North America Native Plant

Mexican Cancer-root

Botanical name: Conopholis alpina var. mexicana

USDA symbol: COALM

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Conopholis mexicana A. Gray ex S. Watson (COME7)  âš˜  Orobanche multiflora Nutt. var. xanthochroa (A. Nelson & Cockerell) Munz (ORMUX)  âš˜  Orobanche xanthochroa A. Nelson & Cockerell (ORXA)   

Mexican Cancer-Root: A Mysterious Native Parasite You Won’t Be Growing If you’ve ever stumbled across odd, cone-like growths popping up from the forest floor in the Southwest and wondered what on earth is that thing?—you might have encountered Mexican cancer-root. This unusual native plant is definitely not your typical garden ...

Mexican Cancer-Root: A Mysterious Native Parasite You Won’t Be Growing

If you’ve ever stumbled across odd, cone-like growths popping up from the forest floor in the Southwest and wondered what on earth is that thing?—you might have encountered Mexican cancer-root. This unusual native plant is definitely not your typical garden center find, and for good reason!

What Exactly Is Mexican Cancer-Root?

Mexican cancer-root (Conopholis alpina var. mexicana) is one of nature’s more peculiar characters. This perennial forb belongs to a group of plants that have completely abandoned the whole making your own food through photosynthesis thing. Instead, it’s what botanists call an obligate parasite—it survives entirely by tapping into the root systems of oak trees.

Don’t let the somewhat alarming common name worry you—it has nothing to do with the disease. The name likely comes from the plant’s clustered, tumor-like appearance when it emerges from the ground.

Where You’ll Find This Odd Native

Mexican cancer-root is native to the southwestern United States, calling Arizona, Colorado, New Mexico, and Texas home. It thrives in oak woodlands and forest understories where it can find its preferred hosts.

Why You Won’t Be Adding This to Your Garden Wishlist

Here’s the thing about Mexican cancer-root—you literally cannot grow it in your garden, no matter how much you might want to add this conversation starter to your landscape. As an obligate parasite, it requires a living oak tree host to survive. Without that specific relationship, it simply cannot exist.

The plant appears as yellowish-brown to reddish-brown cone-like structures that emerge from the soil, typically measuring a few inches tall. While certainly unique, it’s not what most people would call traditionally beautiful or ornamental.

Its Role in Nature

Although Mexican cancer-root might seem like a botanical freeloader, it plays its part in the ecosystem. Its flowers, small though they may be, can provide nectar for various small insects. However, detailed information about its specific wildlife benefits remains limited.

Native Alternatives for Your Southwestern Garden

If you’re gardening in the Southwest and want to support native plants, consider these wonderful alternatives that you can actually grow:

  • Desert Marigold (Baileya multiradiata) – bright yellow flowers that bloom almost year-round
  • Penstemon species – tubular flowers that hummingbirds adore
  • Desert Willow (Chilopsis linearis) – orchid-like blooms and graceful form
  • Blanket Flower (Gaillardia pulchella) – colorful, drought-tolerant perennial

Appreciating the Unusual

While you won’t be planting Mexican cancer-root in your backyard, encountering it in the wild is a special treat for plant enthusiasts. It’s a reminder that nature is full of surprising strategies for survival, even if they seem a bit unconventional to us.

If you’re hiking in oak woodlands across the Southwest and spot these mysterious cone-like growths, take a moment to appreciate this unique native species. Just remember—it’s perfectly content where it is, doing its parasitic thing, and definitely doesn’t need to come home with you!

Mexican Cancer-root

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Scrophulariales

Family

Orobanchaceae Vent. - Broom-rape family

Genus

Conopholis Wallr. - cancer-root

Species

Conopholis alpina Liebm. - alpine cancer-root

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA