Discovery of two rare and threatened tree species from myristica swamps of uttara kannada, karnataka

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The discovery in Uttara Kannada district of two rare and threatened tree species, considered hitherto endemic to the Western Ghats south of the Palghat gap, and feared to be extinct at one time, throws up before us fresh questions related to conventional approach to conservation. These two tree species viz. Madhuca bourdillonii (Gamble) Lam. and Syzygium travancoricum Gamble, have been discovered in some of the relic evergreen forest patches of Uttara Kannada in central Western Ghats.

Both the tree species occur in the vicinity of some of the Myristica swamps of the district. The Myristica swamps are reported as highly threatened relics of primeval swamps of the Western Ghats by Chandran & Mesta (2001). Of the characteristic tree species exclusive to these swamps are very rare and threatened ones belonging to Myristicaceae, one of the most ancient families of flowering plants. The famous spice tree nutmeg (Myristica fragrans), a native of the Mollucas Islands, is a member of this family. Some species of wild nutmeg trees, endemic to the evergreen forests of South Indian Western Ghats, are exclusive to the swamps. The most striking of them are Myristica fatua var. magnifica (Bedd) Sinclair and Gymnacranthera canarica (King) Warburg. The Myristica swamps are found usually at altitudes less than 600 m. Recent discovery of Semecarpus kathalekanensis, an altogether new evergreen tree species belonging to the mango family Anacardiaceae, from some of the Myristica swamps of Uttara Kannada, highlights the importance of such swamps, as centres of extremely threatened endemic biodiversity of Western Ghats.
The Myristica swamps are usually enmeshed amidst the least disturbed patches of evergreen forests, which outlived to some degree the all pervasive human impacts through the last few millennia. Apart from the species mentioned already the micro-heterogeneity of these relic forests has several more endemic and interesting plant species such as Cyathea nilgirica. (tree ferns), Dipterocarpus indicus, Mastixia arborea, Myristica malabarica, Pinanga dicksonii, Piper hookerii etc. Some such forest relics of southern Uttara Kannada form the northernmost limit for the distribution of the endangered Lion-tailed Macaque, a primate endemic to the southern Western Ghats. The Myristica swamps form important watershed forests and act as feeders for perennial streams.
The Myristica swamps today occur in isolated patches; the southernmost swamps are found in Travancore and the northernmost occur in Goa. All over the low and medium altitudes (<1500 m) of South Indian Western Ghats, over the last several centuries, because of ever increasing human impacts most of the primeval evergreen forests have given way to secondary forests, cultivations, savannas, monoculture tree plantations, commercial plantations of tea, coffee, rubber etc., rice fields, arecanut gardens, mining areas etc.
Amidst the highly human impacted landscapes of Western Ghats are small stretches of relic primeval forests. These forests escaped human impacts to certain extent because of their sacred nature, their watershed and biodiversity values (as the sources of mainly pepper and spices) or due to their inaccessibility.
Chandran and Mesta (2001) consider Myristica swamps as priceless possessions for evolutionary biology. The swamp, with its entanglement of aerial roots, and canopy of dark green large leaves, and high degree of endemism, is doubtlessly, the relic of one of the most primeval ecosystems of the Western Ghats. As much remained undone regarding the diversity and ecology of these swamps, they were considered “virtually live museum of ancient life of great interest to biologists” (ibid.).
With this presumption, that the Myristica swamps and their immediate surroundings, studded with Dipterocarpus trees, could shed some light on the nature of the primeval low altitude evergreen forests of the South Indian Western Ghats, we began surveying these forest relics more systematically. Our search resulted in the find of two very significant tree species viz. Madhuca bourdillonii (Gamble) Lam. and Syzygium travancorica (Gamble). We consider the discovery of these two tree species in Uttara Kannada district at (14 degrees north lat.) as very significant due to the following reasons:

  • The above species were originally reported from Travancore Western Ghats only

  • These species were feared to be extinct according to the Red Data Book of Indian Plants (Nayar and Sastry, 1997, 1988). Subsequent investigations revealed their rare presence in southern Western Ghats (Sasidharan & Sivarajan 1996; Sasidharan 1997).

