#LoveYourCampus
Interactive Botanical tour
Point No. 3
Species: Jacaranda mimosifolia D. Don
Family: Bignonoaceae
 |
Being dubbed the ‘Jacaranda city’ it is safe to say not many people are unaware of the deciduous, lavender-blue foliage of the Jacaranda tree. The trumpet-shaped flowers make their guest appearance from late September until November, as their blooms form the spectacle of the year. A lesser known fact about these ‘fan favourites’ is that they aren't indigenous to South Africa, and in actuality originated in South America. Louis Celliers de Villiers (after which the UP sportsground LC de Villiers was named) brought Jacaranda seeds to be planted on and around Hatfield campus. Some of the Jacaranda trees on campus are remnants of the old town layout and are still the original trees planted when the Union Buildings was erected.
Description
Scientific name: Jacaranda mimosifolia
Pronunciation: jack-uh-RAN-duh mih-moe-sih-FOLE-ee-uh
Common name(s): Jacaranda
The Bignoniaceae family (Trumpet creeper family) consists of an astounding approximate of 700 flowering plants. They have compound leaves and the creeping forms have tendrils to attach to surfaces. Their funnel shaped flowers have five petals and grow in brightly coloured clumps.
The seeds form in a flat dehiscent disk-like structure that crack open when dry to release small winged seeds1.
Did you know?
The word ‘Jacaranda’ is believed to mean ‘fragrant’ in a native South American dialect2
History at University of Pretoria
Pretoria's claim to fame is not even from Mzansi! The French botanist, Antoine de Jusseau, described these Brazilian trees and gave them the name ‘Jacaranda’ in 1789. In the early 1800’s a horticulturist, Carl von Ludwig, brought Jacarandas to the Cape2. The first Jacaranda tree planted in Johannesburg is in Doornfontein. In 1888 a travelling nurseryman sold two Jacaranda seedlings to JD Cilliers, these are the first two Jacarandas planted in Sunnyside, and they can be visited to this day at Myrtle Lodge, Sunnyside.
Due to their beauty, many people suggested the streets of Pretoria should be planted with these trees. Frank Jameson aka. ‘Jacaranda Jim’ was famous for planting many Jacarandas in the streets in 1911. He died in 1956, and was buried under a Jacaranda tree in Pretoria with ‘Jacaranda Jim’ engraved in his headstone. The tree was promoted for being adaptable to our climate. It's estimated that the streets in and around Pretoria house more than 65 000 Jacaranda trees these days3! However, it is actually illegal to plant more Jacarandas, as they are classified as alien plants guzzling up all the town's water and are harmful to the environment and surrounding species. They can reach two hundred years in age, so before you start worrying about no longer seeing them, rest assured that there will still be Jacarandas in our streets for a long time. Jacarandas have become an important part of Pretorian culture, with even a radio station (Jacaranda FM) named after them. Most students will have heard of the fable that if a Jacaranda flower falls on you, you will pass all your exams.
In the 1920s, Jacarandas did not bloom in early September like they do today, they actually bloomed in mid-November. Within the past hundred years, Jacarandas have been blooming earlier and earlier in the year5. This is called a phenological shift and can be due to climate change. So, the other student fable that if you haven’t started studying before the Jacarandas start blooming you’ll fail doesn’t hold as true anymore (unless you’re very superstitious and committed).
In 2001, in a shocking turn of events, it was announced that these alien trees will all be removed (gasp) due to their heavy water usage. After announcing this, the producers of MNET’s Investigative TV show “Carte Blanche” had the public up in flames, but it became clear that Jacarandas were just part of an ingenious April fool’s day joke. This may have been a joke, but there has been a lot of debate throughout the years whether the trees should stay or go. It's evident that South Africans have a sentimental attachment to these fine-leaved trees.
Did you know?
It's not only the purple Jacarandas that have been planted in South Africa, but there are one hundred rare white Jacaranda trees planted in Groenkloof 4.
Images: Jacaranda trees in full bloom, UP, Hatfield campus.
Uses
Jacarandas were not only planted in the streets of Pretoria as ornamentals for aesthetics, but these urban forests also help to reduce dust pollution and provide mines with wood. The medicine man will be pleased to hear it also has various medicinal uses, the leaves can be used in baths to treat skin ailments such as acne the bark and roots can be used in treating syphilis. A watery extract from Jacaranda can be made, which has shown to have high antimicrobial properties against E. coli and Staphylococcus bacteria. Historically its bark has been used to alleviate nerve pain resulting from neuralgia. It is even scientifically proven that parts of the tree have anticancer properties that can be used in the treatment of Leukaemia.
Not only are Jacarandas valuable to people all around South Africa, they are valuable to scientists too! Jacaranda trees can be used to predict how climate change may affect the time of flowering of various plants. Social media posts strengthen the data on blooming times of Jacarandas across the region. When people post their vibrant pictures of Jacaranda trees, that is data that can be used to see how early the trees have bloomed that year6. So #PostYourJacarandas!
As temperatures rise over the centuries due to climate change, plants start blooming out of season. The major Jacaranda blooming events have been catalogued in newspapers for a long time, which serve as the perfect record of their flowering time. It has been found that Jacarandas have been blooming about two days earlier with an increase of 0.2 degrees temperature each decade from 1927 to 20197.When plants flower at the wrong time their pollinators may have a difficult time to pollinate them which poses a threat to the plant as well as the pollinator, and we all know how important pollination is for our wellbeing!
Text prepared by Arni le Roux & Tamara Venter, 2022 BOT 366 class.
Cited sources:
Copyright © University of Pretoria 2025. All rights reserved.
Virtual Campus
Get Social With Us
Download the UP Mobile App