Chorispora tenella

Usually, members of the Mustard family have small white or yellow flowers with nectar that is accessible to insects with short mouthparts. Blue Mustard is distinctive in that each flower has narrow pink or purplish pink petals, a tubular calyx, and a small throat. Other members of the Mustard family with pink or purple flowers include Hesperis matronalis (Dame's Rocket), Lunaria annua (Money Plant). However, the flowers of Dame's Rocket and the Money Plant are larger (more than ¾" across) and their petals are more rounded. Another species in the Mustard family with similar flowers is Iodanthus pinnatifidus (Purple Rocket). However, this latter species has light blue-violet flowers, glabrous stems, and broader leaves toward the base of the plant that are pinnately lobed or ovate with serrated margins. The siliques of Purple Rocket lack a beak and they are more straight than the siliques of Blue Mustard.

This adventive plant is a winter or early spring annual about ½–2' tall. It is more or less erect and branches occasionally. The round stems are light green and sparsely covered with short glandular hairs. The alternate leaves are greyish or bluish green and up to 2½" long and 2/3" across. They are narrowly ovate or oblanceolate, dentate and slightly undulate along the margins, and sparsely covered with short glandular hairs. The tip of each leaf is blunt or acute; it tapers gradually to a petiole-like base. The upper stems terminate in racemes of flowers up to 1' in length. Only a few flowers bloom at the apex of each raceme, while the siliques (slender seedpods) develop below. The central stalk of each raceme has a tendency to zigzag between the flowers. Each flower is about ½" across and ½" long. It consists of 4 narrow petals that are pink to purplish pink, 4 linear sepals that are purplish pink and slightly hairy, several stamens, and a pistil. The throat of this flower is quite narrow; its calyx is cylindrical, while the petals are widely spreading and form a cross. The blooming period occurs from mid-spring to mid-summer and lasts about 2-3 months. There is no noticeable floral scent. Each flower is replaced is replaced by a stout silique that curves upward and tapers to a beak. The pedicel of each silique (or flower) is quite stout and about 1/3" long. Each silique is about 1–1½" long when fully mature. The seeds have a smooth surface and are slightly flattened. The root system consists of a stout taproot. This plant spreads by reseeding itself.

Blue Mustard is an uncommon plant that occurs primarily in NE Illinois and scattered counties elsewhere (see Distribution Map). It is originally from Asia and can be found as an adventive plant in the drier Western states, where it is more common. In Illinois, local populations usually don't persist. Habitats include areas along railroads and roadsides, stock yards, and nursery grounds. Disturbed areas are preferred.

Chorispora tenella (Pall.) DC.:
Afghanistan (Asia)
Canada (North America)
India (Asia)
Kyrgyzstan (Asia)
Kazakhstan (Asia)
Mongolia (Asia)
Pakistan (Asia)
Russian Federation (Asia)
South Korea (Asia)
Tajikistan (Asia)
United States (North America)
China (Asia)
Turkmenistan (Asia)
Uzbekistan (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Anhui, Gansu, Hebei, Henan, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shandong, Shanxi, Xinjiang [Afghanistan, India, Kashmir, Kazakhstan, Korea, Kyrgyzstan, Mongolia, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; N Africa, SW Asia, Europe].

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Distribution: Most of Europe and Asia; perhaps introduced in N. America.

Annual, 10-25 (-40) cm tall, erect, branched from the base, glabrous or sparsely glandular. Basal leaves rosulate, oblanceolate, sinuate-toothed, 30-80 mm long, 5-20 mm broad, stalked; upper leaves shortly stalked to sessile, similar but becoming smaller upwards. Racemes 10-20-flowered, lax, up to 20 cm long in fruit. Flowers c. 10 mm across, pink or violet, sometimes whitish; pedicels up to 5 mm long in fruit. Sepals 5-6 mm long. Petals 9-11 mm long, c. 2 mm broad. Stamens 5:7 mm long; anthers c. 1.5 mm long. Siliquae 25-30 (-35) mm long, 1.5-2 mm broad, linear-cylindrical, tapering towards the apex, often curved upwards, subtorulose, breaking transversely into several 2-seeded parts; beak-like upper portion c. as long as the body (10-15 mm long), ending in a conical bilobed stigma; seeds c. 1 mm long, suborbicular, brownish.

Herbs annual, (5-)10-40(-56) cm tall, with multicellular glandular trichomes, these sometimes mixed with simple ones. Stems erect, branched above. Basal leaves not rosulate, often withered by flowering; petiole (0.5-)1-2(-4) cm; leaf blade oblanceolate or oblong, (1.5-)2.5-8(-13) × (0.4-)0.8-2(-3) cm, glandular, base cuneate or attenuate, margin sinuate-dentate to dentate, apex acute. Cauline leaves similar to basal ones, progressively reduced in size upward, uppermost often entire and subsessile. Flowers in racemes. Fruiting pedicels stout, (2-)3-5 mm, divaricate, glandular. Sepals purplish, linear, (3-)4-5(-6) × 0.5-0.7 mm. Petals purple, oblanceolate, 8-10(-12) × 1-2 mm, obtuse at apex; claw 6-7 mm. Filaments 4-6(-7) mm; anthers narrowly oblong, ca. 1.5 mm. Fruit linear-cylindric, (1.4-)1.8-2.5(-3) cm × 1.5-2 mm, slightly curved upward, corky, subtorulose, with 8-12 constrictions on each side, glandular or rarely glabrescent; style 1-1.7(-2.1) cm. Seeds brown, oblong, 1-1.4 × 0.8-1 mm. Fl. Apr-Jun, fr. May-Aug. 2n = 14.

Raphanus tenellus Pallas, Reise Russ. Reich. 3: 741. 1776; R. monnetii H. Léveillé.

Blue Mustard is an uncommon plant that occurs primarily in NE Illinois and scattered counties elsewhere (see Distribution Map). It is originally from Asia and can be found as an adventive plant in the drier Western states, where it is more common. In Illinois, local populations usually don't persist. Habitats include areas along railroads and roadsides, stock yards, and nursery grounds. Disturbed areas are preferred.

Pastures, roadsides, fields, waste areas; 100-2200 m.

The nectar of the flower is accessible to long-tongued bees, beeflies, butterflies, skippers, and moths. The mouthparts of other insects are too short. Little is known about this plant's relationships to birds and mammalian herbivores. The foliage is not considered to be toxic; it is possible that the seeds can pass through the digestive tracts of livestock, facilitating the dispersal of this plant to new areas.

Foodplant / spot causer
colony of Pseudocercosporella anamorph of Mycosphaerella capsellae causes spots on live leaf of Chorispora tenella

Fl. Per.: April-June.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 3
Specimens with Barcodes: 3
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

The preference is full sun and mesic to dry conditions. Blue Mustard tolerates different kinds of soil, but it is more commonly found in poor soil that contains clay or gravel because of the reduced competition from other plants.