C. revoluta

**Scientific Name:** Cycas revoluta

**Common Name:** Sago Palm / King Sago Palm

**Origin:** Southern Japan

**Distribution and habitat:**

[**To be added]**

**Appearance:**

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 semi-glossy 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.

**Propagation:**

Propagation of 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.

**Cultivation and Uses:**

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.

Of all the cycads, the Sago Palm is the most popular (common) 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 18th century, it is native to various areas of southern Japan and is thus tolerant of mild to somewhat cold temperatures, provided the ground is dry. Frost 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. The cycas 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.

Toxicity:

Cycas Revoluta is extremely poisonous to both humans and animals if ingested. Pets are at particular risk since they seem to find the plant very palatable. Clinical symptoms of ingestion will develop within 12 hours and may include vomiting, diarrhoea, weakness, seizures, liver failure, or hepatotoxicity characterized by icterus, cirrhosis, and ascites. The pet may appear bruised, have nose bleeds (epistaxis), melena (blood in the stool), hematochezia (bloody straining), and hemarthrosis (blood in the joints). The ASPCA Animal Poison Control Center estimates a fatality rate of 50 to 75 percent when ingestion of the Sago Palm is involved. The incidence of Sago Palm ingestion by pets has risen by over 200% in the last five years. If any quantity of the plant is ingested, a poison control center or doctor should be contacted immediately. Effects of ingestion can include permanent internal damage and death.

All parts of the plant are toxic; however, the seeds contain the highest level of the toxin cycasin. Cycasin causes gastrointestinal irritation, and in high enough doses, leads to liver failure. Other toxins include Beta-methylamino L-alanine, a neurotoxic amino acid, and an unidentified toxin which has been observed to cause hindlimb paralysis in cattle.

**Sub-Classes/Forms/Localities:**

There is a sub-class called the Cycas Revoluta Aurea, the so-called "Golden Sago". In this rare sub-class the tips of the pinnae have a golden-yellow colour.

Unlike another variety which flushes gold tipped leaves that subsequently turn brown, this true Cycas Revoluta Aurea flushes with a green set of fronds, the same as the standard Cycas Revoluta. When the leaves become firm, after 6-8 weeks, the tips slowly turn a beautiful golden colour along the edges of the fronds.

This golden colour becomes bolder and brighter as the months pass, this is when the plant looks its very best; much as an autumn foliage plant looks its best in autumn. This harkens the onset of a new flush and the colourful cycle begins all over again.

**Images:**

**1. var. Aurea C. revoluta - leaf tip variagation**

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**2. Uncleaned seed**

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3. Cleaned seed. (Proportioned to regular teaspoon)

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**4.1 Male cone of Cycas Revoluta**

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**4.2 Receptive female cone being pollinated**

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**5. In Garden**

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6. Cycas revoluta seedling a two months after germinating

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To populate this PROJECT thread comprehensively, we are constantly looking for new content to ensure that every aspect of this species is covered in detail for future referencing. Please add your images and details, including leaf detail, seed pictures, cones, etc. Please ensure that the content you are sharing is your own or free for public use. You may be quoted as the source of your original information, so please ensure that it is accurate.

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