Allergy : A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Pollen Calendar

Urticaceae

Urtica incisa
Source: University of Newcastle [ 3 ]

The nettle family of the Urticales order (nettle), consists of aproximately 45 tree (generally small), shrub, herb and a few vine genera. Found mainly in tropical regions. Many species, especially the nettles ( Urtica , the common stinging nettle is Urtica ferox ) and Australian nettle trees ( Laportea ), display stinging hairs on the stems and leaves. Similar to the ragweeds, the small, greenish flowers often form clusters in the leaf axils. It is the curled stamens of the male flowers, which release the pollen responsible for allergic reactions.The long fibres in the stems of some species, such as ramie ( Boehmeria nivea ), are used in the textile industry. One species of Australian nettle tree, Laportea moroides, is cultivated for its raspberry-like flower clusters. Pellitory ( Parietaria ), a genus of this order, are common wall plants and are often grown as ornamentals. Wall pelliory ( Parietaria judaica ) is also responsible for pollen-induced allergic reactions. [ 1 ]



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Elm (Ulmus)

Elm refers to any of about 18 species of forest and ornamental shade trees of the family Ulmaceae , which are native in northern temperate regions. Elm are often cultivated for their attractive foliage. Characterised by their petalless flowers, which appear before the leaves and the nutlike fruit, which is surrounded by a flat, hairy (sometimes), winglike structure called a samara. Species include: the American elm ( U. americana) ; slippery, or red, elm ( U. rubra ); rock, or cork, elm ( U. thomasii ); Chinese elm ( U. parvifolia ); English elm ( U. procera ); Wych elm ( U. glabra ); Camperdown elm ( U. glabra camperdownii ) and the fast-growing Siberian elm ( U. pumila ). Most species are susceptible to the fungoid disease, Dutch elm disease. [ 1 ]

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Mulberry (Moraceae )

Streblus
brunonianus

Source: University of Newcastle [ 3 ]

The Moraceae , or Mulberry, family consists of deciduous or evergreen trees and shrubs, often climbing, generally of pantropical distribution and typified by a milky sap. Many of the Moraceae genera are known for their edible fruit, for example the Morus (mulberry tree), Ficus (fig tree) and Artocarpus ultilis (breadfruit tree). Both the white ( M. alba ) and the red ( M. rubra ) mulberries are cultivated in North America for their fruit, which is soft, juicy and edible - not too unlike the blackberry. The red mulberry is used to make mulberry wine. Silkworms are feed on mulberry leaves. [ 1 ]

 



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Wall Pellitory ( Parietaria judaica )

A wall-climbing plant, common all around the Mediterranean and along the West coast of Europe as far north as central England. The wall pellitory flowers all year round but with distinct peaks in Spring and around November. Surprisingly, no cross reactions are displayed to the closely-related Urticaceae family nor to other species of pellitory. [ 2 ]

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[1] The Encyclopaedia Britannica Online : http://www.britannica.com
[2] European Pollen Information : http://www.ngdc.noaa.gov/paleo/epd/
[3] The Geomorphology and Quaternary Science Research Unit, School of Geosciences, University of Newcastle, Callaghan, NSW, 2083, Australia : http://www.newcastle.edu.au/

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  http://www.hon.ch/Library/Theme/Allergy/Glossary/urticalea.html Last modified: Wed Oct 20 2004