replaced by a seed capsule containing many small seeds; this seed capsule is longer than it is wide.
  • Flowers:
    Flower Color:
    Cream/Tan
    Gold/Yellow
    Flower Inflorescence:
    Spike
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Spring
    Summer
    Flower Shape:
    Tubular
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    < 1 inch
    Flower Description:
    Cream to golden yellow spike inflorescences densely packed around erect stems resembles cones or cobs of corn. These appear as early as April in warm areas or as late as July and bloom for a period of about three weeks. Tubular flowers are 1/2" long, 5 parted, are downward facing and have a swollen base. Flowers bloom from the bottom of the spike to the top.
  • Leaves:
    Leaf Color:
    Brown/Copper
    Gold/Yellow
    Leaf Shape:
    Lanceolate
    Ovate
    Hairs Present:
    No
    Leaf Length:
    < 1 inch
    Leaf Description:
    No true leaves, brown ovate 1/2 inch long scales appear underneath each flower. Flowers emerge among the lanceolate or ovate, pointed, yellow-tan scales on upper part of a fleshy stalk.
  • Stem:
    Stem Is Aromatic:
    No
    Stem Description:
    Thick (1/2 inch - 1 inch) stout unbranched stems.
  • Landscape:
    Landscape Location:
    Woodland
    Landscape Theme:
    Native Garden