  • The Myristica swamps near which we found these species had the status of kan forests. The kans were, during the pre-colonial times, safety forests cum sacred groves (Chandran & Gadgil, 1993).

Madhuca bourdillonii (Gamble) Lam.
Bourdillon (1908), the discoverer of this species in Travancore during 1894-95 described it as a “rare tree of medium size occurring in the Ariankavu and Shendurni valleys, but not seen elsewhere”. Gamble (1935), quoting Bourdillon, described it in his Flora of the Presidency of Madras (vol.2). As the species was not collected since Bourdillon’s observation in 1894-95 the Red Data Book of Indian Plants considered its status as “possibly extinct”. It states: “Indiscriminate and steady destruction of its natural habitats, compounded by selective felling of Madhuca trees in the past for their purported all round value, accounts for the present day state of scarcity in the Western Ghats region” Nayar & Sastry (1988).
The rediscovery: Sasidharan and Sivarajan (1996) found this species in the forests of Thrissur district, to the north of the type localities. Later, Saisdharan (1997) found the tree also in its type localities Arainkavu and Shendurni Valley, where it was reported as “rare”.
Occurrence of M. bourdillonii in Uttara Kannada: Notably all the findings of the species hitherto were in the Western Ghats south of the Palghat Gap. We found a rare population in the Ankola taluk of Uttara Kannada district in the Karnataka Western Ghats. Our find extends the northern limit of the species by 600 km; but more significantly, this is the first report of the species from north of the Palghat Gap. There were just 13 trees of this critically endangered species dispersed within a stretch of semi-evergreen forests of Ankola taluk (Lat….Long….). Three of them somewhat exceeded 30 m in height and were about 2 m in girth. Others were of smaller dimensions. The trees occured in the vicinity of a Myristica swamp, which is distinguished by the swamp- exclusive Myristicaceae tree, Gymnacranthera canarica. The swamp occurs in what is apparently a relic forest (see Plate-1), characterized by Western Ghat endemics such as Aglaia anamallayana, Dipterocarpus indicus, Garcinia talbotii, Holigarna spp., Knema attenuata, Myristica malabarica etc. Incidentally the site is also a northward extension for Dipeterocarpus indicus by about 50 km.
Description: M. bourdillonii is a medium to large evergreen tree exceeding 30 m height at maturity (Plate- 2). Though described as an evergreen (Nayar and Sastry, 1980), it has a brief period of leaf-fall, which is not strictly season bound. The leaf-fall may vary from tree to tree. Flowering is simultaneous with leaf fall and new flush that follows is mingled with late blooming flowers and early fruits.
The trees have grayish brown, longitudinally fissured and flaky bark with a pinkish interior. The plant parts have milky latex like other species of Madhuca. Young shoots, including young leaves, are densely covered with brownish-orange, wooly hairs. In the older leaves the undersurface of veins retains the hairs. Mature leaves, at least, are not hairy in other related species like M. longifolia var. longifolia and M. longifolia var. latifolia and M. neriifolia.
The leaves which attain dimensions of 22 x 6.5 cm are simple and crowded towards the tips of branchlets. They have conical base and bluntly acute to somewhat narrowing tips. In having 20-25 pairs of lateral nerves M. bourdillonii stands apart from its close associates M. longifolia var. longifolia (10-12 pairs) and M. longifolia var. latifolia (10-14 pairs).
Flowers appear in dense clusters from the axils of fallen leaves or of older leaves that are about to fall. While the tree is in full bloom clusters of young leaves appear from the tips of branchlets. The stalks of flowers, 1.5-2 cm long, are also covered with dense hairs. The 4 ovate sepals are hairy outside. The 12 petals of the corolla are united towards the base. Stamens, often twice the number of petals, occur in two whorls, inner to the corolla. The anther is tipped with a narrow outgrowth.
Madhuca spp. produce berries with one to few seeds. Globose fruit is a key distinguishing character of M. bourdillonii. M. longifolia var. latifolia has somewhat globose fruit but with oblique apex (Saldanha, 1984) and M. longifolia var. longifolia has ovoid fruit. It has only 1 or 2 seeds whereas M. bourdillonii has 2-3 seeds

(see Table-1 for comparison of the various Madhuca spp. of South India)

Table 1: Comparative morphology of different species of Madhuca


M. bourdillonii

M. longifolia var. longifolia

M. longifolia

var. latifolia

M. neeriifolia

M. insignis

Tree height

Large (>25 m)

Large (>25 m)

Large (>25 m)

Small (8-10 m)



Grayish brown, fissured & flaky

Dark brown, scaly

Dark, fissured and scaly

Dark, scaly


Leaf shedding





Evergreen (?)

