Desert Thorn Apple, Toloache, Datura discolor – Native Plant of the Week

Introduction

Desert Thorn Apple, or commonly called Toloache in Mexico, is the species Datura discolor. The Datura genus are of the Solanaceae or Nightshade family along with tomatoes, potatoes, peppers, and eggplants. It is a beautiful, hearty plant worthy of our respect and admiration, but with extreme caution due to its toxicity.

The Desert Thorn Apple is often seen growing on roadsides as well as in semi-open natural areas in sandy soils and washes (dry creek beds in dry climates or deserts where water flows when it rains) throughout its range. Even when it is in the dry season, the Desert Thorn Apple still often appears lush and green when little else is. It has large, beautiful, delicate-looking white trumpet-shaped flowers whose throat is tinged with varying shades of purple. Its beauty and drought tolerance make it popular as a garden plant in its natural range. However, in some areas, it can be illegal to sell, buy or even grow Datura plants.

Toxicity of the Desert Thorn Apple or Toloache

Don’t let the incredible beauty of the large trumpet flowers of Datura discolor fool you. As with all other Datura species, the entire plant is potentially highly toxic. The flowers, leaves, roots, and especially the seeds all contain a potentially lethal mix of toxic alkaloids including scopolamine and atropine. Datura species have been known to poison people, livestock, and pets. Its effects have at times been fatal. Children, in particular, seem to be susceptible to the atropine alkaloids.

If ingested these alkaloids may cause symptoms ranging from dry skin, dry mouth, dilated pupils, muscle stiffness, and confusion to agitation, paralysis, delirium, amnesia, strong hallucinations, and even death. Most human cases of toxicity are from intentional ingestion of a more common closely related species known as Jimson Weed, Datura stramonium. Teenagers and young adults frequently ingest or smoke the plant for its potentially hallucinogenic effects, but often end up hospitalized, or worse, from its unintended toxic side effects.

Avoiding Toxic Effects

It is, however, easy to avoid poisoning from the Desert Thorn Apple as most poisonings are from intentional ingestion. Simply don’t ingest it. Sometimes however it can get mixed in with plant harvests and contaminate livestock feed. If there is a lot of Datura in your fields simply go and remove the plants at harvest time to prevent contamination. There was even a case of poisoning from a certain type of semi-domesticated honey wasp that caused poisoning from honey, though this method of ingestion appears to be quite rare.

Treatment for Poisonings

Most people are hospitalized due to their agitated state. The primary treatment for poisoning is activated charcoal to reduce the absorption of the toxic alkaloids by the stomach. Hospitals may also administer drugs to calm the patients down and counteract the effects. Pets and livestock are treated with activated charcoal.

Description of Datura discolor

Leaves & Stem

Desert Thorn Apple or Toloache is an annual or short-lived perennial sub-shrub that varies considerably in height. It can be a low-growing somewhat sprawling shrub less than 50 cm tall to an upright one growing up to 1.5 m tall. Its tough stalks are green with purple stripes (striations) on them. The purple striations are often quite conspicuous and help aid in its identification to help distinguish it from other species of Datura. The widely ovate-shaped leaves are 5-18 cm long and 3-16 cm wide. The leaves may or may not be toothed (dentate) or slightly wavy-edged (undulate). The surfaces may or may not be variously hairy (pubescent).

Flowers & Fruits

Datura discolor has very large, upright white funnelform (somewhat trumpet-shaped) flowers with varying shades of purple (see photo at top of page). The purple is usually in the throat of the flower but sometimes also on the edges of the flared face (corolla) of the flower. The 8-15 cm long flower tubes are surrounded by a 6-14 cm long tubular calyx. The corolla of the flower is 4-8 cm wide generally with 5 strong points or acumens (and 5 shorter acumens) that are usually short and vary from acute to acuminate on the very edges of the corolla. The flowers are short-lived, opening at night and typically withering after just one day.

It has a spiny roundish (globose) seed capsule 2.5-4 cm wide, as do most Datura species (see photo at top of page). The capsule has 200 to 300 spines that are each 1.3-2 cm long. The capsule splits or dehisces along 4 sutures releasing numerous black kidney-shaped (reniform) seeds. Its persistent round (rotate) calyx surrounds the base of the seed capsule where it attaches to the stem.

