Online Manual for the Forest Tree Seeds of Kerala

A Kerala Forest Department Funded Project


Dr. K Sudhakara
Professor & Head of the Department
Dept. of Silviculture & Agroforestry
College of Forestry, Kerala Agricultural University, Thrissur 680 656
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Scientific Name  Acacia melanoxylon R. Br.
Vernacular name 
Common name  Australian Black wood, Black wood Acacia (Bose et al., 1998; CSIR, 1948).
Synonyms  Racosperma melanoxylon (R.Br.) C.Martius
Family  Leguminosae
Subfamily  Mimosoideae
Origin  Native of Tasmania and South Australia (Bose et al., 1998).
Distribution  It was introduced to Nilgiris in 1840, where it has naturalised and has been extensively cultivated; commonly seen as roadside avenue in hills at an elevation of 1800-2400 m (Ram Parkash et al., 2002).
Description  A large unarmed evergreen tree, 18-36 m in height with straight trunk and pyramidal to cylindrical dense crown (CSIR, 1948; Henderson, 1995).
Flowering season  February to April (Bose et al., 1998).
Fruiting season  July to November (Bose et al., 1998).
Flowers  Flowers pale yellow in globose heads, 5 mm in diameter, arranged in short racemes (CSIR, 1948; Henderson, 1995; PIER, 2002).
Fruits  Reddish-brown, linear, flat, more or less curved and twisted into shape of letter C or S, narrower than leaves, seeds almost encircled by pinkish-red seed stalks (CSIR, 1948; Henderson, 1995).
Fruit type  Pod.
Seeds  Seeds flat roundish shiny black 2-3 mm long, almost encircled by pinkish-red seed stalks (aril) (Henderson, 1995; PIER, 2002).
Seed length 
Seed width 
Seed thickness 
Seed weight  65000 to 75000 seeds/kg (Srivastava et al., 2006).
Seed dispersal  Birds (ingest small seeds with pink-red aril), Primates (ingest seeds with pods) (Geldenhuys, pers.comm. 2003).
Seed Collection  Seeds are collected during July-November (Srivastava et al., 2006).
Transportation of seeds 
Seed processing  Pods are beaten with a stick, dried in the sun and the seed is extracted by trampling or flailing, and the clean seed is obtained by winnowing (Ram Parkash et al., 1998).
Seed storage  Orthodox seeds, can be stored in room temperature (Srivastava et al., 2006).
Viability period  1-2 years (Srivastava et al., 2006).
Seed emptiness 
Seed pre treatment  The hard coated seeds are pre-treated with hot water soak for 5 min to get good germination (CSIR, 1948). Acid scarification (Sulphuric acid) for five minutes is also found to increase the germination percent (Srivastava et al., 2006; Gupta and Thapliyal, 1974).
Germination type  Epigeal.
Germination percentage  60-70% (Srivastava et al., 2006).
Germination period  30 days (Khullar et al., 1991).
Nursery technique 
Method of propagation  By seeds and root suckers (CSIR, 1948).
Vegetative propagation  Coppice shoots develop from cut and damaged stems, and from damaged roots (Geldenhuys, pers.comm. 2003).
Pests 
Diseases  Leaf infection of nursery seedlings is caused by the Colletotrichum state of Glomerella cingulata, and shoot dieback of 2 yr old plant caused by Fusarium semitectum [F. pallidoroseum] (Mohanan and Sharma, 1988).
Medicinal properties 
Uses  The timber is useful for cabinet and constructional work. It is also used for bent work, boat building, and for tennis racquet frames. It makes a good roadside tree in USA and the wood is little inferior to black walnut for furniture making (Bose et al., 1998).
Wood properties  The colour of the wood varies from light brown to dark brown. The wood is strong and moderately hard. The heartwood is dark brown and beautifully mottled, shining and even grained. Sapwood and heartwood of Acacia melanoxylon possess particleboard properties. Heartwood had higher content of extractives and lower pH-value than sapwood. As the amount of heartwood in the sapwood/heartwood particle mixture increased, the physical-mechanical properties of particleboards improved, except for internal bond (IB). Particle boards with 100% heartwood presented the highest MOR and MOE values, and the lowest swelling and water absorption values (Pelen et al., 1998).
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