Leaf size (cm)

20-30 x 6 -10

5.5 -12 x 1.5-4

7-22 x 5-14

7-24 x 3-6

9-13 x 4-6

Leaf hairiness (mature leaf)

Petioles & underside of veins with brownish-orange, wooly hairs





No. of lateral nerves (pairs)




14 -25








Fruit shape



Globose often with oblique apex

Fusiform, beaked


Surface of mature fruit






No. of seeds






Syzygium travancoricum Gamble

The tree was first discovered in the swampy lowlands (altitude <65 m) of Travancore by Bourdillon in 1894. Gamble described it in 1918 in the Kew Bulletin and in the Flora of the Presidency of Madras in 1919. The Red Data Book of Indian Plants, vol-1 (Ed. Nayar and Sastry, 1987), quoting Nair and Mohanan (1981), states: “Apparently no tree is surviving in the type locality. Recently only 4 trees have been spotted in a sacred grove of Aikad in Quilon district.” Sasidharan’s (1997) collection of the species from the Shenduruny Wildlife Sanctuary shows that the species has not become extinct in the type locality. According to him this species, endemic to Southern Western Ghats of Kerala, is “fairly common in the Myristica swamp forests”.

Occurrence in Uttara Kannada: We came across small population of about 35 trees of this endangered species associated with some of the Myristica swamps of Siddapur taluk (Lat… Long…). It occurred in association with several other Western Ghat endemics such as Aglaia anamallayana, Calophyllum apetalum, Diospyros paniculata, D. pruriens, Dipterocarpus indicus, Gymnocranthera canarica, Holigarna grahamii, Hydnocarpus pentandra, Hopea ponga, Mastixia arborea, Myristica fatua var. magnifica, Pinanga dicksonii etc. . In the Ankola taluk a lone tree was observed in a Myristica swamp. Some bushy forms, obviously coppice shoots, occurred close to the lonely tree.
Description: Gamble described the species as “medium sized or large tree”. Sasidharan (1997) described it as “small trees”. Some of the Siddapur trees that we observed attained about 30 m height. The two largest of the trees had girths of 253 and 254 cm respectively. The older trees are buttressed at the base. The young branchlets are 4-angled; in the saplings the angles are winged. The trees in the stream have floating water roots, an adaptation to swampy habitat.
Leaves are simple, opposite, ovate and bluntly acute towards the tip. The leaf base is shortly deccurrent (continued) on the 2 cm long petiole. Leaf measures to 9-18 cm in length and 6-9 cm in breadth. It produces from the midrib 12-15 pairs of lateral nerves.
Flowers occur in the axils of leaves in corymbose cymes of 5-8 cm long. They are very small, 3 mm across. The white petals form a calyptra (cap) in the bud enclosing the stamens. Fruits 0.7 to 1 cm across, purplish to maroon-red, are 1-seeded. Fruits ripen in May-June. The description of the fruit is wanting in any of the floras although fruits are sketched in Sasidharan (1997).

The value of forest patches

Efforts to conserve tropical biological diversity have usually concentrated on setting aside large tracts of forest in national parks and other protected areas. While highlighting the essentiality of such large, relatively undisturbed forests for effective conservation of tropical ecosystems and many forest species, it needs to be admitted that only 5.9% of the world’s land area is in designated protected areas (WRI, 1994). Because of social, economic and political constraints, there is often little hope of expanding protected area systems. A conservation strategy focusing only on large, protected areas will leave the conservation needs of some organisms and habitats unmet; the conservation efforts in the tropics must include areas that lie outside large reserves (Schelhas and Greenberg, 1996).

