Milkmaids

Milkmaids (Cardamine californica) are flowers of early spring, puffs of pale pink color floating among green polypody and yellow sea dahlias on the slopes above Central Basin.

Milkmaids belong to mustard family, along with our native jewel weed and wall flower, and the invasive black mustard and wild radish. Like other mustards, they have four petals in a cross shape and six stamens, four long and two short. Like many mustards, their seedpods are long, thin, dry cylinders.

In spite of the similar names, milkmaids are not related to the Indian spice cardamom.

Description ^2,4,59

Milkmaids are perennial herbs, usually less than 2 feet (60 cm) high that grow from short, thick, horizontal rhizomes.  One or more basal leaves and one or more upright stems grow directly from a rhizome. Basal leaves have one to three rounded leaflets on short petioles; cauline leaves are sparse and are pinnately divided into three to five leaflets. Leaflets of lower leaves are rounded (similar to the basal leaves); further up the stem, leaflets become narrower, with toothed margins and sharply pointed tips. The terminal leaflet of a leaf is generally larger. There is regional variability in the number and shape of leaflets.

Flowers form a loose terminal cluster. Flowers are symmetrical, white to pale pink/lavender, about 1/2 inch (1.6 cm) in diameter with four sepals and four petals.  The petals are rounded with an elongate base (invisible beneath the sepals). There are six stamens, two shorter than the others. The pistil consists of a cylindrical green ovary, about as long as the longer stamens, a green style, and a paler, capitate stigma. The reported flowering period is Feb. – May,¹ but it is a bit earlier (Jan. – March) in the Reserve.

The ovary develops into a long, slim, beaked seedpod a (silique), less than 1 3/4 inches (4.5 cm) long, which projects upward and outward from the stem. When mature, it splits lengthwise from the base into two valves that coil upwards from the base, exposing 10-18 small, dull brown seeds.

Classification ^2,11,44,143

Milkmaids are dicot angiosperms in the mustard family (Brassicaceae), a family of major economic importance that has very broad distribution. There are many well-known species and cultivars in the family including common vegetable crops such as cabbage, cauliflower, broccoli, turnips, watercress and radish, and ornamentals such as sweet alyssum and stock; there are also invasive weeds such as black mustard, wild radish, and sea rocket. Interestingly, six of our common vegetables–cabbage, cauliflower, kohlrabi, Brussels sprouts, broccoli, and kale–were all bred from a single species of mustard, Brassica oleracea.¹⁴³

Members of the mustard family are characterized by four petals in a cross shape (from which came the former family name Cruciferae, or cross-bearing); and by six stamens, four long and two short. Mustard seedpods come in a variety of shapes. When mature, they split open from both sides, exposing the seeds on a central membrane. Seedpods occur radially around the flower stalk, “like a spiral staircase for the little people.”¹⁴³

Sixteen species in the mustard family have been reported from the Reserve.⁴⁸ Eight of these are non-native weeds, including black mustard and field mustard (Brassica nigra and B. rapa), wild radish (Raphanus sativus), sea rocket (Cakile maritima) and stock (Matthiola incana). Others include lovely spring natives such as milkmaids and wallflowers (Erysimum capitatum).

The species was previously divided into several varieties on the basis of leaf morphology. These are no longer accepted as valid.

Ecology  

The energy for milkmaid’s early spring growth comes from the energy stored in the fleshy rhizome.²⁴⁷

Human Uses  

There are scattered reports that milkmaid plants are palatable.^23,245 Given the general edibility of other mustard plants,¹⁴³ this is logical, but we were unable to find details of local uses.

Occasionally milkmaids are recommended for use in native plant gardens, primarily in the San Francisco Bay area.²⁴⁶ 

Interesting Facts  

The genus name Cardamine comes from the Greek word, “kardamis” that refers to a kind of cress.²¹ This may explain one of the common names: bittercress.

The ancient spice known as cardamom (today the third most expensive spice in the world) also has “kardamis” as a root in its name.⁴¹ Cardamom, the spice, is unrelated to Cardamine, being in the ginger family, along with turmeric and ginger. The relationship implied by the name between cardamom and modern cress is not clear.