Alkali Mallow

Malvella leprosa

White Alkali Mallow flower
Nature Center | July 2011

Alkali mallow (Malvella leprosa) is a widespread California native with soft, gray-green leaves reminiscent of geranium leaves and small hibiscus-like flowers. Alkali mallow flourishes under difficult conditions, such as in alkaline or saline soils and in disturbed areas. It can become a pest in California agricultural areas. In Australia, where it is not native, it is classified as a noxious weed.

Our species is sometimes called marsh mallow, but true marsh mallow is a different, but related species native to Europe, western Asia, and northern Africa. Over 4000 years ago, Egyptians mashed mallow roots into a mucilaginous substance that was sweetened with honey to make the first marshmallows. Egyptians reserved these treats for their gods and nobility.

Other Common Names:

alkali side, dollar weed, ivy-leaf sida, creeping mallow, white mallow, star mallow, whiteweed, marsh mallow

Description 2,4,11,59,183,340

Alkali mallow is a low-growing perennial, up to 13 feet (4 m) across. Stems emerge from deep vertical roots and from long, subsurface rhizomes. Fragmented stems may produce new plants. Stems, foliage and parts of the flowers are densely covered with stiff, white hairs, many of them stellate; these give the plant its gray-green color. Leaves resemble geranium leaves: rounded-kidney-shaped to fan-shaped or triangular with irregularly toothed, wavy margins and palmate veins. The petioles are up to 1½ inches (4 cm) long.  Leaves are usually 1½ inches (4 cm) or less in width and slightly shorter than broad, although in shade they can reach twice that size; they are often distinctly asymmetric at the base.

The bisexual flowers are produced singly or in clusters of two to three in the leaf axils. There are one to three inconspicuous, linear bracts at the stem node; these are often dropped early. There are five sepals fused into a five-lobed tube. The rounded petals are mostly free, forming a wide cup usually 3/4 ” (2 cm) or less across. They are mostly white (pale yellow in some reports). They are asymmetrical, being strongly indented at one side of the base and having one section, the section opposite the indentation, dotted with fine pink dots on the outer surface; this surface is on the outside of the bud and often turns the bud pinkish  The numerous stamens are fused along most of their length into a tube which is fused to the base of the corolla. The free portions of the filaments are of different lengths and arch outward into a rounded display of globular white anthers with white pollen. The superior ovary is obscured by staminal column. There are 6-10 white styles each with a white capitate stigma often difficult to recognize among the anthers. Plants bloom mostly between March and October.1

Fruits are reported to be a dry, disk shape, composed of six – eleven wedge-shaped segments, each with a single seed. Segments break apart at maturity but do not open to release the seed. Mature fruits have not yet been observed in the Reserve and are reported to be rare in other areas59 leading to speculation that, under some circumstances, the primary mode of reproduction may be vegetative by way of the subsurface rhizomes.

white flowers throughout green leaves

Nature Center | July 2011

Alkali Mallow plant

Note pink tinge on bud | Nature Center | July 2011

Basal indentation, pink-tinged section, stigmas, and stamens of split Alkali Mallow flower

Split flower showing basal indentation (top line), pink of section of petal (right), stigmas (bottom), stamens (left) |Nature Center | July 2017

Distribution 2,7,89,183,340

Alkali mallow is native to California and a wide area of western North America, from Washington south into Mexico and east to Idaho and Texas, generally below 5000 feet (1600 m). It is also found in southern South America. It can become an agricultural pest, especially in orchards and pastures. It was introduced into Australia where it is considered a noxious weed.59 It is especially common in alkaline or somewhat saline soils and in disturbed areas

In California, alkali mallow is especially common in the Central Valley and along the southern coast.

There are two populations of alkali mallow in the Reserve. One is near the east end of the Reserve, near the La Orilla trailhead where the trail runs beside the marsh with bulrush and cattails. The other is at the Nature Center, on the south side of the vegetated area around the patio.

Classification 2,11,143

Alkali mallow is a dicot angiosperm in the mallow family (Malvaceae). The typical mallow has numerous stamens with the filaments united into a tube around the pistil, and the anthers sprayed out in a pom-pom at the top. Flowers are typically associated with one to many small, leaf-like bracts. Leaves have palmate veins and may be palmately lobed. Plants are often covered with small, white stellate hairs. The fruit is variable but is often a disk composed of one-seeded, wedge-shaped sections, often likened to a wheel of cheese. Many plants contain natural gums, which can be whipped into a froth.

There are several well known species of mallow, including the garden flowers hollyhock (Alcea spp.) and hibiscus (Hibiscus spp.), the vegetable okra (Abelmoschus esculentus), a staple of Cajun cooking and cotton (Gossypium spp.), one of our most valuable agricultural crops. The plant that was first used to make marshmallows (Althaea officinalis) also belongs to this family.

There are five species of mallow reported from the Reserve.48 In addition to alkali mallow, there are three native species: chaparral mallow (Malacothamnus fasciculatus), checkerbloom, (Sidalca sparsifolia) and the endangered island mallow, or malva rosa (Malva assurgentiflora). Cheeseweed (Malva parviflora) is introduced.

Malvella is a small genus, distinguished from other genera in the mallow family by characteristics of the stigmas, stamens and fruit.

Alternate Scientific Names:

Cressa insularis Cressa depressa

Jepson eFlora Taxon Page
Flower of Alkali Mallow

Nature Center | September 2010

Small green node under microscope

Stem node with line indicating small bract | Nature Center | July 2017

Green leaf with rippled edges

Nature Center | July 2017

Ecology 41,217,351

The hairs, or trichomes, of most mallows may have several adaptive values. They may protect the leaf from heat and sun and directly or indirectly from water loss. They may also protect against grazers. Alkali mallow is toxic to sheep, and possibly other animals, because the stiff, stellate trichomes form hairballs that block the intestine of the consumer.183 This may, in turn lead to the general avoidance of alkali mallow by large grazers.183

Stellate hairs on Alkali Mallow stem

Parts of the plant are covered with stiff white hairs, many stellate | Nature Center | July 2017

Alkali Mallow plant

Nature Center | July 2009

Leaf of Alkali Mallow

Nature Center | July 2017

Human Uses  

The Luiseño used the leaves of alkali mallow as an emetic.

Alkali mallow is an attractive ground cover, but we can find no recommendations for its use in native plant gardens, perhaps because of its aggressive growth and invasive tendencies.

Alkali Mallow plant

Nature Center | July 2009

Flower of Alkali Mallow

Nature Center | July 2017

Flower of Alkali Mallow

Nature Center | July 2009

Interesting Facts 41,352

Alkali mallow is occasionally called marsh mallow, but the true marsh mallow is a related species from Europe, western Asia, and northern Africa. The familiar marshmallow was created around 2000 BC when the Egyptians boiled pieces of marsh mallow root pulp with sugar and water until thickened. This was strained and cooled and consumed by nobility and Pharaohs and offered to the Gods. It was a crime for anyone else to eat this treat. The Greeks and Romans thought that marshmallows had curative properties and marshmallows were a part of Hippocrates’ medical remedies.

Through the centuries the marshmallow has been modernized, first updating the ingredients (the basics now consist of sugar, water and gelatin, often coated with corn starch) and then automating production. Marshmallows are revered around the camp fire, but do they still appease the Gods?

Unopened flower bud of Alkali Mallow

La Orilla trailhead | July 2017

Closeup of Alkali Mallow flower

Nature Center | July 2017

Flower of Alkali Mallow

Nature Center | July 2009

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