Rosenbergiodendron formosum
| Blackberry jam fruit (Rosenbergiodendron formosum) | |
|---|---|
| Scientific name | Rosenbergiodendron formosum |
| Common names | Blackberry jam fruit; Randia formosa |
| Genus | Rosenbergiodendron |
| Family | Rubiaceae |
| Order | Gentianales |
| Native range | Colombia, Ecuador, Panama and Venezuela |
| Habit | Compact evergreen shrub |
| Light | Full sun to partial shade |
| Soil | Well-drained acidic soil |
| Propagation | Seed |
Rosenbergiodendron formosum is the accepted name for the blackberry jam fruit, with Randia formosa among its documented synonyms.[1] GBIF places the species in Rubiaceae and returns an accepted species match with high matching confidence.[2] Its native range is listed in Colombia, Ecuador, Panama and Venezuela; Trinidad and Tobago is listed as an introduced range.[1]
Description[edit | edit source]
This is a compact evergreen shrub with fragrant, tubular white flowers.[3] In cultivation it can be kept in a container, making it a useful candidate for growers who need to move a tropical fruit plant between protected and outdoor conditions.[3]
Cultivation[edit | edit source]
Soil and water[edit | edit source]
Horticultural guidance places the plant in well-drained acidic soil and describes container growing for this compact shrub.[4][3]
Sun and humidity[edit | edit source]
The available horticultural accounts describe full sun, bright light, or partial shade for this plant.[3][4]
Seasonal changes[edit | edit source]
The evergreen habit is associated with continued growth in warm conditions rather than a deciduous winter dormancy.[3] Flowering and fruit ripening may overlap, so a plant can carry flowers and developing yellow fruit during the same extended production period rather than offering only one sharply bounded crop window.[3]
Propagation[edit | edit source]
Seed propagation is the documented method for this plant.[3] The same horticultural account places seed-to-fruit timing at about 1–1.5 years in its reported growing example; treat that interval as an account-level observation rather than a fixed schedule for every climate, container, or plant.[3]
Flowering, fruiting, and harvest[edit | edit source]
The flowers are described as fragrant, tubular and white. A nocturnal-moth pollination association is also given, but that observation does not establish a universal pollinator requirement for cultivated plants.[3] Flowering and ripening can overlap, and the fruit is described as yellow when mature.[3]
A documented container-grown example, about 3 feet tall in a 3-gallon container, carried 25–30 fruits at a time.[3] That individual result is useful for judging the plant's potential in a container, but it is not a general yield expectation.
Fruit and uses[edit | edit source]
The fruit has soft, sweet pulp described as resembling blackberry jam, which explains the common name.[3] Its distinguishing description is the soft pulp and jam-like flavor comparison; fruit size, storage life and preparation methods remain unresolved.
Cultivars and selections[edit | edit source]
“Lady Fingers” is a nursery selection name attached to a long-fruited form described with fruit about 2 inches long and larger flowers.[5] Use the name only as a nursery-selection label, without treating it as a formally released cultivar or assuming comparative data for flavor, yield, climate adaptation or propagation.