California Manroot :

Wild Cucumber
Marah fabacea
NATIVE – CA ENDEMIC

Description (Jepson, PlantID.net)

Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
Gourd Family (Cucurbitaceae)
Perennial, herbaceous, tendril-bearing vine
- Grows from a large tuberous root
Large leaves are palmately lobed (lobes radiating from a single point)
Flowers
- Star-shaped, white to cream-colored, fragrant flowers, with 5 fused petals
- Separate male and female flowers on the same plant (monoecious)
  - White male (staminate) flowers in a raceme (unbranched stem with stalked flowers opening from the bottom up) or panicle (branching stem with flowers opening from the bottom up)
  - Larger, solitary female flowers at the leaf axil (branching point)
- Ovary inferior (below the attachment of other flower parts)
Fruit is a spherical, golf-ball-sized capsule (a dry, multi-chambered fruit that splits open at maturity) covered with straight prickles (extensions of the epidermis), containing 4 or more large seeds
- Internal pressure builds in the mature capsule, splitting and expelling seeds
- The explosive release of seeds from a pod is called ballochory
Vine extends to 20 ft.

Distribution

Native and endemic (limited) to California
- Most widespread Marah species in California, found within the range of almost all other native manroot species
- Grows in woodlands and chaparral with seasonally moist soil
- See Calflora for statewide observations of this plant
Grows at elevations to 5,250 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

Wildlife
- Nectar source for the green hairstreak butterfly (Callophrys rubi)
Native people
- Roots used for fishing
  - Crushed roots were thrown in slow-moving creeks or pools to stun fish, aiding in their capture (Sigg 2012)
  - Soap-like saponins in the roots enter through the gills and interfere with oxygen absorption and transport (Rosenthal 2014)
  - Fruits of California buckeye (Aesculus californica) and common snowberry (Symphoricarpos albus var. laevigatus) and the bulbs of soap plant (Chlorogalum pomeridianum var. pomeridianum) were similarly used for fishing
- Seeds used for decoration or ground to make face paint/mascara
- To prevent baldness, the Kashaya Pomo applied to the scalp a mixture of the pounded raw root, pounded California bay fruit, and skunk grease (Native American Ethnobotany)
CAUTION – all parts of plant are POISONOUS
- The alternative common name, wild cucumber, may suggest a similarity to the familiar edible cucumber (Cucumis sativus); however, Marah fabacea is NOT EDIBLE
- Liquid inside fruit is an eye irritant
- Use caution if handling the dried fruit as prickles may irritate the skin

Name Derivation

Marah (Mar-ah) – from the Hebrew for “bitter,” likely a biblical reference to Marah, a place with undrinkable water visited by the Israelites during the Exodus; here, referring to the plant’s bitter taste
fabacea (fab-AY-see-a) – from the Latin for “broad bean”
Manroot – referring to the mature tuber, which can be as large as a man’s torso

Notes

Plant appears following winter rains, then dies back completely, becoming dormant during the dry summer and fall months
Long tendrils enable plant to climb/trail over vegetation
Once a tendril curls around a support, it forms a counter-clockwise helix and clockwise helix with a straight section between the two. If the tendril is pulled, more turns are added to both helices to better grasp the support (Perry 2012)
A mature tuber can be several feet in diameter, weighing over 150 lbs., with swollen lobes and arm-like extensions
- The root of a Marah macrocarpa at Rancho Santa Ana Botanic Garden weighed 467 lbs.
- The Coast Guard has investigated reports of floating bodies that proved to be large manroot tubers (Marah species), fallen into the ocean from eroded coastal bluffs (Breckling 2008)
Pollinated by insects but can also self-pollinate

ID Tips

At Edgewood

Found in chaparral and woodlands
- See iNaturalist for observations of this plant
Flowers March – April

Specific References

Breckling, B. 2008. Spring Wildflowers of Henry W. Coe State Park and the Inland San Francisco Bay Area. Pine Ridge Association.

Perry, C. 2012, Aug. 30. Uncoiling the cucumber’s enigma. News & Events. School of Engineering and Applied Sciences, Harvard University.

Rosenthal, S. 2014, Jan. 13. The many uses of spring-blooming soaproot. Bay Nature.