• fast-growing, tall evergreen tree
  
• develops a strong root base that can kill or impede growth of surrounding plants
  
• survives drought, short periods of flooding and poor soil conditions
  
• primary use: wood
  
• other uses: flowers attract bees for honey production; oil in leaves used in medicines and perfumes; deep roots provide good protection against the wind

2. acacia
Scientific Name: Acacia senegal L.
Popular Names: Acacia Olo, Donkey Ears
Tree Family: Mimosaceae

• resembles a shrub more than a tree
  
• survives dry winds, sandstorms, high temperatures and drought
  
• fallen leaves decay and nourish topsoil
  
• large lateral root system secures the soil and provides it with nitrogen
  
• primary use: production of high quality "gum arabic" that is used in meals, medicines, cosmetics and crafts and is an important export product for the Sahel region
  
• other uses: wood and charcoal production (although low yield); flowers attract bees for honey production; bark and leaves used in medicines and to provide food for livestock

3. acacia
Scientific Name: Acacia albida Del.
Popular Names: Apple-Ring Tree
Tree Family: Mimosaceae

• very important to Sahel region (protected, included in local customs)
  
• large tree (up to 25 metres) - trunk can be more than one metre wide
  
• survives prolonged dry periods (several years), flooding, high temperatures and has no particular nutrient requirements
  
• deep root system reaches water and minerals at lower soil levels
  
• leaves rich in nutrients are shed during rainy season, fertilizing top layers of the soil
  
• primary use: most important food supply for animals (seed pods are extremely nutritious)
  
• other uses: mature trees provide shade in dry season; seeds used for human food in times of famine; softwood suitable for tools, bowls, boats, etc.; wood ashes used in soap production; flowers attract bees for honey production; various parts of the tree used in medicines

• size varies widely depending on site (rainfall, temperature, soil quality)
  
• survives on uncultivated land
  
• now extinct in certain areas of Sahel and Sudan regions where it once grew
  
• primary use: provides valuable wood and charcoal
  
• other uses: wood is hard and difficult to cut and saw, but easy to carve for arts and crafts; young leaves, shoots and pods provide food for livestock; seeds are used as a spice; barks, leaves and roots are used in many different types of medicines

5. leucaena
Scientific Name: Leucaena leucocephala (formerly Leucaena glauca)
Popular Name: Miracle Tree, and many others that vary by country
Tree Family: Mimosaceae

• two types: "common", shrub-like leucaena (low yield, less value); fast-growing "giant" leucaena up to 18 metres high (better forage and wood)
  
• requires warm temperatures (even light frost damages leaves)
  
• develops deep root system, giving it a high tolerance for dry periods
  
• mature trees can survive short periods of flooding
  
• has specific soil and nutrient requirements (neutral soil, phosphorus, calcium)
  
• susceptible to root competition from surrounding plants until canopy develops
  
• young growth and seeds can be toxic to livestock and humans
  
• primary use: provides nutritious animal forage, but can be toxic in large quantities
  
• other uses: every part of the tree is used; foliage makes nutritious mulch; larger trees provide hard wood for charcoal and timber; shrubs provide live fencing, shade for ground crops, natural support for climbing plants and protection against the wind

• thrives in dry climates and low fertility soils
  
• produces a yellowish green/yellow fruit that contains a natural pesticide in its seed kernels
  
• can slow down the loss of nitrogen in the soil
  
• primary uses: pest control and wood
  
• other uses: shade; various medicinal purposes