Ketsanee and I often get the question by a visitor whether or not a certain plant is a jasmine. Since none of us are English we have to admit we do not know; the question is of linguistic character rather than botanical. The English word ‘jasmine’ seems to be applied to any white or yellow fragrant flower, no matter its family affinity (orange family, gardenia family, plumeria family or olive family). If we switch from the undefined vernacular names to precise scientific names then we can answer questions.
Depending on author and species concept the genus Jasminum (Oleaceae) encompass some 200-450 species in Africa and Asia. In addition there are many garden cultivars. The genus lacks the white latex of the Tabernaemontana and other plumeria relatives (Apocynaceae), its fruits lack the glandular peel of orange jessamine (Murraya paniculata, Rutaceae) and the petals of Jasminum are free, not fused as in the gardenia/coffee family (Rubiaceae).
The scientific or international genus name ‘Jasminum‘ was coined by Linnaeus in Species Plantarum (vol. 1 page 7) from 1753. He used Jasminum officinale (syn. J. grandiflorum) as the type for the genus, ‘Habitat in India’. He grew it in his own garden Hortus Upsaliensis and he also saw it in the Netherlands in Hortus Cliffortianus. That original Jasminum species and its French name ‘jasmine’ was already widely known in Europe in the 18th century. It had been introduced by Moors to Spain, originally native to Pakistan and India but widespread in Arab countries and probably conspecific with J. grandiflorum which grows in Southwestern China. Vernacular English names are Catalonian or Spanish Jasmine. In Arabic and Persian the plant is known as ‘yasamin’, a common girl’s name even today.
The epithet ‘officinale’ means it was a medicinal plant. Jasmine oil is used for skin ointments, scent-making and perfuming tea. Jasmine rice (‘kao hom mali’ in Central Thai) has a natural scent of jasmine (‘mali’ or ‘malee’ is translated ‘jasmine’ and is a common girl’s name in Thailand).
According to Peter Shaw Green (2000) who wrote the chapter on the olive family (Oleaceae) in Flora of Thailand (vol 7:271-340) there are eight genera and 63 species in Thailand. Within this family there are 31 species of Jasminum in Thailand, including four introduced garden species which have been cultivated here for centuries: J. grandiflorum, J. auriculatum, J. multiflorum and J. sambac.
Determining whether or not a plant is a Jasminum is easy. Identifying which species of Jasminum is really tricky! These two species grow at Dokmai Garden. They were bought at the Khamtieng flower market north of town. Vendors can only provide local names and two vendors of the same plant may not share the same vernacular names. Illustrated garden books usually only show a handful of examples and the books’ scientific names are not always reliable, or the books arrange the plants in Thai alphabetical order after arbitrarily selected vernacular Thai names, meaning the genus Jasminum is scattered all over the book together with unrelated plants with similar vernacular names. The lack of illustrations and the absurdly technical language without pedagogic definitions make me sometimes wonder if a scientific identification key was written to make sure only one person remains the expert. Internet is so crowded with mistakes it can in many cases not be trusted unless an article is written by an authority. Fuzzy indeed!
To the best of my efforts, the species to the left with simple glabrous laurel-shaped leaves, narrow petals and reddish, glabrous and needle-like sepals (calyx lobes) is a garden cultivar of Jasminum laurifolium, variety ‘nitidum’ (syn. J. nitidum). The wild natural Thai varieties have much more narrow leaves and smaller flowers. Using the key of Flora of Thailand you end up with J. adenophyllum, but that key does not include everything you find for sale.
To the right with broader but shorter petals, crowded flowers, leaf-like green hairy bracts, green hairy linear sepals and hairy heart-shaped leaves is Jasminum multiflorum. This species is native to deciduous forests in India, and may be wild or naturalized in Southeast Asia. A picture identical to Dokmai Garden’s Jasminum multiflorum is labeled J. annamense in the beautiful Thai book ‘Fragrant and Aromatic Plants’. However, according to Flora of Thailand J. multiflorum has leaf-like bracts while J. annamense has linear bracts.
Other common garden Jasminum are J. grandiflorum and J. auriculatum, but both have compound leaves and although that is not always evident in J. auriculatum where the two side leaflets are ephemeral, its sepals are tiny. Jasminum sambac is very commonly grown too, but it has green and glabrous sepals.
To avoid that I add to the internet confusion, I urge the Dokmai Dogma readers to comment on these identifications.
Text & Photo: Eric Danell