Conifers are vascular plants of the Class Pinopsida. They are gymnosperms, cone-bearing seed plants whose naked seeds (‘gymnos’ meaning naked, ‘sperma’ meaning seed) stand in contrast to the angiosperms with their enclosed (inside ovaries) seeds and complex reproductive structures (flowers). The Pinopsida were once the dominant plant life of the planet. That was till the rise of the flowering plants or the angiosperms that began to replace their cousins, the gymnosperms, around 100 to 60 million years ago, in the Cretaceous, when the Earth was ruled by the dinosaurs and India was not part of the Eurasian landmass.
The Pinopsida include the likes of Cedrus (Cedar), Cupressus (Cypress), Abies (Fir), Juniperus (Juniper) Larix (Larch), Pinus (Pine), Tsuga (Hemlock), Picea (Spruce) and Taxus (Yew). Most of these genera and their species are found in the cold boreal forests of northern Eurasia and the mountain ranges further south – the Alps, the Carpathians, the Zagros, the Alborz, the Himalayas and the Arakan Yoma to name a few. Conifers do not flourish in the hot lowlands of tropical Asia like they do in regions further north or higher up. And South India happens to be one among those tropical zones. Even the wet and cold peaks of the towering Western Ghats are no exception.
However, they haven’t disappeared completely from the landscape. One of the rare conifer species to retain a foothold in South India is the Karadikkayan or Nirampali (Nageia wallichiana). A member of the genus Nageia it belongs to the family Podocarpaceae. The genus Nageia consists of six species of evergreen trees and shrubs that grow in the tropical and subtropical moist broadleaf forests of South, Southeast and East Asia, and parts of the South Pacific. This is how the IUCN Red List of Threatened Species describes the plant:
This is the most widespread species in the genus Nageia and perhaps also one of the most truly tropical of all conifers, as it occurs near sea level in Dipterocarp forest on the equator. It is scattered but often common in primary rainforest with canopy heights to 50 m or more, and occurs from lowlands to montane forested ridges at 2,100 m a.s.l. In the lowland rainforest it develops a straight bole lifting its crown into the canopy. It is, however, not a long-lived emergent and boles usually are rather slender without buttresses indicating modest longevity. Unlike Agathis (Araucariaceae) it is not gregarious. Kerangas (forest on leached sandy soils) can have both species, as well as other conifers like Dacrydium, Dacrycarpus, Falcatifolium falciforme, and Sundacarpus amarus, mixed with Myrtaceae and other angiosperms that have adapted to poor nutrient situations. In China, N. wallichiana occurs in evergreen subtropical forest dominated by Castanopsis and/or Quercus on hillsides but not in high mountains. In margins of peat swamps, in mossy forest on sandstone plateaus of Sarawak, and on mountain ridges with clay or sand amongst rocks it becomes stunted. In New Guinea it is sometimes associated with Araucaria and Podocarpus in mixed conifer forests, which also have several species of Fagaceae, especially in the genus Castanopsis. Nageia wallichiana is a highly valued timber tree, especially where it grows into tall, straight trees with a long, clear bole. It is traded as podocarp wood. Long timber is sawn into planks for construction (mainly house building); other uses of the wood are plywood, veneer, interior finishing, furniture making, and sometimes (Fly River, Wagu, Papua New Guinea) the construction of small canoes. Small stems are used for household utensils, drumsticks, etc. Leaves are used in Viet Nam as a cure for coughs; decoction of leaves taken orally by the Nicobarese as treatment for painful joints (Pandey et al. 2009). It is not grown in cultivation other than in a few botanic gardens. Logging and forest clearing must have had and still have a negative impact on the total population size of mature trees, but it is virtually impossible to quantify this over such a large and diverse area.
The genus in turn belongs to the podocarp family. The Podocarpaceae flourished across the southern supercontinent of Gondwana (which consisted of South America, Africa, Madagascar, India, Australia and Antarctica). As a result of the breakup of Gondwana, the family achieved a very peculiar distribution with species scattered across the southern landmasses and island chains – Saxegothaea conspicua (Chile, Argentina), Acmopyle sahniana (Fiji), Parasitaxus usta (New Caledonia), Phyllocladus alpinus (New Zealand), Pherosphaera hookeriana (Tasmania), Dacrycarpus expansus (New Guinea), Dacrydium gibbsiae (Borneo) and Afrocarpus falcatus (South Africa, Swaziland, Mozambique, Malawi). The genus Podocarpus on the other hand has attained a range covering this entire expanse with as many as 100 species. The Karadikkayan is a reminder of that distant epoch.
Image Attribution: The image above, sourced from Wikimedia Commons, shows the glossy leaves and seed cones of the Japanese Nagi Tree (Nageia nagi). The Karadikkayan has similar seed cones and glossy leaves.