The kilua or kiluwa (pl. Vilua/viluwa) is a small fragrant magnolia-like flower found on the East African coast. The flower’s tree is known as mlua, mkiluwa or muuwa by the Swahili and mlua, mrua, mchilua, and chingade by the Digo¹. They are quintessentially East African.

Kilua flowers have six yellow-green tongue-shaped petals with purple highlights at their inner base. The petals alternate between two sizes along the rounded centre, forming a cup shape. The flower hangs upside down on the trees’ branches, hidden by leaves from the eyes and hands of curious women. If you would like to know just how hidden these flowers are, try googling the phrase ‘kilua flower’—all you will find are images of an anime character called Killua Zoldyck posing with roses, daisies, sunflowers, and carnations. 

There is one fool-proof way to find the flowers online: by using their tree’s lesser-known scientific name, Mkilua Fragrans. The terrestrial shrub got its scientific name in 1970 from a British botanist called Bernard Verdcourt. After centuries of use by the people of the Swahili coast, Verdcourt described the species using botanical terms for the Western scientific world. He listed vilua under the family Annonaceae, which is commonly referred to as the custard apple or soursop family. Previously, a botanist named R. O. William placed the plant in the genus Desmos together with ylang-ylang plants and assumed it was native to India. Verdcourt, who found the plant in evergreen forests on the East African coast, could not confirm William’s assertions. He decided to classify the small tree in its own genus, Mkilua².

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Kingdom: Plantae
Clade: Tracheopythes
Clade: Angiosprems
Clade: Magnolids
Order: Magnoliales
Family: Annonaceae
Genus: Mkilua (Verdc.)
Species: M. fragrans

Binomial name: Mkilua Fragrans

The mkilua plant mainly grows as a shrub or a small tree up to 5 metres tall. Its natural habitat is Kenya and Tanzania’s moist coastal forests³. Though its range of growth in terms of altitude is listed as 0-400m above sea level, coastal people who live in high altitude areas, like Nairobi, have managed to grow them in their gardens.

The flowers and their scent are intrinsic to the culture of the East African coast. They have a radiant, sweet and slightly fruity-floral scent that has become part of the Swahili heritage. A ripe kilua hanging on a tree is no secret to passers-by. Their heavy scent punctures the air, delighting those who come across it.

Vilua are important to Swahili seduction and romance and are said to have aphrodisiac qualities. The flowers ripen in the evening before sunset and are picked right away to ensure they remain fresh for one of their main uses, scenting matrimonial rooms. Women plant the trees close to their bedroom windows so that the evening scent can waft into their rooms.

When the yellow gems are not being tucked away in pillows at sunset, they are used to make garlands and floral brooches in conjunction with jasmines, roses, nargis and ylang-ylang. The garlands and brooches, called koja, vikuba and vishada depending on their shape and size, are a significant feature in Swahili weddings. The floral pieces are adorned on newlyweds and key family members during wedding celebrations.

Vilua’s concentrated scent make them ideal for perfuming body oils and body parts. Women put a few of them in bottles of coconut oil to enhance its smell or tuck the petals in their hair. Some men place the flower under their kofia or in their breast pocket, leaving trails of the fragrance wherever they go.

Indigenous gardeners have mastered the art of growing the strongest, sweetest mkilua plants. The tree is difficult to cultivate, is prone to water stress, and it needs continuously watering during the dry season. Fish scales often dot the soil at the base of the mkilua; wastewater leftover from cleaning fish has long been used as a fertiliser. An analysis of fish water showed a high concentration of nitrites/nitrates and some ammonia, which improves the plant’s growth and consequently, the scent of the flower¹. Some also believe that the fish water’s odour keeps away evil spirits that would otherwise be attracted to the flower’s sweet aroma.

In addition to its fragrance, the mkilua plant has several medical uses. Scientific studies highlight that the tree and its flowers contain a fatty acid, mkiluaynoic A, with antifungal properties. Mkiluaynoic A works against Candida albicans, a pathogenic yeast found in the human body which causes fungal infections when there’s too much of it present⁴. The radiant aroma of the kilua serves as a mosquito repellent⁵. Most impressive of all is the claim that it has antidepressant characteristics¹.

The mkilua tree has been listed as vulnerable by the International Union for Conservation of Nature (IUCN) in the Union’s Red List of Threatened Species⁶. The IUCN Red List is based on set criteria which evaluate the risk of extinction of species and subspecies worldwide. The main threats to this species in the wild is habitat degradation due to forest clearance for agriculture and expansion of urban areas and logging for charcoal production⁷. Most of the sites where the species is known to occur are located outside protected areas³ such as national parks and forest reserves.

Chances of spotting a mkilua tree in a Swahili garden are becoming rarer each day. Knowledge of how to grow the tree is slowly fading away as fewer people are planting it with every new generation. Those who still plant and maintain the tree hide them away from prying hands by planting them far from fences and paths with heavy foot traffic, or behind high walls; the precious blooms are shared only amongst their friends and family.

Despite the mkilua plant’s vast potential as a source of essential oil, there is a minimal large-scale commercial use of the tree and its flowers. In a study conducted by Dr. Njaya Muhammad in Lamu, Malindi, Kilifi, Mombasa and Msambweni he found that most people who have domesticated the plant have less than three plants in their home. Large scale growers are mostly located within towns such as Malindi, Mombasa and Stone Town Zanzibar where there is a high demand for the fresh flower. Those who want to use them as wedding decor or for special guests have to order them in advance from rare garland-makers in Swahili cities and towns.

Botanists, researchers, and local people fear the eventual extinction of the mkilua plant. In the meantime, despite its rarity, it continues to be an essential part of Swahili culture. Looking forward, protecting the species from further endangerment is critical to ensuring mkilua’s continued longevity.

Sources

¹Muhammed, Dr. Najya. (2014). Conservation And Cultural Aspect Of Mkilua Fragrans Verdc. At The Kenyan Coastal Lowlands. International Journal of Scientific & Technology Research Volume 3 194-198.
²Verdcourt, B. (1970). A New Genus of Annonaceae from the East African Coastal Forests. Kew Bulletin, 24(3), 449-453. doi:10.2307/4102847
³Cosiaux, A., Couvreur, T.L.P. & Erkens, R.H.J. 2019. Mkilua fragrans. The IUCN Red List of Threatened Species 2019: e.T34835A132678733. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T34835A132678733.en. Downloaded on 16 January 2021.
⁴Lilechi D. Baraza , Mayunga H. H. Nkunya , Stephan A. Jonker , Slim R. Juma & Reiner Waibel (2006) C18 tetraynoic fatty acids and essential oil composition of Mkilua fragrans , Natural Product Research: Formerly Natural Product Letters, 20:2, 187-193, DOI: 10.1080/14786410500045960
⁵Odalo O. J., Omolo M. O., Malebo H., Angira J., Njeru P. M. , Ndiege I. O., Hassanali A. (2005) Repellency of essential oils of some plants from the Kenyan coast against Anopheles gambiae; Acta Tropica; 95(3):210-8
⁶IUCN. 2019. The IUCN Red List of Threatened Species. Version 2019-3. Available at: www.iucnredlist.org. (Accessed: 10 December 2019)
⁷Mwampamba, T.H. 2007. Has the woodfuel crisis returned? Urban charcoal production in Tanzania and its implications to present and future forest availability. Energy Policy 35: 4221-4234.