‘Forest patches’ include a diversity of habitats which are in close proximity forming a mosaic, or even in isolation like a sacred grove in the middle of a village or small town. Investigations into the ecological history of the Western Ghats reveal that the forests here, especially of lower altitudes below 1000 m, constitute a mosaic of patches of varied nature and ages. In the Uttara Kannada district of central Western Ghats, where we conducted our present study, this landscape mosaic, according to traditional pre and early colonial land use typically consisted of sacred forests (kans or devarabana), ordinary forests (kadu or adavi), shifting cultivation areas (kumri or hakkalu), leaf manure forests (betta), grazing lands (bena) etc. in addition to lands under permanent agriculture and horticulture. Such traditional mosaic contained within it streams, ponds, waterfalls and rivers, gorges and steeps and rocky pinnacles, each with its own characteristic species composition (Chandran, 1997, 1998; Chandran and Gadgil, 1993, 1998).
Shifting cultivation was a major enterprise carried out by forest dwelling tribals, throughout the Western Ghats, sparing only the higher altitudes. Carried out through centuries, the primary evergreen- semi-evergreen forests would have been altered substantially. In most sparsely populated interior places of South Indian Western Ghats (Uttara Kannada southwards), as the fallow period was long (sometimes the tribes never returned to the original areas) the forests would re-grow and through time get back most of the original elements of the flora, barring few. As fire was an important factor in shifting cultivation, it may be that hygrophilous endemic tree species such as Dipterocarpus and Vateria indica, failed to regenerate on slash and burn areas.

Forest history of Uttara Kannada district in central Western Ghats (750558and 740513 East longitude and 135526and 153123 North latitude) points out that slash and burn cultivation (known as kumri) in the district could have been as old as three millennia. Gradual progress of shifting cultivation through centuries have altered the primary forests patch by patch, creating vast stretches of secondary forests. In the absence of fires these secondary forests would, through vegetational succession, get back most of their original elements. Yet some key Western Ghat tree species do not easily recolonise the secondary forests. These include Dipterocarpus indicus and Vateria indica. The early agricultural communities, however, left behind a great legacy of sacred groves, known as kan forests in Uttara Kannada and other adjoining districts. The investigations of the kans reveal that many of them are relics of the primary forests of the Western Ghats and are often centers of endemism for both plants and animals. Many of the Myristica swamps are associated with these sacred groves of pre-colonial times (Chandran and Gadgil, 1993; Chandran, 1988; Chandran, 1997; Chandran and Mesta, 2001).

The relic forests, which sheltered the original biodiversity of the Western Ghats suffered severely, over the last 150 years, due to their merger with the state reserved forests and commercial exploitation of forests for timber, monoculture, extension of cultivation etc and numerous other kinds of human impacts.

In the course of our ongoing ecological studies in Uttara Kannada we gave greater importance to the floristic composition of the relic evergreen forests. In some such forests we have come across the rare occurrence of the tree species Madhuca bourdillonii and Syzygium travancoricum. We present here the details regarding these two critically endangered evergreen and endemic tree species of the Western Ghats, which were once considered to be extinct from Travancore, the only region

Habitat fragmentation is one of the key threats to global diversity. The impact of fragmentation is expected to be severe in the tropics, where biodiversity is rich, and human populations are rapidly growing (Cunnigham and Duncan, 2001). Deforestation is occurring at an alarming rate in the tropical lowlands. In many tropical regions, rain forest is restricted to small (<100 ha), isolated fragments. While only the preservation of large areas of tropical forest can safeguard the complete biota, there is growing evidence to support the view that a substantial number of forest species can persist for decades in fragmented forest. Inevitably, small fragments will become the last refuges of many rainforest species that are on the brink of extinction (Turner and Corlett, 1996).

Several authors consider that the current discontinuity of some faunal species in India, might represent relicts of a former continuous distribution (Mani, 1974; Ali, 1935, 37; Daniel, 2002; Das, 2002). Climatic change and deforestation might be the major causes for discontinuous distribution of species that probably existed once in continuous range. In the case of the Lion-tailed macaque (Macaca silenus), endangered primate endemic to the South Indian Western Ghats, Karanth (2003) considers its present day disjunct distribution and aggregation in the relics of wet forest patches, as the result of climatic aridity and deforestation.

