Yellow Jessamine, carolina jessamine, Cow Itch, Evening Trumpet Flower
Gelsemium sempervirens is most commonly referred to as Carolina Jessamine or Yellow Jessamine (Crellin and Philpott, 1990; Coffey, 1994) but some other popular names include Cow Itch (Coffey, 1994; Midgley, 1999), Evening Trumpet Flower (Coffey, 1994; Crellin and Philpott, 1990; van Wyk and Wink, 2004), Wild-woodbine, Jasmine (Coffey, 1994), and False Jasmine (van Wyk and Wink, 2004).
G. sempervirens has two related two related species in the same genus of note. The first is G. rankinii. This species is found in the southeastern United States, but is far less common than G. sempervirens. G. rankinii also prefers wetter habitats and has more commercial value (Midgley, 1999). Another closely related species is G. elegans. This species is non-native to the U.S., and it is typically found in India and Malaysia (van Wyk and Wink, 2004).
Geographic Distribution and Habitat
G. sempervirens is a native species to the North America, having been thought to originate in the Southeast (van Wyk and Wink, 2004) and is widely distributed throughout each state in the southeastern U.S. (USDA). The plant frequently grows in woods, on roadsides, and in dense thickets (Midgley, 1999).
The growth habit of G. sempervirens is a vine that grows anywhere from one to twenty feet in height. Vines normally will twine around in a left to right fashion around a tree or other vertical object to reach full sun. Leaves are evergreen, and they measure approximately two inches in length. The leaves are pointed and tend to have short petiole structures. Anchoring and supporting the vine underground are thin and rope-like roots. Each flower has five round-lobed golden letter petals. The petals form in a structure called a corolla tube which resembles a trumpet. Each flower measures approximately 1.5 inches in length, and sexually, each flower is perfect. There are five stamens and one style, which is subdivided into four joined stigmas (Midgley, 1999).
Portion of the Plant Used
Ethnobotanically, only the rhizomes and roots, particularly the fresh rhizomes, are used. Notably, ingestion of other plant structures may be fatal (van Wyk and Wink, 2004).
The first documented medicinal use of G. sempervirens appears to be in the early 1800s on the plantation of a wealthy Southern U.S. planter. The plant was accidentally collected by a slave to treat a fever in the plantation owner, and when the planter ingested the plant, extreme physiological side effects were observed (Coffey, 1994; Crellin and Philpott, 1990). By the late 1880s, physicians all over the U.S. had begun to describe the plant’s uses in treating patients, and the plant had even appeared in popular medical botany textbooks (Crellin and Philpott, 1990). Today, when used correctly, the plant is known to be a powerful analgesic, anticoagulant, antispasmodic, and extremely powerful sedative. When used incorrectly or through simple misidentification, the plant can be extremely toxic and even fatal.
In Indomalaysia, the related species G. elegans has been used traditionally as a plant toxin for murder and/or suicides (Van Wyk and Wink, 2004). Activities of yellow jessamine have also been listed as “analgesic, anticholinesterase, antipyretic, antispasmodic, bronchodilator, CNS (central nervous system) depressant, diaphoretic, hypotensive, mydriatic, nervine, poison, respirasedative, sedative, tonic, and vasodilator” (Duke et al., 2002).
G. sempervirens appears to have a number of psychoactive properties. Gelsemine, an alkaloid extracted from G. sempervirens is reported to be a very effective against chronic pain by acting through spinal a3 glycine receptors (Zhang et al., 2013). There is also the potential to explore G. sempervirens as a new treatment for anxiety as an alternative to the traditional benzodiazepine (brand name drugs such as Xanax, Ativan, Klonopin), which may have side effects (Dutt et al., 2010). Extracts of G. sempervirens have been shown to decrease anxiety in mice, even at high dilutions (Magnani et al., 2010; Dutt et al.,2010; Venard et al., 2011). However, reservations about these experiments have been raised (Chirumbolo, 2011), which are countered in Bellavite et al. (2011).
A specific alkaloid of this species, scopoletin, has been shown to have anti-cancer properties (Bhattacharyya et al., 2008; Khuda-Bukhsh et al., 2011).
G. sempervirens is also very poisonous (Chirumbolo, 2011). Reports have indicated that a child ingesting amounts varying from a single flower to less than 1.2 grams can be a lethal dose. Toxicity occurs by causing severe respiratory depression and then respiratory failure (van Wyk and Wink, 2004).
Side Effects, Interactions, and Contraindications
Contact dermatitis is a common side effect from working with this plant, so care should be taken so as to avoid contact with sensitive skin (Midgley, 1999). Medicinally, this plant is absolutely contraindicated and may interact negatively with patients with heart disease or any unspecified “cardiac weakness.” Side effects include “coma, cyanosis, trouble swallowing, dizziness, double vision, shortness of breath, headache, speech difficulty, muscle stiffness or paralysis, nausea and vomiting, and dry mouth” (Duke et al., 2002).