Wild Mustard, Sinapis arvensis
Family: Brassicaceae; Mustard Family
Vegetative Characteristics:
Seedling: cotyledons rounded to cordate; true leaves alternate, pubescent
Stems: erect, 0.4-0.8 m tall, usually branched at tip, sparsely pubescent
Leaves: alternate, 3.0-25.0 cm long, 1.5-7.0 cm wide, obovate, lanceolate, lyrate-pinnatifid or undivided; lower leaves lobed, margins coarsely toothed; upper leaves oblong to ovate, progressively smaller apically, sessile, clasping; petiole 1.0-7.0 cm or lacking apically, hispid
Reproductive Characteristics:
Inflorescences: ascending or suberect stout pedicels; sepals 4.5-7.0 mm long, 1.0-1.8 mm wide, yellow or green, narrowly oblong, spreading or reflexed; petals 4, 0.8-1.7 cm long, 3.0-7.5 mm wide, bright or pale yellow, obovate; filaments 3.0-6.0 mm long; anthers 1.2-1.5 mm long, oblong
Fruits: silique, 2.5-4.5 cm long, slender ascending, almost upright; beak at tip, flattened, quadrangular
Seeds: oblong, 1.5 mm wide, smooth, blackish blue to dark brown
Special Identifying Characteristics:
⇒ erect, stout winter or summer annual; flowers in conspicuous clusters at ends of branches, yellow; fruit beaked, cylindrical on long stalk
