Poison Gardens – Purple Nightshade

A couple of years have passed since we last visited the poison garden (California Buckeye, Poison Oak, and Stinging Nettle). Halloween seems the perfect time for another foray! Many plants in the San Francisco Bay Area have some level of toxicity, enabling them to fend off predators.

Purple nightshade (Solanum xanti) is a perennial, flowering, evergreen shrub that is native to the Western United States, including California. It grows to 35 inches high, with a hairy stem; leaves that are lance shaped to oval, somewhat lobed, and 2 - 3 inches long; a distinctive umbel-shaped inflorescence with purple-blue flowers up to an inch and half wide; and a green berry fruit that is ½ - ¾ inches wide. Nightshade can thrive in a variety of environments, including chaparral, conifer forests, and oak woodlands.

Purple Nightshade (Solanum xanti) - photo by Dawn Endico,
taken on Mitchell Canyon trail, Mt. Diablo, Northern California. (Jepson)

 

Nightshade is toxic, as are other members in the Solanaceace family. All parts of the plant are poisonous, especially the unripe fruit. Toxicity is from Solanine and glycol-alkaloids, chaconine, and solasodine. There is no antidote for Solanum poisoning. Symptoms include:

• Cardiovascular system (tachycardia, arrhythmia, and hypotension)
• Central nervous system (delirium, psychomotor, agitation, paralysis, coma, and convulsion)
• Gastrointestinal track (nausea, vomiting, diarrhea)

The plant is desirable in the landscape, as it is drought-tolerant, tolerates clay soil, grows under native oak, is deer resistant, and commonly blooms from January to May. Since the plant is poisonous, it may not be an appropriate choice for small children or pets.