Miner's Lettuce :

Rooreh, Indian Lettuce
Claytonia perfoliata ssp. perfoliata
NATIVE

Description (Jepson, PlantID.net)

Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
Miner’s Lettuce Family (Montiaceae)
Common annual herb
Leaves
- Fleshy (succulent) leaves
- In 3 sequential forms
  - First sets are blade-shaped
  - Next sets are spade-shaped
  - Finally, a fused pair creates a disk (perfoliate leaf) below the flowers
Flowers
- Inflorescence (flower arrangement) is a terminal raceme (unbranched stem with stalked flowers opening from the bottom up)
- Numerous, small, white to pink flowers
  - Emerge from the center of the perfoliate leaf
  - May or may not have a stalk
  - Small bract (modified leaf) at the base of the lowest flower covers the emerging buds
- Ovary superior (above the attachment of other flower parts)
Fruit is a capsule (a dry, multi-chambered fruit that splits open at maturity)
- Mature capsule breaks open explosively, casting seeds several feet
  - The explosive release of seeds from a fruit is called ballochory
Height to 16 in.

Distribution

Native to California
- Grows in seasonally damp locations in oak woodlands and coastal sage scrub
- See Calflora for statewide observations of this plant
Outside California, confined to western mountain and coastal regions of North America
Grows at elevations to 3,280 ft.

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

Wildlife
- Seeds eaten by birds
Human
- Greens eaten boiled or as salad greens
  - Native people are reported to have placed leaves near red ant nests so that swarming ants would leave a vinegar taste–creating salad dressing! (Corelli 2004)
- Good source of vitamin C
CAUTION – Contains oxalic acid and can be toxic if ingested in large quantities

Name Derivation

Claytonia (klay-TONE-ee-a) – named for John Clayton, an 18th-century American botanist
perfoliata (per-fo-lee-AY-ta) – from the Latin prefix per-, “through,” and folium, “leaf,” as the stem appears to perforate the fused upper leaves
Miner’s lettuce – refers to California Gold Rush miners who ate it to prevent scurvy
Rooreh – Ohlone name

Notes

Happiest in a cool, damp environment; stressed leaves turn deep red
The white, fleshy tips on the seeds are elaiosomes, nutrient-rich food packages that attract ants
- Ants carry the seeds back to their colony, feed the food packet to their larvae, and discard the seed, thus aiding in seed dispersal (Lengyel 2010)
- Giant trillium (Trillium chloropetalum) is another Edgewood species that uses this strategy, called myrmecochory
Edgewood’s miner’s lettuce is classified as a subspecies
- Subspecies indicates a geographically-separated population with distinct morphological characteristics; when not isolated, interbreeding is possible
- Variety indicates a population with small morphological variations, e.g. color, seen throughout the geographic range of the species; interbreeding is possible
- In practice, botanists have not consistently applied these ranks

At Edgewood

Found in woodlands and grasslands
- See iNaturalist for observations of Claytonia perfoliata
Flowers February – May

Specific References

University of California Agriculture and Natural Resources. 2019. Miner’s lettuce. Statewide Integrated Pest Management Program.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.

Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Harris, J.G. and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.

Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.