**2.3** *Acacia farnesiana* **L.**

*Acacia farnesiana* L. belongs to family Leguminosae (Mimosoideae) and it is native to North America [46]. This tall semi-evergreen native shrub or small tree is commonly referred to as sweet acacia, Huisache, etc., with soft, medium-green feather-like, finely divided small leaves. The slightly thick stem is rich in chocolate brown or gray, with long and pointed needles. The small, puff-like yellow flowers are very fragrant, appear in clusters in late winter, and then occasionally spread out after each new flush, providing nearly four seasons of flowering. An area of about one hectare wills 91,500 kg of seeds yield, and the efficiency of oil per hectare is approximately 21,250 kg. The fruit is an elongated pod, 3 to 6 inches long, dry, and covered with hard skin, brown. Green color attracts birds; squirrels and other mammals have no obvious littering problems and stick to the trees, which is very beautiful. The long-lasting fruit has a smooth appearance and contains seeds cherished by birds and other wildlife (**Figure 3**).

**Figure 4.** *Albizzia julibrissin. (A) Plant; (B) seeds; (C) biodiesel; (D) glycerin.*

## **2.4** *Albizzia julibrissin*

One of the plants, *Albizzia julibrissin* (Mimosa) belong to Fabaceae, which contains non-edible seeds, can be evaluated for biodiesel production (**Figure 4**). *A. julibrissin* is a deciduous tree, wide and 12 m (40ft) high, but usually 3–6 m (10– 20ft), smooth bark, gray. *A. julibrissin* fruit comprises of lentil pods with enlarged seeds. Each pod is 8–18 cm long and 1.5–2.5 cm wide and can be observed from June to February. Each pod usually grows 5–10 elliptical seeds, about 1.25 in length. Some authors assert that mimosa produces many seeds [47]. *A. julibrissin* can produce 8,000 seeds per year. The average *A. julibrissin* seed per pound is 11,000 to 11,500 [48, 49]. Wind, gravity, and water are major contributory factors for dispersal of seeds and pods. *A. julibrissin* is native to Asia and found in Turkey, Azerbaijan, China, Japan, Taiwan, and other temperate regions, Bhutan in Asia, India, Nepal, Pakistan, Myanmar, Japan and other tropical areas [42, 50].
