Blackberry Jam Fruit - Randia formosa (Jacq.) K. Schum.
Fruit and leaves
Fig. 1
Fruit and leaves

Flesh of the fruit
Fig. 2
Flesh of the fruit

Fruit, foliage, seeds
Fig. 3
Fruit, foliage, seeds

Fig. 6

Flowers and leaves
Fig. 7
Flowers and leaves

Leaves and fruit
Fig. 12
Leaves and fruit

Blackberry Jam shell
Fig. 19
Blackberryjam fruit shell

Rosenbergiodendron formosum seed-wet
Fig. 20
Rosenbergiodendron formosum seed-wet

Growth habit
Fig. 21
Growth habit, Fruit & Spice Park, Homestead, Florida, USA

Blackberry jam bush
Fig. 22
Fruiting plant at The Kampong, Coconut Grove, Florida, USA

Scientific name
Randia formosa (Jacq.) K. Schum.
RAND-ee-uh for-MOH-suh
Common names
Blackberry jam fruit, raspberry bush, jasmin de Rosa
Gardenia mussaenda L.f.; Genipa mussaendae (L.f.) Baill.; Mussaenda formosa Jacq.; Randia mussaenda (L.f.) DC.; Ronbergiodendron formosum (Jacq.) Fagerl.; R. orinocensis Rusby; Solena mussaendae (L.f.) D.Dietr. 3
Central and South America 2
Great for container growing
4-5 ft (1.2-1.5 m) tall in the ground; 3-4 ft (0.9-1.2 m)in container
Plant habit
Small evergreen bushy shrub; compact 1
Growth rate
Pruning requirement
Can be trained into a miniature tree 1
1.5-2 in. (3.8-5.1 cm); star shaped; very fragrant, tubular; white 1
Yellow; small in size; taste like blackberry jam 2
Light requirement
Full or partial sun; will flower and fruit in filtered light 1
Soil tolerances
Prefers well drained acidic soil
PH preference
Acidic soil; leaves may turn chlorotic in alkaline soils (Fig. 5 )
Drought tolerance
Reported to be drought tolerant 1
Cold tolerance
Relatively cold hardy; said to withstand as low as 26° F (-3.3° C) 1
Invasive potential *
None reported
Pest resistance
Known hazard


Central and South America

An interesting plant for fruit tree collectors and those in search of fragrance. Randia formosa is a shrub related to Gardenias. It’s a small bushy shrub to 2m+ and produces fairly large, fragrant, ornate white flowers and is hardy. It enjoys full or partial sun and likes acidic soil. To lower pH: Both ammonium sulphate and ammonium nitrate acidify the soil, but ammonium sulfate is much more acidifying.
Generally, the plant is fairly easy to grow and can make a container specimen in colder areas. Propagation by seed. The University of Guam say it is a primary windbreak species. 2

Extract from Tomas B. Croat BCI Descriptions
(Jacq.) K. Schism. in Mart., Fl. Brazil. 6(6):342. 1889
Ronbergiodendron formosum (Jacq.) Fagerl.

Dioecious shrub or small tree, unarmed, widely branched; stems glabrous in age, slender. Leaves clustered at ends of small lateral branches; stipules short, broadly triangu­lar, often ± scoop-shaped, acute, 1.5-3 mm long, brown, persisting below leaf clusters; petioles obscure or to 1 cm. long; blades oblanceolate-elliptic, acuminate, attenuate and decurrent at base, mostly 3-11 cm long, 1.5-3 cm wide, sparsely pubescent and dark green above, duller and more densely pubescent below. Flowers single at branch, ends, densely sericeous; calyx 13-20 mm long, lobed, persisting in fruit, the lobes 5, linear, 8-10 mm long; corolla tubular, 11-19 cm long, the tube greenish, papillose inside at apex, soon becoming velutinous in upper part, then glabrous, the lobes 5, white, 3-5 cm long, tapered to a slender tip; filaments adnate to tube; anthers 5, ca 5.3 min long, attached at flared apex of tube; style with ascending trichomes near apex; stigma broadly bilobed, held slightly above anthers. Fruits baccate, ± spherical, to 25 mm diam, dark green, with several broad white bands extending from apex to middle or beyond, sparsely covered with appressed trichomes; seeds num­erous, flattened laterally, stacked in 4 rows, white. Croat 11296,11888. 4

Rosenbergiodendron formosum leafLeaf formationChloritic leaves
Fig. 3 Fig. 4 Fig. 5 

Fig. 4. Rosenbergiodendron formosum leaf
Fig. 5. Leaf formation
Fig. 6. Chlorotic leaves (over-watering/ alkaline soil)

Flowers are gardenia-like and have pleasant sweet fragrance, although not as strong as gardenias. When in bloom, the bush is all covered with star-shaped flowers. 1

