Cycas revoluta

Source: Wikipedia, the free encyclopedia.
This article is about the cycad sago palm. For the "true sago palm", see Metroxylon sagu.

Japanese sago palm
Cycas revoluta male reproductive cone

Least Concern  (IUCN 3.1)[1]
CITES Appendix II (CITES)[2]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Cycadophyta
Class: Cycadopsida
Order: Cycadales
Family: Cycadaceae
Genus: Cycas
Species:
C. revoluta
Binomial name
Cycas revoluta
Synonyms[3][4]
  • Cycas aurea J.Verschaff.
  • Cycas inermis Oudem.
  • Cycas miquelii Warb.
  • Cycas taitungensis
    C.F. Shen, K.D. Hill, C.H. Tsou & C.J. Chen
  • Epicycas miquelii (Warb.) de Laub.

Cycas revoluta (Sotetsu [Japanese ソテツ], sago palm, king sago, sago cycad, Japanese sago palm) is a

native to southern Japan including the Ryukyu Islands. It is one of several species used for the production of sago
, as well as an ornamental plant. The sago cycad can be distinguished by a thick coat of fibers on its trunk. The sago cycad is sometimes mistakenly thought to be a palm, although the only similarity between the two is that they look similar and both produce seeds.

Names

seed plants. The Latin specific epithet revoluta means "curled back",[5] in reference to the leaves. This is also called kungi (comb) palm in Urdu speaking areas.[6]

Description

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 several times, thus producing multiple heads of leaves.[7]

King sago palm in Humble, Texas.

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.[citation needed]

Roots are called coralloid with an

algal layer to resist the algal invasion.[citation needed
]

As with other cycads, it is

megasporophylls. Pollination can be done naturally by insects
or artificially.

Cultivation and uses

Propagation of Cycas revoluta is either by seed or clonally by removal of basal offsets. It 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.[citation needed]

Plant covered with snow.

Of all the cycads, C. revoluta is the most popular in cultivation. It is seen in almost all

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 tolerant of mild to somewhat cold temperatures, provided the ground is dry. Frost damage can occur at temperatures below −10 °C (14 °F). C. revoluta usually defoliates in winter in this temperate climate, but will usually flush (grow) several new leaves by spring.

This plant has gained the Royal Horticultural Society's Award of Garden Merit[9] (confirmed 2017).[10]

Sago

The

Parkinson's, prostate cancer and fibrolamellar hepatocellular carcinoma.[citation needed
]

Aulacaspis yasumatsui is a scale insect feeding on C. revoluta, and unchecked is able to destroy the plant.[12]

Chemistry

Example of a full-grown tree

The hydro-alcoholic extract of leaves of C. revoluta shows the presence of alkaloids, steroids and tannins while the chloroform extract shows the presence of saponins, tannins and sugars.[13] Leaflets also contain biflavonoids.[14] Estragole is the primary volatile compound emitted from the male and female cones of C. revoluta.[15]

Toxicity

Cycad sago is extremely poisonous to animals (including humans) if ingested. Pets are at particular risk, since they seem to find the plant very palatable.[16] Clinical symptoms of ingestion will develop within 12 hours, and may include vomiting, diarrhea, weakness, seizures, and 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).[17] The ASPCA Animal Poison Control Center estimates a fatality rate of 50 to 75% when ingestion of the sago palm is involved. 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

neurotoxic amino acid, and an unidentified toxin which has been observed to cause hindlimb paralysis in cattle.[19]

Gallery

  • Female reproductive structure
    Female reproductive structure
  • Young leaves
    Young leaves
  • Young leaflets curled back, "revoluta"
    Young leaflets curled back, "revoluta"
  • Seeds
    Seeds
  • Seedling
    Seedling
  • A sixteen-year-old two-branched specimen
    A sixteen-year-old two-branched specimen
  • Seeds and seed leaves MHNT
    Seeds and seed leaves
    MHNT

See also

References

  1. doi:10.2305/IUCN.UK.2010-3.RLTS.T42080A10622557.en
    . Retrieved 12 November 2021.
  2. ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
  3. ^ Plants of the World Online. "Cycas revoluta Thunb". Royal Botanic Gardens. Retrieved 2022-05-22.
  4. PMID 35615129
    .
  5. ISBN 9780521866453
    .
  6. ISBN 9781845337315
    .
  7. ^ Thunberg, Carl Peter. 1782. Verhandelingen uitgegeeven door de hollandse maatschappy der weetenschappen, te Haarlem 20(2): 424, 426–427.
  8. doi:10.1111/j.1469-8137.1981.tb01711.x
  9. ^ "Cycas revoluta". Royal Horticultural Society. Retrieved 14 April 2020.
  10. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 22. Retrieved 24 January 2018.
  11. ^ Lafferty, Jamie (2020-01-07). "How a Plant Saved a Japanese Island". BBC.
  12. ^ Aulacaspis yasumatsui (Hemiptera: Sternorrhyncha: Diaspididae), a Scale Insect Pest of Cycads Recently Introduced into Florida. Forrest W. Howard, Avas Hamon, Michael Mclaughlin, Thomas Weissling and Si-lin Yang, The Florida Entomologist, March 1999, Vol. 82, No. 1, pages 14-27 (article)
  13. ^ Leaves Of Cycas revoluta: Potent Antimicrobial And Antioxidant Agent. Manoj K Mourya, Archana Prakash, Ajay Swami, Gautam K Singh and Abhishek Mathur, World Journal of Science and Technology, 2011, Vol 1, No 10, pages 11-20 (article)
  14. doi:10.1055/s-0029-1240743
  15. doi:10.1007/s10265-006-0019-2
  16. ^ Suspected cycad (Cycas revoluta) intoxication in dogs, Botha CJ, Naude TW, Swan GE, et al.| J S Afr Vet Assoc | 1991
  17. ^ Muller-Esneault, Susan (2009). "Cycas Revoluta: The Sago Palm, or Cycad Toxicity". Critterology.com. Archived from the original on 2012-06-05. Retrieved 2009-05-12.
  18. ^ Selected poisonous plant concerns small animals, Knight MW, Dorman DC | Vet Med | 1997 | 92(3):260-272
  19. ^ Toxicology Brief: Cycad toxicosis in dogs, Hany Youssef| Veterinary Medicine | May 1, 2008 | [1]

External links

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