Cascabela thevetia (
synonymThevetia peruviana) is a
poisonous plant native throughout
Mexico and in
Central America, and cultivated widely as an ornamental. It is a relative of Nerium oleander, giving it a common name yellow oleander.
Etymology
'Cascabel', 'cascavel' or 'cascabela' is Spanish for a small bell, a snake's rattle or a rattlesnake itself.[3] The allusion may also be to the plant's toxicity comparable to the venom of a rattlesnake. The latin specific name thevetia commemorates
André de Thevet (1516-1590), a French Franciscan priest and explorer, who explored Brazil and Guiana[4] (where the plant is known as chapéu-de-napoleão, ie, Napoleon's hat).
Description
Cascabela thevetia is an evergreen
tropical shrub or small tree. Its leaves are willow-like, linear-lanceolate, and glossy green in color. They are covered in waxy coating to reduce water loss (typical of oleanders). Its stem is green turning silver/gray as it ages.[5] Flowers bloom from summer to fall. The long funnel-shaped sometimes-fragrant yellow (less commonly apricot, sometimes white) flowers are in few-flowered terminal clusters.[5] Its fruit is deep red-black in color encasing a large seed that bears some resemblance to a 'Chinese lucky nut.'[clarification needed]
Its bright yellow flowers are used for religious purposes in India. The tree is native to Mexico and thus direct references to Hindu culture are new.
Toxicity
All parts of the C. thevetia plant are toxic to most vertebrates as they contain
cardiac glycosides. Many cases of intentional and accidental poisoning of humans are known.[6]
In South India and in Sri Lanka swallowing the seeds of Thevetia peruviana[19] (Kaneru කණේරු (Sinhala), Manjal arali (Tamil)) is one of the preferred methods for suicides in villages where they are grown in abundance.[20]
Extracts from C. thevetia are reported to possess antispermatogenic activity in rats.[21]
Cascabela thevetia is cultivated as an
ornamental plant, and planted as large flowering shrub or small
ornamental tree standards in
gardens and parks in temperate climates. In frost prone areas it is container plant, in the winter season brought inside a
greenhouse or as a
house plant. It tolerates most soils and is drought tolerant.[5]
Biological pest control
The plant's toxins have tested in experiments for uses in
biological pest control. T. peruviana seed oil was used to make a 'paint' with antifungal, antibacterial and anti-termite properties.[24]
^Shannon D. Langford & Paul J. Boor (1996). "Oleander toxicity: an examination of human and animal toxic exposures". Toxicology. 109 (1): 1–13.
doi:
10.1016/0300-483X(95)03296-R.
PMID8619248.
^Bose TK, Basu RK, Biswas B, De JN, Majumdar BC, Datta S (1999). "Cardiovascular effects of yellow oleander ingestion". J Indian Med Assoc. 97 (10): 407–410.
PMID10638101.
^Bandara V.; Weinstein S.A.; White J.; Eddleston M. (2010). "A review of the natural history, toxinology, diagnosis and clinical management of Nerium oleander (common oleander) and Thevetia peruviana (yellow oleander) poisoning". Toxicon. 56 (3): 273–281.
doi:
10.1016/j.toxicon.2010.03.026.
PMID20438743.
^M. Eddleston; S. Rajapakse; Rajakanthan, S. Jayalath; L. Sjöström; W. Santharaj; et al. (2000). "Anti-digoxin Fab fragments in cardiotoxicity induced by ingestion of yellow oleander: a randomised controlled trial". Lancet. 355 (9208): 967–972.
doi:
10.1016/S0140-6736(00)90014-X.
PMID10768435.
S2CID2095538.
^Kannan,R (1991). "Koels feeding on the yellow oleander". Blackbuck. 7 (2): 48.
^Krishnan, M (1952). "Koels (Eudynamis scolopaceus) eating the poisonous fruit of the Yellow Oleander". J. Bombay Nat. Hist. Soc. 50 (4): 943–945.
^Raj,PJ Sanjeeva (1963). "Additions to the list of birds eating the fruit of Yellow Oleander (Thevetia neriifolia )". J. Bombay Nat. Hist. Soc. 60 (2): 457–458.
^Raj, P J Sanjeeva (1959). "Birds eating poisonous fruit of Yellow Oleander (Thevetia neriifolia)". J. Bombay Nat. Hist. Soc. 56 (3): 639.
^Neelakantan,KK (1953). "Common Grey Hornbill (Tockus birostris) eating fruits of the Yellow Oleander (Thevetia neriifolia)". J. Bombay Nat. Hist. Soc. 51 (3): 738.
^Rajasingh, Simon G; Rajasingh, Irene V (1970). "Birds and mammals eating the fruits of Yellow Oleander (Thevetia peruviana)". J. Bombay Nat. Hist. Soc. 67 (3): 572–573.