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  Alnus nepalensis D.Don
Vernacular name  Alnus (Malayalam); Alnus (Tamil); Alnus (Kannada) (Chacko et al., 2002).
Common name  Nepalese alder (Chacko et al., 2002; Troup, 1921). Indian alder, Udis.
Synonyms  Alnus mairei A. Leveille, Clethropsis nepalensis Spach. (Chacko et al., 2002).
Family  Betulaceae
Subfamily 
Origin  Burmese hills.
Distribution  Native of Burmese hills and the Himalayas from 1000 m to 3000 m above sea level. Planted extensively in the hills of Northern and Southern India (Chacko et al., 2002).
Description  Fast growing, shade tolerant, large deciduous tree with 30 m height, and breast height diameter of 80 cm with straight cylindrical bole (Chacko et al., 2002).
Flowering season  April to June (Bose et al., 1998). September to November (Troup, 1921).
Fruiting season  February to March (Troup, 1921). December to January (Sen Gupta, 1937; Chacko et al., 2002).
Flowers  Flowers in group of 5-12, subtended by both bracts and bracteoles, perianth 4-lobed, stamens 4. Male catkins slender to 12 cm in terminal drooping clusters. Female clusters cone-like, becoming woody (Sahni, 2000). Inflorescence axillary or terminal; male spikes: panicled, pendulous, 10-20 cm long; flowers in groups of 5-12, subtended by both bracts and bracteoles; perianth 4-lobed; stamens 4, with ciliate scales; female spikes: 6-10 mm long, in groups, pendulous; bracteoles 2-4; perianth absent; ovary 2-celled, 1 ovule in each cell (Bose et al., 1998).
Fruits  Ovoid, woody cone, 1-2.5 cm long. Cones 1.2-2.5 x 0.7 cm in erect clusters. Nutlet with a narrow papery wing (Sahni, 2000). Fruit, spikes, 12 x 7 mm, ovoid or cylindrical, short peduncled in lateral panicles (Chacko et al., 2002).
Fruit type  Cones.
Seeds  Nuts with a narrow membranous wing (Chacko et al., 2002; Troup, 1921).
Seed length  1 mm (Chacko et al., 2002).
Seed width 
Seed thickness 
Seed weight  5,29,110 seeds/kg (Sen Gupta, 1937; Chacko et al., 2002); 28,57,142 seeds/ kg; 2,18,000 to 30,00,000 seeds /kg (Carlowitz, 1991; Chacko et al., 2002).
Seed dispersal  Wind dispersal.
Seed Collection  Fruits are collected from the trees by lopping off the branches before they dehisce (Chacko et al., 2002).
Transportation of seeds  Fruits collected in plastic / cotton / polythene bags are packed and transported. Tight packing may be avoided if the fruits are moist (Chacko et al., 2002).
Seed processing  Cones are sun-dried and beaten with a stick to release the seeds. Care should be taken during extraction of seeds as they are easily blown by wind (Chacko et al., 2002).
Seed storage  Orthodox (Napier and Robbins, 1989; CABI, 1998). Seeds can be stored in sealed polythene bags, plastic container and kept in a cool place for more than one year (Napier and Robbins, 1989).
Viability period  Seed kept in unsealed containers absorbs moisture very quickly and loose viability in a few months (Napier and Robbins, 1989; Chacko et al., 2002).
Seed emptiness  Low (Chacko et al., 2002).
Seed pre treatment  Not necessary (Chacko et al., 2002).
Germination type  Epigeal (Chacko et al., 2002).
Germination percentage  70 (Carlowitz, 1991; Chacko et al., 2002).
Germination period  7 to 30 days (Napier and Robbins, 1989; Chacko et al., 2002).
Nursery technique  Seeds are sown in plastic trays containing vermiculite and watered. The seedlings are potted in polythene bags of size 10 x 20 cm when they have 2 to 4 primary leaves and should be maintained under shade. The growth of seedlings is slow (Chacko et al., 2002).
Method of propagation  By seed.
Vegetative propagation 
Pests  No information (Chacko et al.,2002).
Diseases  Eleven fungi, bacteria and actinomycetes were recorded. Alternaria sp., Chlamydomyces palmarum are the important fungi recorded (Mohanan and Anil Chandran, 2001; Chacko et al., 2002).
Medicinal properties  The astringent alder is employed most often as a mouthwash and argle for tooth, and throat problems. Leaves are used to help reduce breast engorgement in nursing mothers. A decoction of bark is used for the treatment of external bleeding and to heal wounds (Sahni, 2000).
Uses  Wood yields 39% pulp suitable for news print production and for ordinary wrapping and writing paper. Leaves are sometimes used as fodder. The bark contains 7% tannin, used in dyeing (Bose et al., 1998).
Wood properties  Wood light pinkish brown, soft, light and even-grained (Troup, 1921).
References  Get ...
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