Latin name: Syagrus romanzoffiana
Source material: Pollen
Synonyms: Arecastrum romanzoffianum, Cocos plumose (previous nomenclature), Syagrus romanzoffianum.
Not to be confused with other commonly grown Palms: Mexican fan palm (Washingtonia robusta), California fan palm (Washingtonia filifera), and the Date palm (Phoenix dactylifera).
Syagrus is a genus of 30 to 42 species of the family Arecaceae (Palms). These are native to South America, with a single species endemic to the Lesser Antilles. The genus is closely related to the Cocos or Coconut genus, and many Syagrus species produce edible seeds similar to the Coconut.
The Queen palm is a graceful, fast-growing Palm, native to Brazil, Paraguay and northern Argentina. It is now often found planted in courtyards, rows or groves in tropical climates all over the world. It is popular because it does not drop litter as Fan and Date palms do.
The Queen palm is an evergreen that can grow to 17 m. The single trunk is exceptionally straight, with a smooth bark banded with dark and light grey. The leaves are graceful and arching, whereas King Palm leaves are rather rigid. The leaves are grey-green in colour, pinnate, and arranged in a whorled pattern. The leaves typically grow 3.3 to 5 m long.
The small flowers are cream to yellow in colour. Succulent, indehiscent, 2.5 cm date-like fruits, green to orange in colour, are produced from summer to early winter.
No allergens from this plant have yet been characterised.
An extensive cross-reactivity among the different individual species of the genus could be expected, as well as to a certain degree among members of the family Arecaceae (1).
Anecdotal evidence suggests that asthma, allergic rhinitis and allergic conjunctivitis, similar to reactions caused by other members of this family, are possible following exposure to pollen from this tree; however, few specific studies have been reported to date.
The objective of a study was to examine aeroallergen sensitisation rates among children of the military in Texas who were undergoing skin testing for rhinitis, and to investigate the timing of atopic development in relation to perennial and seasonal allergens. A total of 345 children underwent testing to a 51-allergen panel. A total of 80.3% had at least 1 positive test result, and the average number of positive test results was 11.4. The most common active allergens were grasses, Alternaria, and Cottonwood. Thirty-two of 51 allergens were positive in 20% or more children. Sixteen percent of the children were skin prick-positive for Queen palm (2).
The daily pollen concentration in the atmosphere of Badajoz, in southwestern Spain, over a 6-year period demonstrated the presence of Arecaceae spp. (3).
Compiled by Dr Harris Steinman, firstname.lastname@example.org.
Yman L. Botanical relations and immuno-logical cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
Calabria CW, Dice J. Aeroallergen sensitization rates in military children with rhinitis symptoms. Ann Allergy Asthma Immunol 2007;99(2):161-9
Silva Palacios I, Tormo Molina R, Nunoz Rodriguez AF. Influence of wind direction on pollen concentration in the atmosphere.
Int J Biometeorol 2000;44(3):128-33