The term “Indian Hemp” is an ambiguous common name that has been applied to multiple, botanically distinct species. Historically, the name has been associated with certain fibrous varieties of the plant genus Cannabis, but it also widely refers to a completely unrelated North American perennial. The common name, therefore, does not denote a single plant, but rather two very different species with contrasting chemical compositions and effects on the human body.
Clarifying the Confusion: Indian Hemp vs. Cannabis
The confusion surrounding “Indian Hemp” stems from the historical application of the name to both Cannabis indica and the North American native plant Apocynum cannabinum. While the term “Indian Hemp” was once used to describe a powerful variety of the Cannabis plant, the modern botanical reference is primarily to Apocynum cannabinum. These two species belong to entirely different plant families and possess fundamentally different properties, which is a crucial distinction for public safety.
Cannabis belongs to the Cannabaceae family and is known for producing cannabinoids, such as THC. Conversely, Apocynum cannabinum is a member of the Dogbane family (Apocynaceae), which produces no psychoactive compounds. The latter plant’s specific epithet, cannabinum, was given only because its strong, fibrous stems were historically used similarly to true hemp for cordage.
Characteristics of the Plant: Apocynum cannabinum
Apocynum cannabinum, commonly known as Hemp Dogbane, is a bushy herbaceous perennial native to a large area of North America, including the southern half of Canada and most of the United States. It often grows to a height between two and four feet and is typically found in disturbed areas, along roadsides, and in open woods or prairies. The plant is characterized by its smooth, upright stems, which are often reddish in color and contain a milky, sticky sap.
The leaves of this plant are arranged oppositely along the stem and are typically ovate to elliptical in shape. Small, greenish-white, bell-shaped flowers appear in clusters at the tips of the branches from May to July. These flowers develop into distinctive fruits, which are slender, paired, and drooping pods. These pods, called follicles, contain numerous small seeds attached to a tuft of white, silky hairs that aid in wind dispersal.
Historical and Traditional Applications
The common name “Indian Hemp” is a direct reference to the plant’s extensive use by indigenous peoples across North America. Historically, the primary value of Apocynum cannabinum lay in the strong bast fibers found within its stems, which were a highly prized material for textiles and cordage. These fibers were extracted by processing the stems, often harvested in the fall, and then woven into strong thread, rope, and nets.
This durable fiber was used to create essential items, including clothing, bags, fishing lines, and snares. Beyond its utility as a fiber source, the plant was recognized in traditional herbal medicine for its potent properties. Preparations from the roots were historically used as a diuretic to treat fluid retention, or edema. Traditional practitioners also utilized it as a cardiotonic agent, indicating its effect on the heart, and as a diaphoretic to induce sweating.
Safety and Toxicity Concerns
Apocynum cannabinum is a highly toxic plant due to its chemical composition. All parts of the plant, including the stems, leaves, and flowers, contain potent compounds known as cardiac glycosides. The presence of these compounds means that ingestion can directly affect heart function.
The cardenolides in the plant can cause fatal cardiac arrhythmias and are toxic to humans, dogs, cats, and livestock. Symptoms of poisoning include gastrointestinal irritation, nausea, vomiting, weakness, diarrhea, and, in severe cases, cardiac arrest. Because the toxic dose can be quite small—as little as 15 to 30 grams of green leaves can be lethal to a cow or horse—the plant should never be consumed or used for self-medication.