Flower budRosenbergiodendron formosum flowerFlowerFlower and leaves
Fig. 8 Fig. 9 Fig. 10 Fig. 11

Fig. 8. Rosenbergiodendron formosum flower bud

A genus of about 100 species of shrubs and trees, from tropical and warm regions of the Americas, R. formosa, unlike most members of this tropical to subtropical genus, usually lacks spines on its upright stem and can be cultivated in temperate climates. 5
Olive-shaped yellow fruits are woody shelled, about 1" size and look like small loquats. They can be easily crushed between teeth. The fruit contains two cells with small flat seeds surrounded by sweet black soft pulp tasting like "blackberry jam", beloved of children and adults. 1

Rosenbergiodendron formosum immature-fruitRosenbergiodendron formosum immature-fruit and leavesRosenbergiodendron formosum mature fruit dried
Fig. 13 Fig. 14 Fig. 15
Randia formosaBlackberryjam fruit fleshFruit, flesh and seeds
Fig. 16 Fig. 17 Fig. 18

Fig. 13,14. Rosenbergiodendron formosum immature-fruit and leaves
Fig. 15,16. R. formosum fruit
Fig. 17. Blackberryjam fruit flesh
Fig. 18. Fruit, flesh and seeds

A small 3 ft plant in 3 gal container can bear as many as 25-30 fruit at a time. Blooming/fruiting period continues for a few months, new flowers appear while the first fruit start to ripen. 1

Attract nocturnal moths for pollination. 1

Starts fruiting in young age - 1-1.5 year from seed. 1-3 gallon container plants start blooming and fruiting when they reach about 2 ft tall. 1

Growing your Blackberry Jam Fruit Seed

This species is reported to be drought tolerant, however, it requires regular watering until the plant is well-established. Young plants easily droop leaves if underwatered, they may even loose all the leaves overnight if the soil gets too dry! However, the plant usually recovers very quickly and new growth comes in a few days to a week. 1
During cold period, watering should be reduced, otherwise leaves may become chlorotic
(Fig. 5 ). Randia formosa is very sensitive to over-watering particularly during cool season. 1

Food Uses
You don't have to make a preserve with this fruit - the fresh pulp tastes exactly like Blackberry Jam. Yet it's not too sweet and actually tastes even better than any preserve. When you see the shrub all covered by yellow fruit, you are anxious to pick, crack open all of them, and suck out the sweet and tasty exotic pulp... This is one of those fun rare fruits than one never gets tired of! 1

The Blackberry Jam Fruit is definitely a conversation piece, and tasting a "blackberry jam" from a gem of your rare fruit collection will always bring fun time for your family, friends and garden visitors. 1

List of Growers and Vendors

1 "Randia formosa. Fragrance and fresh Blackberry Jam." Top Tropicals Tropical Plant Catalog. Web. 6 Jan. 2015.
2 Backhouse, Sheryl. "Blackberry Jam Bush: Randia formosa." Sub-Tropical Fruit Club of Qld. Inc Newsletter Aug. Sept. 2007. Web. 12 Nov. 2015.
3 "Rosenbergiodendron formosum (Jacq.) Fagerl." United States Department of Agriculture. Agricultural Research Service, Beltsville Area. Web. 12 Nov. 2015.
4 Croat, Thomas B. "Randia Formosa." Flora of Barro Colorado. 1978. Stanford University Press, ISBN 0-8047-0950-5. Web. 14 Nov. 2015.
5 "Randia formosa (Jacq.) K. Schum. (Jasmin de rosa, blackberry jam fruit)." N.d. 14 Nov. 2015.


Fig. 1,2,3,4,12,18,21 Jackson, Karen. "Blackberry Jam Fruit Series." 2014. Fruit & Spice Park, Homestead, FL, USA. Web. 14 Nov. 2015.
Fig. 5,6,16,17 Randia formosa - Fragrance and fresh Blackberry Jam. N.d. Top Tropicals Tropical Plant Catalog.  Web. 6 Jan. 2015.
Fig. 7 Rodd, Tony. Flowers and leaves. N.d. Under (CC BY-NC-SA 3.0). Web. 12 Nov. 2015.
Fig. 8,9,10,11,13,14,15,20 Paton, Steven. Rosenbergiodendron formosum. 2003-2006. Environmental Sciences Program, Smithsonian Tropical Research Institute. Web. 12 Nov. 2015.
Fig. 19 Robitaille, Liette. "Blackberry Jam Bush Series." 2015. JPEG file.
Fig. 22 Daderot. Fruiting plant at The Kampong, Coconut Grove, Florida, USA. N.d. Public domain. Web. 12 Nov. 2015.

UF/IFAS Assessment of Non-native Plants in Florida's Natural Areas

Published 6 Jan. 2015 LR. Last update 27 Mar. 2017 LR
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