The recordings of Dipterocarpus indicus in Ankola taluk further substantiate the findings of Caratini and his co-workers (1991). They had reported the presence of Dipterocarp pollens in the marine core close to Kali River estuary indicating its more northern range of distribution in the past. So far it has been recorded of its distribution up to Sharavathi Valley, the southern region of Uttara Kannada (Karikan and Gersoppa Ghats including Malemane and Kathalekan). This report records its extension to further north of Uttara Kannada.

The lower altitudes of pre-historical Western Ghats, before the beginnings of shifting cultivation, around 3000 years ago, would have been covered with pristine ecosystems, more or less untrammeled by man, except by hunter-gatherers, who seldom if at all, indulged in forest alterations. Especially due to the heavy rainfall, western facing portions of the mountains would have been covered with tropical evergreen to semi-evergreen forests, laced with water courses and swamps (Chandran, 1997).

This was probably true of Uttara Kannada district in the central Western Ghats. Pollen analysis by Caratini et al. from a marine core taken off the coast (1991), reveals that, Dipterocarpus, an endemic tree of the South Indian Western Ghats could have had its northern limits extending at least upto Karwar ( ). Presently Dipterocarpus (indicus), part of the climax evergreen forests of the Western Ghats, is rare in the district, being confined to isolated patches only towards the southern parts. Therefore our discovery of a small patch of Dipterocarpus at ---- lat. In the Ankola taluk of the district is significant. This patch is in the vicinity of a sacred grove of the forest dwelling Karivokkaliga peasants. It is associated with the remains of a Myristica swamp, also relic of a primeval forest. The association of a few trees of Madhuca bourdilloni, far away from its hitherto known locality south of the Palghat gap, over 700 km to the south, clearly goes to prove that this particular forest patch is a relic of a continuous stretch of low altitude evergreen forests along the Western Ghats, at least upto the latitude of Uttara kannda district.
Same could be stated about Syzygium travancorica, a stately tree, thought to be extinct once from Travancore Western Ghats, but rediscovered later, ut only in the stretch of Western Ghats south of the Palghat Gap. Our find of this extremely rare tree, in the Siddapur taluk of Uttara Kannada in the Central Western Ghats is equally significant. These trees are found in a forest of ancient antiquity, dominated by Dipterocarpus and remnants of Myristica swamps. The same stretch of Siddapur forests are also home to the recently discovered new species Semecarpus kathalekanensis.
What we wish to emphasize all along is that in the pre-historical days, before the advances of the slash and burn cultivators, into the lower altitudes of the Western Ghats, may be around 3000 years ago, primeval evergreen forests would have covered most of the hills and valleys, receiving annual rainfall exceeding 2000 mm. Sluggishly flowing streams, characterized by swamps of wild nutmegs (Myristicaceae members), would have formed a network through these primeval forests. These forests would have been characterized by the presence of endemic evergreen tree species such as Dipterocarpus indicus, Gymnacranthera canarica, Madhuca bourdilloni Myristica fatua var. magnifica, Syzygium travancoricum, Vateria indica, etc., with a lot many of others. The ones named here, however, belong to a rare lot, characterized by their near absence in secondary forests of central Western Ghats. Most of these secondary forests owe their origin to the fires set on in the past by the shifting cultivators.
During late October of 2005 one mature tree was leafless another with fully developed young leaves. A third tree was leafless and with full of bunches of flower buds. The flowers opened during November. All the fallen flowers and even the young buds were seen infected with insect larvae.
The heavy immature fruit fall and the infection of flowers with insect larvae seems to be a major obstacle in the fruit setting and in turn the regeneration of M. bourdillonii. Anyhow recently we have observed few seedlings (3 one year old seedlings and 16 young seedlings with cotyledons) under the only tree, which had matured fruits in the last season. This indicates that out of 13 trees (known population) only one tree is producing the viable seeds.
Number of studies reveal depressed reproductive outputs in small and fragmented populations; some species might, on the other hand, might produce more fruits (Turner and Corlett, 1996).


Ali, S. 1935. The ornithology of Travancore and Cochin. Journal ofBombay Natural History Society 37, 814-843.

