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  Bombax ceiba L.
Vernacular name  Elavu, Pulamaram, Mullilavu, Poola (Malayalam); Mulelavu, Illavam (Tamil); Semal (Hindi); Burla, Sauvi (Kannada) (Chacko et al., 2002).
Common name  Silk cotton tree, Indian bombax (Chacko et al., 2002); Red silk cotton tree, Cotton tree (Bose et al., 1998); Semul.
Synonyms  Bombax malabaricum DC., Salmalia malabarica (DC.) Schott & Endl. (Bose et al., 1998; Sasidharan, 2004); Gossampinus malabarica (DC.) Merr. (Chacko et al., 2002). Bombax heptaphyllum Cav., (Gamble, 1922).
Family  Bombacaceae
Subfamily 
Origin 
Distribution  Distributed throughout India in deciduous forests and ever green forests. In Kerala it occurs in Thrissur, Palghat, Ernakulam and Trivandrum districts. Widespread in the subcontinent, in the Himalaya up to 1300 m, also in Myanmar and Sri Lanka and as far as Northern Australia (Sahni, 2000).
Description  Fast growing, large sized armed deciduous tree reaching a height of 40 m and diameter of 191 cm with whorled horizontal branches; trunk of young tree is covered with stout, conical, prickles, mature tree develop large buttresses (Bose et al., 1998; FRI, 1981; Chacko et al., 2002).
Flowering season  January to March (Brandis), February to March (Bose et al., 1998).
Fruiting season  April to May (Sahni, 2000).
Flowers  Flowers scarlet, reddish-orange and shades of red and orange, rarely yellow, 8 to 12 cm long; calyx leathery, cup shaped, slightly lobed; petals 5, thick; stamens many; filaments in 5 to 6 bundles opposite the petals (Bose et al., 1998). Flowers numerous, large, 10-30 cm in diameter, fleshy bright crimson, yellow or orange, clustered at the end of branches.
Fruits  Fruit is a capsule, oblong, tapering to both ends (Bose et al., 1998); 10 to 18 cm long, valves woody, lined with silky hairs within. Fruit ovoid, 5 angled, short stalked, downy 10-15 cm long, black when ripe (Sahni, 2000).
Fruit type  Capsule.
Seeds  Many, obovoid, smooth, 6-9 mm long, oily, with dense silky hairs. Seeds small. Innumerable, embedded in silky cotton dispersed by wind (Sahni, 2000).
Seed length  6-9 mm (Chacko et al., 2002).
Seed width 
Seed thickness 
Seed weight  23,986 to 52,911seeds/kg (Sen Gupta, 1937 from Chacko et al., 2002); 11,000 to 22,000 seeds/kg (Kindt et.al., 1997; Chacko et al., 2002); 2,14,000 to 3,85,000 seeds/kg (Carlowitz, 1991; Chacko et al., 2002).
Seed dispersal  By wind, Birds.
Seed Collection  Knock off the mature capsules just before they are about to open (Chacko et al., 2002).
Transportation of seeds  Capsules are gathered in cotton / polythene bags and transported to the processing centre at the earliest (Chacko et al., 2002).
Seed processing  Pods are dried under the sun until they burst. Care should be taken to prevent the seeds from being blown away. Seeds are separated from the floss by churning in a drum using a locally made churn stick (Chacko et al., 2002).
Seed storage  Intermediate (Kindt et al., 1997); Orthodox (CABI, 1998). Put well dried seed in a polythene bag, seal, and store in a cool place for 1 to 2 years (Luna, 1996; Chacko et al., 2002).
Viability period  Up to 2 years (Chacko et al., 2002)
Seed emptiness  Low (Chacko et al., 2002).
Seed pre treatment  Soak the seeds in cold water (Kindt et al., 1997; Chacko et al., 2002).
Germination type  Epigeal (FRI, 1981; Chacko et al., 2002). 30oC is the optimum temperature for germination (Varela et al., 1999).
Germination percentage  14 to 100 (Sen Gupta, 1937; Chacko et al., 2002).
Germination period  5 to 33 days (Sen Gupta, 1937; Chacko et al., 2002).
Nursery technique  Seeds are sown in germination trays containing vermiculite and watered regularly. The seedlings are potted in polybags of size 22.5 cm x 17.5 cm. The seedling develops vigorous root system and therefore the potted seedlings need frequent shifting and root pruning (Chacko et al., 2002).
Method of propagation  By seeds and budding (Venkatesh et al., 1978).
Vegetative propagation 
Pests  Moderate to heavy. The bug Dysdercus cingulatus Fb.(Heteroptera: Pyrrhocoridae) cause serious damage to seeds in the field. Nymphs and adult of this insect feed by sucking sap from pods, fruits and seeds (Beeson, 1941 from Chacko et al., 2002).
Diseases  Moderate (40 to 66.5%); 20 fungi, actinomycetes and a bacterium are recorded. Cercospora sp., Fusarium sp., Pestalotiopsis sp., Alternaria sp. are the important field fungi recorded on seeds (Sharma and Mohanan, 1980; Mohanan and Anil Chandran, 2001 from Chacko et al., 2002).
Medicinal properties  Leaves, stem bark, root of young plants, flowers, fruits, and seeds have different medicinal uses in indigenous system of medicine (FRI, 1981 from Chacko et al., 2002). The roots and bark are emetic, astringent, tonic, haemostatic, aphrodisiac in nature and useful in diarrhoea and dysentery.
Uses  It is one of the first trees to appear on alluvial ground. The inner bark yields a good fibre suitable for cordage. Fruit yield cotton. Floss from fruits and seeds used for stuffing pillows and mattresses. Wood is used in match industry, packing cases, brush candles, boarding, planking, shingles, toys etc. Immature calyx is used as vegetables (Chacko et.al.,2002).
Wood properties  It is very soft, light, straight grained, even and coarse textured. The wood is creamy white but turns pale greyish brown on exposure. Heartwood is usually absent but in some logs occasionally central portion is reddish brown in colour. Average air dry weight 385 kg/m3. Wood white when fresh cut, turning dark on exposure, very soft, perishable; no heartwood; no annual rings. Pores very scanty, very large, often oval or divided into compartments. Medullary rays fine to broad, numerous, not prominent. Pores and silver-grain prominent on a vertical section (Gamble, 1922).
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