Botanical Name : Cycas revoluta
Species: C. revoluta
Habitat : E. Asia – China, Japan. Found mainly on the sea shore in S. Japan. Thickets on hillsides on islands, sparse forests on mainland at elevations of 100 – 500 metres in Fujian, China
Cycas revoluta (sago cycad), is an attractive plant native to southern Japan. Though often known by the common name of king sago palm, or just sago palm, it is not a palm at all, but a cycad.
click & see the pictures.
This very symmetrical plant supports a crown of shiny, dark green leaves on a thick shaggy trunk that is typically about 20 cm (7.9 in) in diameter, sometimes wider. The trunk is very low to subterranean in young plants, but lengthens above ground with age. It can grow into very old specimens with 6–7 m (over 20 feet) of trunk; however, the plant is very slow-growing and requires about 50–100 years to achieve this height. Trunks can branch multiple times, thus producing multiple heads of leaves.
The leaves are a deep semiglossy green and about 50–150 cm (20–59 in) long when the plants are of a reproductive age. They grow out into a feather-like rosette to 1 m (3.3 ft) in diameter. The crowded, stiff, narrow leaflets are 8–18 cm (3.1–7.1 in) long and have strongly recurved or revolute edges. The basal leaflets become more like spines. The petiole or stems of the Sago Cycad are 6–10 cm (2.4–3.9 in) long and have small protective barbs that must be avoided.
Requires a strong loam with sharp sand and good drainage. Succeeds in dry soils. Requires a sunny position. Although it is the hardiest cycad, this species is not fully hardy in Britain but can tolerate occasional lows to about -5°c so long as the crown is protected and so is worthwhile trying outdoors in a sheltered position in the mildest areas of the country. Alternatively, it can be given greenhouse or conservatory protection over the winter and be placed outdoors in the summer. Plants are very slow growing. This plant is often used as a food source in its native range but recent research has shown that it can cause chronic nervous disorders if it is not treated properly. Overall its use is not to be recommended, especially since it is becoming rare in the wild. The plants produce special upward growing roots where nitrogen is produced in symbiosis with algae. Dioecious, male and female plants must be grown if seed is required.
Cycas revoluta is one of the most widely cultivated cycads, grown outdoors in warm temperate and subtropical regions, or under glass in colder areas. It grows best in sandy, well-drained soil, preferably with some organic matter. It needs good drainage or it will rot. It is fairly drought-tolerant and grows well in full sun or outdoor shade, but needs bright light when grown indoors. The leaves can bleach somewhat if moved from indoors to full sun outdoors.
Cycas revoluta is either by seed or by removal of basal offsets. As with other cycads, it is dioecious, with the males bearing cones and the females bearing groups of megasporophylls. Pollination can be done naturally by insects or artificially.
Seed – best sown in a greenhouse as soon as it is ripe, 2cm deep in individual pots which are then sealed in plastic bags to keep them moist until germination takes place. Germinates in 1 – 3 months at 25°c. Pre-soak stored seed for 24 hours in warm water then treat as above. Division of suckers in the spring.
Edible Parts: Seed; Stem.
Seed – raw or cooked. They can be dried and ground into a powder then mixed with brown rice and fermented into ‘date miso’ or ‘sotetsu miso’. Caution is advised, see the notes above on toxicity. The heart or pith of the trunk is sliced and eaten baked or powdered. A toxic principal must first be removed. A starch can be extracted from this pith and is used for making dumplings. It is very sustaining.
You may click see : How Sago starch is extracted from the pith of sago palm stems and make edible.
Medicinal Actions & Uses
Astringent; Cancer; Diuretic; Emmenagogue; Expectorant; Tonic.
The leaves are used in the treatment of cancer and hepatoma. The terminal shoot is astringent and diuretic. The seed is emmenagogue, expectorant and tonic. It is used in the treatment of rheumatism. Substances extracted from the seeds are used to inhibit the growth of malignant tumours.
Of all the cycads, the Sago Palm is the most popular in horticulture. It is seen in almost all botanical gardens, in both temperate and tropical locations. In many areas of the world, it is heavily promoted commercially as a landscape plant. It is also quite popular as a bonsai plant. First described in the late 1700s, it is native to various areas of southern Japan and is thus tolerant of mild to somewhat cold temperatures, provided the ground is dry. Frond damage can occur at temperatures below -10 °C or 15 degrees F and there are several healthy plants that have been grown with little protection as far north as Nashville Tennessee and Newport News Virginia, both are in zone 7b… The cycad revoluta usually defoliates in this temperate climate, but it usually will flush (or grow) several new leaves by April. It does however require hot summers with mean temperatures of 30 to 35 °C (86 to 95 F) for successful growth, making outdoor growing impossible in colder places such as northern Europe or the Northeast US, even where winter temperatures are not too cold. One disadvantage of its domestic use is that it is poisonous to animals and humans. One skin breaking scrape can lead to a hospital visit.
Known Hazards : The plants contain alkaloids of carcinogens and also an amino-acid that causes chronic nervous disorders. Regular consumption of the plant leads to severe health problems and death. This toxic principle can be removed if the food is properly prepared but consumption of the plant still cannot be recommended because its use often means the death of the plant and it is becoming rare in the wild.
Disclaimer:The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.