Brassica napus L.
Family - Brassicaceae
Stems - To +80cm tall, bluish-green, glabrous, glaucous, herbaceous, erect, branching above, typically single from base, from taproot.
Leaves - Alternate, sessile, glabrous, glaucous. Basal leaves lyrate-pinnatifid, dentate, to +15cm long. Auricles rounded. Cauline leaves sessile, clasping, auriculate, reduced above, to 9cm long, 3cm broad. Auricles rounded and broad.
Inflorescence - Terminal racemes, compact in flower and elongating in fruit to +30cm. Pedicels 6-10cm long in flower, elongating in fruit to +3cm and eventually at or near perpendicular to the axis of the inflorescence, glabrous, glaucous.
Flowers - Petals 4, yellow, clawed, glabrous. Claw to 5mm long, pale yellow to whitish. Limb to 5mm long, 4mm broad, rounded to blunt at apex. Stamens 6, 4 larger and 2 smaller (the two smaller stamens opposite and outside of the larger stamens). Filaments to 7mm long, glabrous, yellow-green. Anthers yellow, 2mm long. Ovary glabrous, green, terete, 4-5mm long. Style 1.7mm long, persistent in fruit. Stigma capitate. Sepals 4, 6-7mm long, to 2mm broad, linear, glabrous, yellow-green, erect to spreading, often with revolute margins. Siliques to +6cm long, terete, ascending and almost parallel with the axis of inflorescence, beaked, glabrous. Beak to 9mm long.
Flowering - April - September.
Habitat - Roadsides, railroads.
Origin - Native to Eurasia.
Other info. - This is the
species plant which gives rise to the Rutabaga. Chromosome numbers show
that, originally, the plant was a hybrid between B. campestris
L. (Turnip) and B. oleracea L. (Cabbage, Broccoli,
Photographs taken off Highway 9, Platte County, MO., 5-2-00.