Cancer-root
Aphyllon uniflorum
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CLASSIFICATION: What’s in a name?
Scientific Name: Aphyllon uniflorum. The genus Aphyllon is derived from the Greek word for leaf, phyllon, and means “without leaves”, referring to the fact that this parasitic species does not produce foliage (or even photosynthesize!). The epithet uniflorum means “one-flowered” in Latin, since each stem bears a single flower. This species was formerly known as Orobanche uniflora.
Common Name: The most widely used common name, cancer-root, is likely derived from its parasitic nature. Other common names include one-flowered broomrape, naked broomrape, and ghost pipes.
Family: Orobanchaceae (Broomrape family). This is a family of partially or wholly parasitic plants, the latter of which do not produce chlorophyll and have only vestigial leaves. The flowers are bilaterally symmetrical and typically have 5 petals. Fruit is a dry capsule.6
IDENTIFICATION: What does it look like?
Average Height: 3 to 8 inches.
Description: A perennial spring ephemeral plant with no leaves or chlorophyll, bearing one or several upright stems from an underground stem. Each of these above ground stems is topped with a single flower, which is a pale whitish or bluish color and has five petals. After flowering, the flower becomes an oval seed capsule before setting seed and going dormant in late spring. Since it doesn’t photosynthesize, this plant only pops above ground to reproduce!
Bloom time: Apr-May2
Notes: This species does not produce chlorophyll, the pigment used for photosynthesis. Instead, it derives its nutrients through parasitism. Specialized structures on the roots called haustoria tap into the roots of a suitable host plant, and siphon off some of its nutrients. Many species can serve as hosts for cancer-root, including goldenrods (Solidago spp.), sunflowers (Helianthus spp.), and saxifrages (Micranthes spp.)1
‘LOCATION: Where is it at home?
Range: Widespread in Virginia, uncommon to fairly common (though inconspicuous!) in the Mountains and Valleys and Piedmont, and rare in the Coastal Plain. Documented in 45 states as well as several Canadian provinces.3,4
Geology/Soil: Found in many types of soils, from sandy to loamy, acidic to calcareous.
Habitat: A wide variety of forests, including rich floodplain forests and slope forests, rocky bluffs and woodlands, and dry, nutrient-poor uplands.1,4,5
CONNECTIONS: What are its relationships to other plants, animals, and humans?
Flora associations: At Riverview Park, this species can be found growing with other spring ephemerals such as spring beauty (Claytonia virginica var. virginica), yellow trout lily (Erythronium americanum ssp. americanum), mayapple (Podophyllum peltatum), and lanceleaf anemone (Anemone lancifolia), as well as suitable host plants such as early saxifrage (Micranthes virginiensis) and blue-stemmed goldenrod (Solidago caesia).
Fauna associations: The flowers are pollinated by bumblebees including the North American bumblebee (Bombus pensylvanicus).1
Human associations: none found.
We want these plants to thrive and for everyone who gets to visit the park to enjoy them, so remember – don’t pick flowers or other parts of the plant!!
Bibliography & Definitions
1 “One-Flowered Broomrape (Orobanche Uniflora).” Www.illinoiswildflowers.info, www.illinoiswildflowers.info/woodland/plants/of_broomrape.htm. Accessed 1 Mar. 2024.
2 Weakley, A.S., J.C. Ludwig, and J.F. Townsend. 2012. Flora of Virginia. Bland Crowder, ed. Foundation of the Flora of Virginia Project, Inc., Richmond. Fort Worth: Botanical Research Institute of Texas Press, , pp. 1155-1157.
3 “Orobanche Uniflora – FNA.” Beta.floranorthamerica.org, beta.floranorthamerica.org/Orobanche_uniflora. Accessed 1 Mar. 2024.
4 Virginia Botanical Associates. “Digital Atlas of the Virginia Flora | Aphyllon Uniflorum L.” Www.vaplantatlas.org, www.vaplantatlas.org/index.php?do=plant&plant=3088&search=Search. Accessed 1 Mar. 2024.
5 LeGrand, Harry, et al. “Vascular Plants of North Carolina.” Ncparks.gov, 2019, auth1.dpr.ncparks.gov/flora/plant_list.php.
6 Native Plant Trust. “Family: Orobanchaceae (Broom-Rape Family): Go Botany.” Gobotany.nativeplanttrust.org, gobotany.nativeplanttrust.org/family/orobanchaceae/.
Definitions:
Spring ephemeral: A perennial plant which grows early in the spring – before the trees grow leaves – to take advantage of the sunlight reaching the forest floor. In less than 2 months, the plant grows, blooms, and produces seed and then disappears from view as the leaves die back.