Yerba mansa

Anemopsis californica

"myriads of white stars..." | Photo credit: Jennifer Bright | Penasquitos Canyon Preserve | June 2000

Just as the fervid glow of the sun is beginning to transform the green
of our southern hill-slopes to soft browns, the still vividly green lowland
meadows suddenly bring forth myriads of white stars, which in their
green setting become grateful resting-points for the eye.

These are the blossoms of the famous yerba mansa of the Spanish-Californians.
Among these people the plant is an infallible remedy for many disorders,
and so highly do they prize it that they often travel or send long distances for it.

(Parsons, ³⁹⁹ )

Other Common Names:

Swamp root, lizard's tail, bear root

California Taxon Report

Description ^4,11,34,59

Yerba mansa (Anemopsis californica) is a unique-looking perennial herb, that often forms large mats from horizontal stems (stolons and rhizomes) that spread at or just below ground level. Clumps of leaves are produced and root at discrete nodes along these stems (much like a strawberry plant). Leaves may stand two or three feet (75 cm) high, but are usually shorter. Long petioles support oval or elliptical blades, that are smooth, almost rubbery in appearance. Older leaves may develop splotches of rose. All parts of the plant are aromatic. The scent has been described as “a cross between Camphor and Eucalyptus”,²⁹³ “deep, woody”²⁷² and “spicy”.⁴¹ The precise aroma varies. One patch in the Reserve gave off a peppery scent, reminiscent of nasturtium.

Leaves surround a vertical stalk supporting one (sometimes more) dense, conical inflorescences composed of a hundred or more tiny flowers. At the base of each cluster is a ring of five to eight large petal-like bracts, white sometimes blotched with rose; these protect the developing inflorescence and, when open, give the entire cluster the appearance of a single flower. The component flowers are difficult to interpret because the bases of the flowers are sunk into the tissue of the supporting stem and individual flowers do not separate easily, either physically or visually. There are no sepals or petals. Each tiny flower consists of six stamens and one pistil with an inferior ovary and a style with three linear branches that curve outward when mature. Below each tiny flower is a single small, white oblong bract (or bractlet), ¼ inch or less (0.6 cm) wide. In a young inflorescence, the many small bractlets are often the most striking feature. Flowers bloom between March and September.⁴⁶⁸

Each tiny flower produces a few small seeds. As they mature, the numerous flowers become a dense, solid structure embedding hundreds of tiny seed capsules. These split open from the top, releasing seeds. The entire inflorescence may occasionally act as a dispersal mechanism, floating away with high water to drop its seeds elsewhere.⁴¹

Distribution ^{7,34,41,89,306}

Yerba mansa is native to southwestern North America, from Oregon to northern Mexico and Baha California, east to Texas and Kansas.⁸⁹ It is a plant of damp, boggy areas, and tolerates both salinity and alkalinity.³⁰⁶ In California, it is common in wet areas from the coast to the desert, primarily south of San Francisco and below 6000 feet. It is likely to have been more common in southern California before development eliminated many of our wetter areas.

Yerba mansa is not common in the Reserve (which helps to explain why most of these photos were obtained at nearby Los Peñasquitos Canyon Preserve). At present (2024), there is one patch under the willows along the Nature Center loop trail, and for a couple of years there was a small patch near the Rios trailhead, possibly facilitated by a small seep from adjacent houses. Recently, a patch appeared in the willows along Manchester Ave, in the Cardiff Cove area. Yerba mansa was planted in the restoration area west of La Orilla where patches can be seen along the trail, peeking out below mugwort, ambrosia and wild rose. It has also been planted in restoration areas along Escondido creek.

Classification ^2,8,11,41,59

Yerba mansa (Anemopsis californica) was formerly placed within the dicot angiosperms, but recent revisions to the traditional taxonomy have separated yerba mansa along with other more primitive plants into a group, the primative dicots or basal dicots. This is distinct from the rest of the dicots (now called eudicots) and from the monocots. The precise classification is changing as more information is acquired.

Yerba mansa is in the lizard’s tail family (Saururaceae) a very small family of three genera and six species.It is the only representative of the primative dicots known in the Reserve.

The family also includes Saururus cernuus, a plant native to the eastern United States that is commonly known as lizard’s tail. Its inflorescence, is long, slim and curved at the end – perhaps like a lizard’s tail. This is presumed to be the source of the family name.

Jepson eFlora Taxon Page

Ecology ^515,516

Self-pollination of yerba mansa is genetically blocked. A pollen grain that lands on a pistil of the same plant will not develop. This self-incompatibility is an extreme adaptation to ensure cross-fertilization, which, in turn, promotes genetic diversity, population health and survival, and – ultimately – evolution. Thus the success of self-incompatibility depends upon cross-pollination – the receipt of pollen from other plants; in areas or during times of low plant abundance, or low numbers of pollinators, seed production could cease entirely.

Vegetative reproduction is one adaptation to ensure survival and growth during times when cross-pollination is restricted. The system of stolons and rhizomes of yerba mansa produce large patches of identical individuals without pollination. However, as the size of such a patch increases, the distance to plants near the patch center increases and the efficiency of pollen input from genetically different plants diminishes.

Self-incompatibility and clonal reproduction appear to be opposing forces, and yet they co-occur in many plant groups. Populations of these plants, like yerba mansa, appear to be stable over the long term. Apparently, a balance has been achieved, with cross-pollination and rhizomal growth teeter-tottering back and forth over time.

Human Uses ^{15,17,67,272,282}

Throughout local history, yerba mansa has been one of the most widely used plants, first by native Americans, then by early settlers and currently by followers of homeopathic medicine. Many cultures are thought to have moved this plant around, establishing new colonies more convenient for use.

Historically, yerba mansa was been used by all the tribes in whose territory it grew.¹⁵ In spite of the number of reported applications, it does not seem to have been used for food (although seeds may have been used as a substitute for pepper).¹¹ It was applied externally for sores and cuts and rheumatism and internally for coughs, asthma and kidney problems; it was drunk as a blood purifier. The Chumash used it to purify and prepare a person for handling dangerous substances to be used in ceremonies,¹⁵ and the Kumeyaay carried a bit of root in a pouch for luck.²⁷²

Today, several sources list yerba mansa extracts and powders for sale on the web, although their advertised effects have not been verified scientifically. ⁴⁸²

Interesting Facts

The common name, yerba mansa, is a bit of a puzzle. Technically, it translates from the Greek words for “tame”and “anemone”. But this suggests it has calming (taming) properties and it does not.⁴¹ Some believe the current name was shortened from yerba del manso or “herb of the tame Indian”.²³ A third explanation is that the word “manso” has been shortened from “remanso” which means “backwater”, making the original name yerba remanso or “herb of the backwater” which describes its habitat rather well. ⁴¹