Accession Count: 0
Common Name:
robusta coffee, Congo coffee tree
Family Name:
Rubiaceae
Botanical Name:
Coffea canephora
Sub Species:
Variety:
Forma:
Cultivar:
Characteristics:
The robusta coffee is a shrub or small tree that can grow to heights of up to 12 m (about 40 ft) but is typically a bit shorter than that under cultivation (1, 5). Its canopy being rounded in habit is held up by multiple light brown branches instead of a singular trunk (1). Its leaves are oppositely arranged along the stems, 8-24 cm long, elliptical in shape, and glabrous or waxy (1). Leaf margins are undulated (wavy) l and the leaf blade has prominent bulges in between leaf veins (1, 2). Its white flowers are dioecious, less than 2 cm wide and are borne on domed cyme inflorescences in the axils of leaves (1). Initially, the corollas of the flowers appear tubular, but once tepals open, the corolla reveals 5-6 petals (tepals) fused at the base and splaying out to produce a salverform-funnel shaped perianth (1). Fruits are red drupes that are 0.9-1.7 cm long and wide, cherry red when ripe, and bear singular smooth greenish brown seeds inside (1).
Compound:
Cof can
Geographic Origin:
Tropical Western, Sub-Saharan Africa
Ecozone Origin:
Afrotropic
Biome Origin:
Natural History:
As one of its common names suggests, the Congo coffee tree is native to tropical regions in western and central sub-Saharan Africa. (3). This plant has been introduced to countries in South America, Central America and Asia and is commonly cultivated in plantations for its coffee beans that it produces (3, 4). The earliest report of the Congo coffee tree being cultivated for its coffee beans reports back to the 1870s in the Democratic Republic of Congo within its native region, although may have been cultivated for some time before that (3). It was not until the early 1900s that the Congo coffee tree was recognized for its potential as a more sustainable option for commercial coffee production compared to the typical cultivated species, Coffea arabica, which at the time was the main source of coffee beans (3). In its native range, it can be found in various environments that range from dry humid forests, evergreen forests, and even in dense rainforests (3, 5). It normally resides in low elevations that range from 50-1,500 m (150-4500 ft) (3). This species is known for its resilience to environmental challenges and is not susceptible to diseases and pests (3).
Cultivation Notes:
This plant is cold hardy to USDA zones 10-11 (7). It is not tolerant of temperatures that consistently stay below 5°C (50F) as this would lead to stem damage or plant death (5). This plant succeeds in loamy well-drained soils but can tolerate temporary periods of waterlogging (5). Soil that is higher in acidity and in the pH range from 5-6 would benefit this plant but it can endure soils with higher alkalinity (5). The robusta coffee generally needs moderate watering; including supplementary water in climates where temperatures exceed 36°C (5). However, it can potentially tolerate some periods of drought (up to a month) (5). The most common form of propagation for this plant is by seed (5). It is recommended to propagate fresh or recently harvested seeds as these have higher viability and germinate faster (5).
Ethnobotany:
Currently, the robusta coffee is most often cultivated in Vietnam, Brazil, Indonesia, Uganda, India, and Côte d’Ivoire - regions producing 20% of coffee beans worldwide (2, 3). The robusta coffee tree also has other key medicinal uses besides being heavily cultivated for commerciality. The seeds of this plant contain caffeine, which can be used as a stimulant for pain relief, increased alertness and physical activity, and can even control vomit (5). It has also been traditionally used to combat flu, fevers, headaches, asthma, jaundice, and other various ailments (5). Its coffee beans can also be used to produce a sustainable alternative to compostable plastic (5). The most common method to process the coffee beans from the robusta coffee tree can be referred to as “The dry method” (6). The first step to this process is sorting and cleaning the harvested fruits by separating the ripe cherries from overripe or underripe cherries and other plant material like leaves or twigs (6). After that, the cherries are left out to dry in the sun for up to 4 weeks on large platforms (6). Machines can be used to accelerate the drying process after the fruit has dried for a couple of days in the sun (6). The dried cherries are then sent to the mill for a hulling process which consists of the removal of the dry fleshy layers of the fruits to be removed, exposing the seeds ready to be sold (6).
Height:
20 - 50 feet
Width:
20 - 50 feet
Growth Rate:
Moderate Growing
Grow Season:
Spring
Flower Season:
Spring
Color:
White
Function:
Shade
Spread:
Non-spreading
Allergen:
Allergenic
Invasive:
Benign
Toxicity:
Benign
Hardy:
Semi-hardy
Water Use:
Moderate Water Use
Citations:
1. The World Flora Online, Retrieved January 28, 2025
2. National Parks: Flora & Fauna Web, Retrieved January 28, 2025
3. World Coffee Research, Retrieved January 20, 2025
4. Kew: Plants of the World Online, Retrieved January 28, 2025
5. Useful Tropical Plants, Retrieved January 28, 2025
6. Institute for Scientific Information on Coffee, Retrieved January 28, 2025
7. World of Flowering Plants, Retrieved January 28, 2025
