Cestrum is a genus of flowering shrubs in the nightshade family (Solanaceae), subfamily Cestroideae, comprising approximately 150–250 species depending on the taxonomic authority consulted — GBIF records 267 descendant taxa. The genus was described by Carl Linnaeus and is placed in the order Solanales. It was previously treated under the names Habrothamnus and Parqui, among others.
Plants are mostly evergreen shrubs, occasionally deciduous, typically reaching 1.8–3.0 m (6–10 ft) in height. The flowers are small and tubular with five lobes, borne in clusters, and come in a wide range of colors including white, yellow, orange, red, violet, green, and cream. Fragrance varies considerably among species: some bloom and release scent during the day, others only after dark. The fruits are dark berries that give rise to common names such as "inkberry" in English and "Tintillo" in Spanish-speaking regions of South America.
Cestrum is native to warm temperate and tropical regions of the Americas, from the southernmost United States (Florida and Texas) southward through Central America and the Caribbean to central Chile. Several species have been introduced beyond this native range into Asia, Africa, Europe, and other parts of North America, where some have become invasive. All parts of the plant are toxic if ingested; the berries are particularly dangerous and can cause severe gastroenteritis, hallucinations, vomiting, and in serious cases liver failure or paralysis.
In cultivation, cestrums are popular ornamental shrubs prized for their prolific flowering and often powerful fragrance. They thrive in USDA hardiness zones 9–11 and can be grown as container plants in cooler climates, overwintered indoors. They attract bees, butterflies, and hummingbirds, and the foliage serves as a food source for caterpillars of several Lepidoptera, including glasswing butterflies.
Etymology
The name "Cestrum" was applied by Linnaeus when he formally described the genus in 1753. In everyday use, members of the genus are called "cestrums" or "jessamines" — the latter term is borrowed from "jasmine" and reflects the strongly scented flowers characteristic of many species, though cestrums are not true jasmines and belong to an entirely different family. In Spanish-speaking parts of South America, species are known as "Tinto" or "Tintillo," words meaning a dark or tinted liquid, almost certainly a reference to the dark, ink-like berries. The Afrikaans name "Sestrum-inkbessies" similarly combines the genus name with a direct reference to the inkberry fruits.
Distribution
Cestrum is native to the warm temperate and tropical Americas. Its natural range extends from the southernmost United States — specifically Florida and Texas — southward through Mexico, Central America, and the Caribbean island chains, continuing down the length of South America to the Bío-Bío Region of central Chile. This broad latitudinal span reflects the genus's tolerance for a range of tropical to subtropical and warm temperate climates.
Beyond its native range, multiple Cestrum species have been introduced to Asia, Africa, Europe, and further parts of North America, typically as ornamental plants. Some of these introductions have resulted in naturalized or invasive populations, most notably in Australia.
Ecology
Cestrum species occupy a variety of warm, often humid habitats within their native range, typically growing as understory or edge shrubs in tropical and subtropical forests. The tubular flowers of different species are adapted to different pollinators: day-blooming species such as C. diurnum attract insects active during daylight, while night-blooming species such as C. nocturnum release their fragrance after dark, targeting nocturnal pollinators including moths. The dark berry fruits are likely dispersed by birds.
The foliage supports caterpillars of several Lepidoptera species, including glasswing butterflies (Ithomiini), making cestrums a notable larval host plant in Neotropical ecosystems.
All parts of Cestrum plants contain toxic compounds. Ingestion can cause severe gastroenteritis in humans, with symptoms including headaches, hallucinations, vomiting, paralysis, and potential liver failure. The plants are also piscicidal — toxic to fish. Of particular concern in pastoral settings is C. parqui (green cestrum), which causes documented livestock losses in Australia when animals consume dried leaves that retain their toxicity.
Cultivation
Cestrum species are valued ornamentals in warm-climate gardens, grown for their prolific, often intensely fragrant flowers and their ability to attract pollinators. They are suited to USDA hardiness zones 9–11 and perform best with full sun to partial shade — afternoon shade is beneficial in hot climates. Plants prefer moist, well-drained, loamy soil across a wide pH range from acid to alkaline.
In cultivation, plants typically reach 3–13 feet (roughly 1–4 m) in height and spread, depending on species. Flowering occurs primarily in summer, with some species blooming over an extended season. Common landscape uses include borders, informal hedges, screens, containers, and specimen planting. Cestrum 'Newellii,' a red-flowered cultivar, has been awarded the Royal Horticultural Society's Award of Garden Merit (confirmed 2017), attesting to its ornamental reliability.
Propagation
Cestrum is most commonly propagated from stem cuttings taken in late summer. This method reliably reproduces the characteristics of the parent plant and is the standard approach for ornamental cultivars.
Conservation
No Cestrum species are globally assessed as threatened on the IUCN Red List based on available sources. The primary conservation concern associated with this genus runs in the opposite direction: several species, most prominently C. parqui (green cestrum), have become invasive outside their native Americas range. In Australia, green cestrum is established as a weed of significant concern, causing documented livestock deaths when animals graze dried leaves. Its spread in Australian ecosystems has prompted inclusion on regional weed management programs.
Cultural Uses
In Brazil, the indigenous Krahô people use C. laevigatum in shamanic practice. The plant is considered a potent entheogen, employed by shamans "to see far" and as an aid to divination. It is not used recreationally; access is restricted to initiated practitioners. This use reflects a broader pattern of Solanaceae species being employed across Mesoamerican and South American cultures for their psychoactive properties.
Taxonomy
Cestrum L. was formally described by Carl Linnaeus in 1753, placing it in the family Solanaceae. The genus has accumulated several synonyms through the history of botanical nomenclature, including Habrothamnus Endl. (1839), Parqui Adans. (1763), Meyenia Schltdl. (1833), Fregirardia Dunal ex Delile, and Lomeria Raf. (1838). Of these, Habrothamnus and Parqui are the most frequently encountered in older horticultural literature. The genus is placed within subfamily Cestroideae, tribe Cestreae. Species counts vary among authorities: Wikipedia gives 150–250 species, NCSU cites approximately 232 accepted species, and GBIF records 267 descendant taxa across all taxonomic ranks.