Similar Species Frequently Confused With

Datura discolor could easily be confused with any of the other 8-13 species of Datura. The number of species varies with the source. Some experts only accept 9 species while other sources accept up to 14 separate species. All species tend to be highly variable, growing according to their environmental conditions. This can make identification challenging.

There are some key differences that will help you distinguish Desert Thorn Apple from the others. Here is a list of the other species found in the same range as Datura discolor and their differences in habitat or appearance:

• Datura ceratocaula – native to Mexico but prefers swamps or other wet areas, unlike most other Datura species. The flowers often have a bluish tinge. Also unlike all other Datura species, the seed capsules are never spiny making them easy to distinguish.
• Datura ferox – the long spine thorn apple once thought to be native to China actually originated in the Americas and is native to Mexico and Central America. It is known for its particularly long spines on its seed capsules. The leaves are toothed and hairy and its hairy stalks are thick and often tinged with red. It is an upright annual no more than 90 cm tall.
• Datura innoxia – the downy or recurved thorn apple also grows in a similar range, but it is known for its downy soft leaves and stems making the plant appear soft and greyish in color. The flowers are similar in size but usually have recurved edges that bend downwards. The fruits are larger and usually egg-shaped and split irregularly instead of along 4 sutures.
• Datura leichhardtii – grows in similar habitats and to similar heights as Datura discolor. However, this plant is covered with small hairs and has smaller inconspicuous yellowish-white flowers that set it apart from other Datura species.
• Datura quercifolia – found in similar habitats but also survives in moist environments in full sun. It is distinguished by its oak-shaped leaves and its small pale violet funnel-shaped flowers that seldom exceed 4.5 cm long.
• Datura stramonium – common jimsonweed is an aggressive weed throughout the range of Datura discolor. Its flowers however are more fragrant than the Desert Thorn Apple, are only 6 – 9 cm long, generally do not ever fully open, and they are usually white or cream and rarely violet in color. The seed capsules also open along 4 sutures but they are larger, up to 8 cm long, and are oval or egg-shaped, not round.
• Datura wrightii – grows in the southwestern USA and northern Mexico but it is a herbaceous perennial growing to 1.5 m tall and wide. Its leaves are more rounded, tapering to a point and may be wavy but generally are not toothed. The flowers are also large and white (to 20 cm long) and may be tinged with purple, but are much more fragrant and generally last much longer. The similar-sized capsules have more spines (300-400) but they contain tan instead of black seeds.

Habitat & Growing Conditions of Desert Thorn Apple

Desert Thorn Apple, Datura discolor, is common in sunny, dry places throughout the Sonoran desert and surrounding areas of the southwestern USA, Mexico, and Caribbean islands in arid and semi-arid areas. Desert Thorn Apple is also frequently found on roadsides and next to buildings where the eaves protect its delicate flowers from the rains. It is generally only found at lower elevations, below 600 m.

It prefers open sunny areas in sandy soils and washes (dry creek beds) throughout its range. It can be found in part shade but not full shade. It prefers dry soil and can tolerate drought conditions. It can tolerate moist soil types but will not grow in wet soil.

Growing Desert Thorn Apple in Your Garden

If you live in the southwest of USA, Caribbean, Mexico or other nearby areas Desert Thorn Apple will be very easy to grow in your garden. Please check your are to make sure it is legal to grow however as in some states it is regulated. If you are able to grow it then fantastic, native species, once established, require little to no maintenance making them the perfect garden plant.

If given a little TLC Desert Thorn Apple will behave as a short-lived perennial, otherwise it grows as an annual. Collect the seeds each year and scatter them in your chosen spot to grow on their own, or if you prefer you could start them in pots and transfer them to your garden from there. It would be best to start them in newspaper pots, peat pots, or other biodegradable pots so that you do not have to disturb their roots when you plant them in your garden.

Find a nice sunny spot with sandy soil, but amend it with a small amount of organic compost in order to feed it so that it grows larger and produces more flowers than it would in sandy soils alone.

