Chorispora tenella (Pall.) DC.

Blue Mustard

© DETenaglia

Family - Brassicaceae

Stems - Herbaceous, from large taproot, multiple from base and branching above, glandular pubescent (glands slightly yellow-orange) to +40cm tall.

Leaves - Alternate, petiolate, to +10cm long, +4cm broad, lanceolate to narrowly ovate, glandular pubescent, shallowly lobed (toothed) - (mostly on lower portion) or sinuate, the lobes sometimes mucronate.

© DETenaglia

Inflorescence - Loose racemes terminating branches, to +25cm long, glandular pubescent.

Flowers - Petals 4, rose-pink, clawed (the clawed portion to 7mm long) spreading after calyx tube, showy portion of petals 6-7mm long, 2mm wide, ligulate. Stamens 6, anthers yellow, filaments to 5mm long. Ovary terete, 6mm long, .7mm in diameter, glabrous. Sepals 4, erect and forming false "tube" around claw of petals, purple, to 6mm long, 1.2mm broad, linear, glandular pubescent.

© DETenaglia

© DETenaglia

Fruits - Terete, beaked, on short thick stalks to 5mm long, spreading at right angles to stem and then upcurving toward apex of stems, glandular pubescent, to +4cm long total - including beak to +1.5cm long, many seeded.

© DETenaglia

Flowering - April - June.

Habitat - Railroads.

Origin - Native to Asia.

Other info. - Yet another introduced member of the Brassicaceae. The plant is not yet very abundant but there is no doubt it will become well established in the next few years. The pubescence of the stem is very conspicuous and easy to see even without a microscope.

Photographs taken off Highway 9, Platte County, MO., 4-15-00.