Bamboo and Rattan/Rattan/Course-1 Unit-3

Distribution:
Rattans are largely concentrated in South East Asia, in 10 genera with 574 species ( H. Singh & C.T. Yuan, 1999). The greatest diversity is in Malay Peninsula and Borneo. In India, the sub family Calamoidae comprises 4genera and over 60 species. The genera includes Calamus, Daemonorops, Korthalsia, and Plectcomia, concentrated in Western Ghats, Andaman and Nicobar Islands and North Eastern region, of which 30 species are endemic to India(Basu 1985). The rattans constitute an integral part of the tropical forest eco system largely confining specifically to moist shady habitats. They are mainly distributed in tropical, sub tropical and lower temperate belts in these regions. The forests in which it is seen are Evergreen, semievergreen, moist deciduous or subtropical evergreen types. They are rare in dry deciduous forests.

Which are the main centres of distribution in India?
Out of the three major centres of rattan distribution in India, western ghats has only one genus Calamus with 21 species (Renuka1992, Lakshmana1993)). Andaman & Nicobar Islands is represented by 3 genera with 18species (Renuka1995). The genera here are Calamus (11 species), Daemonorops (5 species) and Korthalsia (2 speceis) Remarkably Korthalsia is naturally found only in Andaman & Nicobar islands in our country. Northeast region of India comprises 24 species under 3 genera (excluding Zalacca) viz., Calamus(15 species with two varieties, Daemonorops (1 specie) and Plectocomia (4 species) (Sunny Thomas 2002). In India the genus Plectocomia is restricted to northeast India. Thus we find Calamus in all the regions, Daemonorops in Andamans and Northeast India. But Korthalsia only in Andamans and Plectocomia only in Northeast. Needless to mention the highest diversity is in northeast Indian states.

Where do rattans grow naturally?
Most of the species, except few like C. leptospadix, C. acanthospathus, C. gracilis, and P. assamica are confined to the low hills and plains (below 1000m). Species like C. acanthospathus and P. himalayana are confined to the high mountain range in the sub tropical and lower temperate region (1700-2300 m). Alam M.K.(1991) reported that C. viminalis ''var. fasciculatus'' grows in the dry soils and mixed deciduous forests in Bangladesh. Prain (1903) reported two species C. tenuis and D. jenkinsianus from the northern part of the mangrove forest of the Sunderbans. But usually rattans are not found in mangrove vegetation. The habitat of C. leptospadix ranges from 100m-1700m MSL. Rattan species occur mainly in forest habitats. But they also occur in riverine forests and sometimes, even extents to areas outside forests such as river and tank beds and edges of paddy fields etc. Occurrence of rattans in private home gardens either natural or cultivated is very less. As mentioned earlier rattans generally prefer moist shady areas. They are indicative of good forest vegetation in many instances. Species like Calamus tenuis can grow in open or partially open areas with sandy loam soil.

How the cane is utilised?
Rattans are the source of raw materials for furniture, handicraft and other industries. They are also used very intensively for a wide range of purposes, such as cordage, raw materials for baskets and mats, thatch, medicine, religious rituals etc.

Are all cane species commercially used?
Due to obvious reasons all the rattans are not commercially used. The reasons could be their rarity, poor quality or unfamiliarity with species by the users, inaccessibility or prohibitive transporting cost etc. In all there are 21 species of commercial importance which means these are more used as raw material for various cane products. Some of these are Calamus flagellum, Calamus leptospadix, Calamus gracilis, Calamus acanthospathus, Daemonorops jenkinsiana, Calamus nambariensis, Korthalsia laciniosa, etc. Commercial utility is largely based on the grading parameters listed below. The applications depend on the different grades.

Grading:
The grading of cane is based on thickness and the quality, and based on these the canes of the state can be classified into three categories, thin, medium and thick canes. (Lakshmana 19, Thomas et al. 1998). Inter nodal length also plays an important role in grading. If the inter node is longer; it is easy to work with the canes.

Identification:
How do we identify rattans?

There are several characters that help in identifying the canes to group, genus or species level.

Rattans (canes) are climbing palms. Thus they have all characters of members of the palm family. They can be easily recognized by their climbing character and profusely thorny/ spiny nature. Further their fruits have a series of scales that cover the seeds, which are arranged in definite rows. Identification of particular genus is easier based on characters like broad serrate rhomboid leaflets indicate Korthalsia. Similarly presence of ants in the leaf axils is a crude indication to Korthalsia. Plectocomia on the other hand are having terminal inflorescence and are haplaxanthic ie once flowering and then the plant dies. A large boat-shaped bract subtending the inflorescence is suggestive of the genus Daemonorops. Within the genus species can be identified with the help of characters like cluster forming or non-cluster forming, the thickness of stem large medium or small, less thorny ones like (Calamus erectus, C. khasianus), prominence of  knee (Calamus nambariense, C. erectus, etc) or absence of knee (C. hookerianus), cirrate ( Daemonorops jenkinsiana, Calamus tenuis, ) flagellate (Calamus leptospadix, C. gracilis etc) colour of sheath like the reddish brown (Calalmus nambariense), presence of tomentum on the rachis (Calamus leptospadix),  clustering of leaflets(C. gracilis) or  equidistant regular arrangement (C. floribundus) and so on..