A woman who fell sick after drinking poisonous herbal tea from a store in San Francisco's Chinatown has died.

Two San Francisco residents — a man in his 50s last month and a woman in her 30s this month — fell critically ill and were hospitalized after consuming herbal tea from the same Chinatown herbalist in San Francisco.

Yu-Ping Xie, a 56-year-old San Francisco resident, died Saturday at a hospital where she had been since February after drinking the tea, Bay City News reported.

"Each quickly developed weakness, and then life-threatening abnormal heart rhythms, requiring resuscitation and intensive hospital care," San Francisco Department of Public Health officials said.

The man recovered and was released from the hospital on March 12. The woman remained critically ill and died in the hospital on March 18.

The tea leaves bought at Sun Wing Wo Trading Company, at 1105 Grant Avenue, contained the plant-based toxin Aconite, a lethal poison, the San Francisco Department of Public Health said.

“Both patients developed symptoms about an hour after consuming the tea,” said Dr. Tomas Aragon, health officer for the city and county of San Francisco.

The two patients each purchased different blends of medicinal teas that were put together for them at the shop. The teas had several ingredients, and the ingredients that were common to both tea mixtures are currently being tested.

"The tea leaves were provided in a plastic bag," which was not labeled, according to Aragon.

Aconite, also known as monkshood, helmet flower and wolfsbane, is used in Asian herbal medicines. But it must be processed properly to be safe.

"This Aconite poisoning, which can come from Chinese herbal teas if not processed correctly, it can affect the heart. It can give them neurological symptoms like tingling; it can also give you nausea and vomiting," Aragon said.

Health officials are working to find the original source of the tea leaves, and they are warning others to stop consuming it. For now, all the tea's ingredients have been removed from the store's shelves.

"Anyone who has purchased tea from this location should not consume it and should throw it away immediately," Aragon said. "Aconite poisoning attacks the heart and can be lethal."

There is no indication that the people were poisoned intentionally, according to officials.

From the San Francisco Health Department:

People who have purchased and consumed the tea, and experienced no symptoms, are safe, but should not consume any more of it. If you consume the tea and experience symptoms, call 911 or go immediately to the nearest hospital.

Symptoms usually begin within a few minutes or up to a couple hours and can depend on the amount ingested. They can include:

Sensory abnormalities:

-- Numbness or tingling of the face, mouth or limbs

-- Weakness in the limbs

-- Paralysis

Cardiovascular abnormalities:

-- Dangerously low blood pressure

-- Palpitations

-- Chest pain

-- Slow or fast heart beat

-- Irregular heartbeats that can lead to sudden death

Gastrointestinal abnormalities

-- Nausea, vomiting

-- Abdominal pain

-- Diarrhea

There is no antidote for Aconite poisoning. Aconite is commonly called monkshood, helmet flower, wolfsbane, “chuanwu,” “caowu,” and “fuzi” and is used in Asian herbal medicine to treat pains, bruises and other conditions. Raw Aconite roots, leaves and flowers are generally toxic but are used only after adequate processing.

San Franciscans with questions can contact California Poison Control 1-800-222-1222 or www.calpoison.org.

Bay City News contributed to this report.