This Mexican morning glory was photographed along a busy roadside in México, just outside of the city of San Miguel de Allende. My travel companion for the October morning, David Tarrant (also a frequent BPotD contributor), made sure to stop here to let me get a few photographs before we continued on to see the flowers in the countryside.
Mexican morning glory is native to the tropical New World, but has naturalized in suitable habitats elsewhere. In México, the species is known as quiebraplatos, translating to “cracked plates”. Ipomoea tricolor is often grown as as annual plant in cold-temperate climates. It does not tolerate frost; where freezing temperatures are rare, it will persist as a perennial. Under ideal conditions, it may scramble to as high as 4m (13 ft.).
Hallucinations are the predominant effect after ingesting morning glory seeds. Ingesting 200-300 seeds produces an effect equivalent to 300 micro g of LSD. Vivid visual and tactile hallucinations, as well as increased awareness of colors have been described. Symptoms include facial flushing, nausea, mydriasis, diarrhea, and hypotension (Spoerke and Smolinske 1990). Ipomoea tricolor has a long history of use as a human hallucinogen in southern Mexico, where the seeds were used in the preparation of a drink (Fuller and McClintock 1986). A single undocumented case of poisoning of a pet cat (after ingestion of seeds) has come to our attention. The cat showed erratic behavior and “looked like a lunatic”. There was no apparent permanent damage afterwards. Several cultivars of Ipomoea tricolor are available in Canadian garden catalogs for home gardeners and, with few exceptions, no mention is made of any potential toxic affects [sic] from ingesting the seeds of these plants. Sample cultivars are ”Heavenly Blue”, ”Pearly Gates”, and ”Scarlet O”Hara”. The total alkaloid content is shown to vary, depending on the cultivar grown. It is advisable to remove and destroy the fruiting parts as they develop to avoid ingestion by children or pets.
I feel obliged to add that commercial seeds for ornamental plantings are (apparently) often treated with fungicides or compounds like methylmercury (a cumulative neurotoxin).