FAMILY: Rosaceae - the Rose Family
This large family of plants contains many genera and numerous species with leaves: mostly alternate, flowers: bisexual, regular. and 5-merous; stamens: 5 to many, borne on the edge of a calyx tube; pistils: 1 to many; ovary: superior or inferior; fruits: achenes, follicles, berries, pomes, or drupes.
PHENOLOGY: Both species flower in May.
DISTRIBUTION: Both species are found along roadsides, fencerows, waste land, and forest margins.
PLANT CHARACTERISTICS: The two species are similar in appearance. Prunus serotina is a tree to 25 m; leaves: lanceolate to oblong or oblanceolate (ovate in P. virginiana) and 6-12 cm; acuminate at the tip; serrated with incurving, blunt, callous teeth (sharply serrulate in P. virginiana); racemes: 8-15 cm long, terminating current-season leafy twigs; pedicels: 3-6 mm; sepals: 1-1.5 mm long, persistent in P. serotina, deciduous in P. virginiana, flower petals: white and 4 mm long; fruit: dark purple or black (red in P. virginiana); 1 cm thick. The inner bark is aromatic only in P. serotina.
POISONOUS PARTS: Leaves, twigs, bark, and the stone (pit) produce toxicosis.
SYMPTOMS: Poisoning produces anxiety, staggering, falling down, convulsions, dyspnea, rolling of eyes, tongue hanging out of mouth, loss of sensation dilated pupils; the animal then becomes quiet, bloats, and dies within a few hours of ingestion. Postmortem: gross and histological lesions: bright red blood; congestion of internal organs.
POISONOUS PRINCIPLES: Cyanogenic glycosides (prunasin, produced in leaves and twigs, and amygdalin, produced in the pit) release hydrocyanic acid (HCN). Less than 1/4 lb of fresh leaves can be toxic to a 100 lb animal. Conflicting reports suggest wilting may increase HCN release. Wilted leaves are more toxic per unit weight due to loss of water by the leaves, which concentrates the cyanide.
CONFUSED TAXA: The genus Prunus is readily recognized from the description provided. Pokeweed (Phytolacca americana) berries may be confused with those of Prunus (see Phytolacca).
SPECIES OF ANIMAL AFFECTED: Humans and all species of livestock are susceptible to HCN poisoning from the cyanogenic glycosides.
TREATMENT: (11a)(b); (25); (26); immediate injections of sodium thiosulfate and sodium nitrite may alter the minimum lethal dose.
OF INTEREST: Prunus contains many useful plants that also may be poisonous. Peach pits (Prunus persica Batsch.) are rich in cyanide and have been responsible for animal toxicosis. Apricot kernels (Prunus armeniaca L.) have been fatal when consumed by children. Plum pits and bitter almond pits are also cyanogenic. It should be noted that seeds of both the common apple and crabapple (Malus spp ) contain HCN. The death of a man, resulting from eating a cup of apple seeds at once, has been reported.
The poisonous ornamental jetbead bush (Rhodotypos scandens (Thunb.) Mak. = R. tetrapetala Mak.) of horticulture produces a cluster of four, black, shining, berrylike drupes, that are persistent even in winter. The attractive drupes are subtended by 4 spreading, jagged sepals. The shrub grows to 2 m in cultivation. Jetbead has greenish-brown twigs and opposite leaves, glabrous, doubly serrate, to 4 cm long. Symptoms are those for amygdalin poisoning discussed above; treatment; (11a)(b);(25).