Cycas revoluta Thunb.

Common Name: Sago palm
Cycas revoluta is an gymnosperms, belong to the order Cycadales (family Cycadaceae), Its popularly known as sago palm, is not a real palm but a cycad. It is a slow-growing, evergreen, long-lived, medium-sized palm-like plant. It is the most popular species in the genus Cycas. This plant is popularly known as King Sago. It is one of the cheapest and most readily available sources of food starch. It is a native of China and Japan and is widely grown as an ornamental plant in India. In combination with protein from sources such as fish and nuts, and vitamins from wild fruits, it forms a diet that has nourished communities in underdeveloped regions for many centuries. Even today it is a major energy food for many poor populations and is also a valuable famine food in these regions

This attractive, ornamental tree is about 2 m in height and has branched stems with multiple heads. The plants grow in xerophytic areas like exposed slopes and other sunny places where water is scarce. It has a tuberous stem at a young age and rough, thick columnar stem in the adult stage and it is covered with an armour of thick, persistent leaf bases and at the apex with a crown of large compound leaves in apparent whorls. Once or twice a year, they produce a complete circle of new leaves which emerge all at once. The main rachis of the young leaves is in-curled and the leaflets are in-rolled, as in ferns. The general appearance of the plant is similar to that of a small palm and it is popularly known as cocopalm by the natives.

0004 Sago is the edible starch that can be extracted from the stem of cycads. There are two types of leaves: scale leaves and foliage leaves. They are arranged in close spiral succession, alternating with each other. The scale leaves are brown, persistent, more numerous than foliage leaves, and play a protective role. The foliage leaves are large, 60 cm long, compound, and pinnately divided into more than 100 leaflets with a revolving margin, thus giving the plant its species name, Cycas revoluta. The midrib does not have veins and projects beyond the apex, ending in a spine. Petioles are thick and quadrangular in shape.
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There is a taproot system which produces branches and some of the lateral roots become apogeotropic, growing vertically upward on the surface of the ground, where they branch repeatedly and form dichotomously branched coral-like masses, coralloid roots or corallorhiza that are inhabited by blue-green algae, Anabaena cycadacearum. This cyanophycean algae helps the plant to fix atmospheric nitrogen and increases the health and fertility of the soil. The surface of the coralloid roots is beset with lenticel-like apertures, suggesting their respiratory function.

Reference
1. J J Lal (2013) Sago palm. In: Encyclopedia of Food Sciences and Nutrition (Second Edition). Elsevier Science Ltd5035