Latin name: Tilia cordata
Source material: Pollen
Common names: Basswood, European lime, Small-leaved European linden, Small leaved lime, Small-leaved linden
Tilia is native to England and Wales, the south of Scotland, most of Western Europe except southern Spain, Italy and Greece, and parts of the USA. Fifty species of Tilia occur from the north temperate regions downward; they are widely distributed in Europe, Asia and North America, and are found as far south as Indochina and Mexico. Seven species are found on the North American continent. The European species is often used as a street, park or lawn tree. Tilia cordata is the most common species of Tilia.
Tilia cordata is a common deciduous shade or specimen tree, very symmetrical in shape, pyramidal to oval in outline, densely dark-green and shiny-foliaged in summer. The heart-shaped leaves turn yellow or yellow-green in autumn. The tree grows 20 to 27 m in height, or up to 38 m in optimal conditions. The trunk is reddish-brown and very smooth when young, darkening and developing prominent ridges and deep furrows when older. The leaves are alternately arranged, rounded to triangular-ovate, 3 and 8 cm long and broad, and mostly hairless except for small tufts of brown hair in the leaf vein axils (1).
The small, creamy-yellow, moderately fragrant hermaphrodite flowers are produced in clusters of 5 to 11 and appear around June (in the Northern Hemisphere), on lime-coloured, elongated and curving bracts. Linden pollen extends from May to July. Linden in the USA is thought to be mainly insect-pollinated and is believed to lack allergenic activity for this reason, whereas in Europe, where pollination is considered to occur by wind as well, the pollen is regarded as allergenic.
The fruits are small, round, 6 to 7 mm-long and 4 mm-broad nutlets with a rough surface; initially pale green, they occur in clusters hanging from the pale yellow bracts, maturing in autumn to a light tan colour and persisting into early winter. The nutlets are downy at first, become smooth at maturity, and, unlike T. platyphyllos, are not ribbed.
The tree grows wild in woods and on cliffs, and is also domesticated as an ornamental. Sugar can be made from the sap, and beekeepers regard the flowers as a good source of nectar. In Europe the flowers are dried to make tea. Linden is also the source of jute.
No allergens from this plant have yet been characterised.
Assessment of serum of a 21-year-old individual allergic to Linden tree demonstrated several protein bands, mainly at approximately 50 kDa, but also at approximately 23 and 10 kDa (2).
Cross-reactivity among the different species of the genus could be expected (3). Weak cross-reactivity was reported to exist between Linden tree and London plane tree (Platanus acerifolia) (1).
Linden pollen can cause asthma, allergic rhinitis and allergic conjunctivitis (1-4).
Nasal, ocular, palatine, aural and pharyngeal pruritus, conjunctival hyperaemia, sneezing and night cough have been reported in a 21-year-old female. Symptoms occurred every June and were related to the flowering of a Linden tree near her house. A bronchial provocation test was negative. A skin pick test and a conjunctival provocation test were positive and the IgE antibody level was 27.7 kUA/l (1).
A study assessing the aeroallergen sensitisation in an allergic population in Portugal found that high pollen counts could explain the early sensitisation occurring, even in young children. Linden tree was found to be one of the most representative aeroallergens, resulting in sensitisation in 11.4 % of 557 paediatric (< or = 15 years old) patients. Other aeroallergens were grasses (44.9 %), D. pteronyssinus
(32.5 %), D. farinae
(29.1 %), Olea europea
(27.5 %), Parietaria judaica
(23.4 %), Cat dander (16.1 %), Artemisia vulgaris
(17.6 %), Robinia pseudoacacia
(12.2 %), Platanus acerifolia
(11.4 %), moulds (11.2 %), Plantago lanceolata
(10.6 %), Dog dander (10.4 %), and Pinus radiata
(7.5 %) (5).
Sensitisation to the closely related T. platyphyllos
has been reported among children with respiratory allergy in the Trakya region of Turkey (6).Other reactions
Occupational contact dermatitis with rhinoconjunctivitis due to T. cordata
and colophonium exposure in a cosmetician has been reported (7). Contact urticaria has been reported (8).
Compiled by Dr Harris Steinman, email@example.com.
Wikipedia contributors, ”Tilia cordata”, Wikipedia, The Free Encyclopedia, http://en.wikipedia.org/w/index.php?title=Tilia_cordata&oldid=221489083 (accessed July 17, 2008)
Mur P, Feo Brito F, Lombardero M, Barber D,
Galindo PA, Gomez E, Borja J. Allergy to linden pollen (Tilia cordata).
Yman L. Botanical relations and immuno-logical cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
Lewis WH, Vinay P, Zenger VE. Airborne and allergenic pollen of North America. John Hopkins University Press, Baltimore, USA. 1983;90-96:210
Loureiro G, Rabaca M, Blanco B, Andrade S,
Chieira C, Pereira C. Aeroallergens sensitization in an allergic paediatric population of Cova da Beira, Portugal. Allergol Immunopathol (Madr ) 2005;33(4):192-8
Yazicioglu M, Oner N, Celtik C, Okutan O, Pala O. Sensitization to common allergens, especially pollens, among children with respiratory allergy in the Trakya region of Turkey. Asian Pac J Allergy Immunol 2004;22(4):183-90
Krakowiak A, Krêcisz B, Pas-Wyroślak A, Dudek W, Kieć-Swierzyñska M, Pałczyñski C.
Occupational contact dermatitis with rhinoconjunctivitis due to Tilia cordata and colophonium exposure in a cosmetician. Contact Dermatitis 2004;51(1):34
Picardo M, Rovina R, Cristaudo A,
Cannistraci C, Santucci B. Contact urticaria from Tilia (lime).
Contact Dermatitis 1988;19(1):72-3