FAMILY: Cruciferae (Brassicaceae)—the Mustard Family
This is a large assemblage of pungent or acrid herbs of diverse growth habit. Flowers: regular and perfect, in terminal racemes or corymbs; sepals: 4, deciduous; petals: 4, limbs spreading to form a cross; stamens: 6, with 2 shorter and inserted lower than the other 4; pistil: 2 carpels; ovary: superior; fruit: a 2-celled capsule (a silique when elongated, a silicle when short and broad) usually opening by 2 valves from below; seeds: with a curved embryo important in taxonomic diagnosis; leaves: alternate, herbaceous without stipules.
This family includes many ornamental and important vegetable crops. A nonexhaustive list contains: Brassica (broccoli, Brussels sprouts. cabbage, Chinese cabbage, kale, kohlrabi, mustard, rutabaga, turnip), Lepidium (cress), Nasturtium (watercress), Raphanus (radish), Armoracia (horseradish), Wasabia japonica (Japanese horseradish), and Crambe (oil-seed).
PHENOLOGY: The genus Brassica contains several species that generally flower from May through October, depending on the taxon.
DISTRIBUTION: Some species of Brassica are cultivated plants; others are troublesome weeds of fields, waste places, gardens, and roadsides.
PLANT CHARACTERISTICS: Taxonomically the genus has been organized in several different fashions. Most members encountered in the Commonwealth bear saccate sepals, yellow petals, and have 4 rounded staminal glands at the base of the ovary. The fruit is terminated by a conspicuous beak, sometimes containing a basal seed.
POISONOUS PARTS: Seeds and plants with seed capsules are poisonous.
SYMPTOMS: The effects of Brassica poisoning vary depending upon the species of plant consumed Brassica Kaber(DC) L. (charlock; wild mustard) is known to cause gastroenteritis, pain, salivation, diarrhea, and upper digestive tract disturbances, including irritation of the mouth. These symptoms also are associated with B. hirta Moench. (white mustard) ingestion. Some cultivated mustards such as Brassica oleracea var acephala DC (common kale), B. o. var capitata L. (cabbage), and B. o. var. gemmifera Zenker, (Brussels sprouts), cause hemolytic anemia and hemoglobinuria in some livestock. Goitrogenic substances (LS-vinyl-2-thioaxazolidone) are known in kale, cabbage, and turnip (Brassica rapa L.).
Postmortem: gross lesions: (rape and kale) pulmonary emphysema; congestion and edema of lungs, alimentary tract inactivity causing gallbladder distension with viscid bile; histological lesions: rupture of pulmonary alveoli, emphysema and edema involving interlobular septa tracheal and bronchial hemorrhages, mild toxic hepatitis, and centrilobular necrosis.
POISONOUS PRINCIPLES: The substance responsible for toxicosis is sinigrin, which in the presence of the enzyme myrosinase, is converted to glucose, allyl isothiocyanate (mustard oil), and potassium hydrogen sulfate. Mustard oils are poisonous. The toxicity, by ingestion, of allyl isothiocyanate has been determined (in cattle) to be 0.001% of the body weight. Also, mustards occasionally contain toxic concentrations of nitrate that may complicate toxicosis.
CONFUSED TAXA: There are 40 genera of mustards; many are yellow flowered. Botanical keys for the identification of mustards are complex and require mature fruits. One species frequently mistaken for a Brassica is Barbarea vulgaris R. Br (Yellow rocket, winter cress), which also has been reported to produce mustard-oil type poisoning. One feature used to separate Brassica from Barbarea is the beak of the fruit: 8- 15 mm long in Brassica, 1-3 mm long in Barbarea.
SPECIES OF ANIMALS AFFECTED: Reported poisonings include, cattle and sheep, Brassica hirta (white mustard); cattle and swine, B Kaber (charlock); and ruminants, large quantities of Brassica oleracea var. botrytis (broccoli). Goiter formation is known for lambs (ewes) fed on Brassica oleracea var. acephala (kale) and rabbits fed Brassica oleracea var, capitata (cabbage).
OF INTEREST: Numerous members of the mustard family have been reported to cause poisoning Winter cress (Barbarea vulgaris) flowers April through June and is an abundant weed in Pennsylvania. One case was reported of a horse ingesting a relatively large amount of B. Vu/garis and developing gastroenteritis. Rape (Brassica campestris L ), although a late fall pasturage crop, has been suspected of causing toxicosis. Horseradish (Armoracia rusticana P. Goertn.) has caused bloody vomiting and diarrhea in humans when consumed in large quantities. Loss of cattle, horses, and swine are known from the ingestion of vegetation and roots. Small children, who eat large quantities of raw mustard vegetables (cabbage, mustard, kale, Brussel sprouts, cauliflower, broccoli, rutabaga, turnip, radish, cress, horseradish and stock) can develop diarrhea and vomiting. Field penny-cress (Thlaspi arvense L.), a common weed of fields, roadsides, and waste places, is responsible for gastric distress in livestock. It has been suggested that toxicity in members of the mustard family increases after flowering. Additional plants suspected of being poisonous are Erysimum (wallflower), Sisymbrium (Tumbling mustard), Descurainia (Herb-Sophia), Camelina (False flax) and Bepidium (Peppergrass).