If your soil is too heavy or rich dig out a 50 cm x 50 cm x 50 cm pit and mix sand and/or gravel into the soil before putting it back in the pit. If the area is prone to collect moisture then try planting the seeds on top of a slight mound so that it is higher than the surrounding soil allowing it some extra drainage. When it comes to Desert Thorn Apple the soil really never can be too dry providing you water it if it does happen to look wilted.

Distribution of Datura discolor

In the USA, Desert Thorn Apple is native in California and Arizona. In North America it does not grow any further north than California and Arizona, being entirely absent from Canada.

In Mexico, it is more widespread throughout the western, central, and southern states. It is native in Sonora, Sinaloa, Nayarit, Baja California, Baja California Sur, Mexican Pacific Islands, Jalisco, Guanajuato, Colima, Michoacan, Queretaro, San Luis Potosi, Nuevo Leon, Tamaulipas, Puebla, Guerrero, Veracruz, Oaxaca, and Chiapas. It has also been found in the Caribbean, particularly in Cuba and Puerto Rico, where it is also believed to be native.

Many Datura species have now been introduced around the world. Datura discolor has been introduced to western India and different parts of northern and southern Africa.

Status of Datura discolor

Desert Thorn Apple, Toloache, or Datura discolor, is considered Globally Secure (G5). In the USA, as is the case with most native plants it seems, it is yet unranked. No other information on its status could be found. However, it is a hearty plant that is relatively common in its natural range. It has also been introduced outside of its natural range, so its actual global status is likely fairly Secure.

Traditional or Other Uses of Desert Thorn Apple

In North America Datura species were frequently used ritualistically by shamans, medicine men, and other spiritual leaders to induce hallucinations. Various species were widely used, however, not just the Desert Thorn Apple, but all Daturas in their range. It was reportedly used this way by the Pima, Navajo, Havasupai, and Southern Paiute. The Aztecs of Mexico widely used it by their medicine men, necromancers, and also in their ritualistic sacrifices. It is apparently even an ingredient of the well-known Haitian ‘Zombie Poison”.

Datura discolor the Desert Thorn Apple or Toloache was also used medicinally. Specifically the Pima peoples in North America used it as an analgesic for childbirth, on the skin for sores or to draw pus from boils, as a wash for sore eyes, as a gastrointestinal aid for ulcers, and the heated flowers as a poultice for earaches.

In the Old World, after it was introduced from the New World, it was also used both medicinally and ritualistically. Medicinally it was used in similar ways as Belladonna. Sometimes Datura was also used to poison people, in witchcraft, or as an aid to suicide.

Ethical Wildcrafting of Datura discolor

Ingestion of Desert Thorn Apple, in any form and quantity, is no longer recommended or commonly practiced. If you are however using it in a ritual and not planning to ingest it in any form then please follow standard Ethical Wildcrafting principles. Find a nice large and healthy population to harvest whichever parts of the plant you wish to harvest. Please try not to kill the entire plant when you wildcraft as it is a native species in North America. If you are wanting to grow it in your garden simply harvest the ripe seeds and plant them the following spring.

And of course, be absolutely certain that you bring a paper bag with a pen to carefully label the species and location. Once labeled add “TOXIC IF INGESTED” in large bold print on the bag so that it is never accidentally ingested. While drying keep the label with the plant parts that are drying. Once dried and ready to be stored follow the practice of carefully labeling species and severe toxicity if ingested, again to prevent anyone from accidentally ingesting it and poisoning themselves.

References and Resources

Canadensys Plant Search https://data.canadensys.net/vascan/search

Dictionary of Botanical Terms – by Lyrae’s Nature Blog https://lyraenatureblog.com/blog/dictionary-of-botanical-terms/

iNaturalist Plant Search https://www.inaturalist.org/home

Native American Ethnobotany http://naeb.brit.org/

Natureserve Explorer https://explorer.natureserve.org/

Rel de Herbarios del Noroeste de Mexico https://herbanwmex.net/portal/

USDA Plants Database https://plants.sc.egov.usda.gov/home

Wikipedia on effects of ingestion and treatment: https://en.wikipedia.org/wiki/Datura

Willis, Lyrae (2022).  Plant Families of North America.  Not yet published. 

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