Bourdillon, T. F., The Forest Trees of Travancore, The Travancore Government Press, Trivandrum,1908, pp 238-239.
Chandran, M.D.S. 1997. On the ecological history of the Western Ghats, Current Science, 73(2), 146-155.
Chandran, M.D.S. 1998. Shifting cultivation, sacred groves and conflicts in colonial forest policy in the Western Ghats. In: Grove, R.H., Damodaran, V. & Sangwan, S. (eds) Nature and the Orient: The Environmental History of South and Southeast Asia. Oxford University Press, Delhi, pp. 674-707.
Chandran, M.D.S. and Gadgil, M. 1993. Kans- safety forests of Uttara Kannada. In: Brandl, M. (ed) Proceedings of the IUFRO Forest History Group Meeting on Peasant Forestry, 2-5 September 1991. No. 40, Forstliche Versuchs-und Forschungsanstalt, Freiburg, pp. 49-57.
Chandran, M.D.S. and Gadgil, M., 1998. Sacred groves and sacred trees of Uttara Kannada. In: Saraswati, B. (ed) Lifestyle and Ecology. Indira Gandhi National Centre for the Arts & D.K. Printworld, New Delhi, pp 85-138.
Cooke, T., Flora of the Presidency of Bombay, Tailor and Francis, London, 1908.
Cunningham, S.A. and Duncan, D.H. 2001. Plant reproduction in a fragmented landscape. In: Ganeshaiah, K.N. and Shaanker, R.U. and Bawa, K.S (eds) Proc. of the International Conference on Tropical Ecosystems. Oxford & IBH, New Delhi, pp.93-96.
Daniel, J.C. 2002. The Book of Indian Reptiles and Amphibians. Oxford University Press, Mumbai, p. 248.
Das, I. 2002. An Introduction to the Amphibians and Reptiles of Tropical Asia. Natural History Publications (Borneo),Kota Kinabalu, p. 207.
Gamble, J. S., Flora of the Presidency of Madras, Adlard & Son, Ltd., London, Vol 1, 1935.
Karanth, K.P. 2003. Evolution of disjunct distributions among wet zone species of the Indian subcontinent : testing various hypotheses using a phylogenetic approach. Current Science 85(9), 1276-1283.
Mani, M.S. 1974. Biogeographical evolution in India. In: Mani, M.S. (ed) Ecological Biogeography of India. Dr. W.S. Junk B.V. Publishers, The Hague, pp. 698-724.
Rao, R. R. and Razi, B. A., A synoptic Flora of Mysore District, Today and Tomorrows Printers and Publishers, New Delhi, 1981.
Saldanha, C. J., Flora of Karnataka, Vol. 1, Oxford and IBH Publishing Co., New Delhi. 1984.
Nayar, M. P. & Sastry, A. R. K. Red data book of Indian Plants, Vol. I & III, Botanical Survey of India, Calcutta, 1987, 1988.
Sasidharan, N. and Sivarajan, V. V., Flowering Plants of Thrissur Forests, Scientific Publishers, Jodhpur, 1996, pp.265-266.
Sasidharan, N., Studies on the Flora of Shenduruny Wildlife Sanctuary with Emphesis on Endemic species, 1997, pp 125-126.
Schelhas, J. and Greenberg, R. 1996. Introduction: The value of forest patches. In: Schelhas, J. and Greenberg (eds) Forest Patches in Tropical Landscapes. Island Press, Washington D.C., pp. xv-xxxvi.
Subash Chandran, M. D. and Mesta D. K. On the conservation of the Myristica swamps of the Western Ghats. In Forset Genetic Resources; Status, Threats and Conseravtion Strategies (eds R. Umashankar, K. N. Ganeshaiah and Kamaljit S. Bawa), Oxford & IBH Publishing Co. Pvt. Ltd., New Delhi, 2001, pp 1-19.
Turner, I.M. and Corlett, R.T. 1996. The conservation value of small, isolated fragments of lowland tropical rain forest. Tree 11(8), 330-333.
WRI, 1994. WRI/UNEP/UNDP. 1994. World Resources 1994-95. New York: Oxford University Press.
Neginhal, S. G., Forest Trees of South India, S.G. Neginhal IFS (Retd.), Bangalore, 2004.

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