Common reed

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Code: g7
Latin name: Phragmites communis
Source material: Pollen
Family: Poaceae (Gramineae)
Sub family: Arundinoideae
Tribe: Arundineae
Common names: Common Reed, Reed Grass, Reed

Synonyms: Phragmites australis, P. vulgaris, Arundo phragmites, Arundo vulgaris

Closely related species: Canary grass (Phalaris aquatica


A grass species producing pollen, which may induce hay fever, asthma and conjunctivitis in sensitised individuals.

Allergen Exposure

Geographical distribution

The Common Reed is native to Eurasia and Africa, but is now widespread through much of the world, including the United States, Mexico, the West Indies, Chile, Argentina, and Australia.

Common Reed is a tall, warm-season, bamboo-like, perennial, sod-forming grass. The culms are erect, rigid, smooth, and hollow. They may be nearly 2.5 cm in diameter and from 2 to 4 m tall (occasionally up to 6 m), terminating in a 30 cm-long, densely-flowered, tawny or purplish panicle. The plant has stout, creeping, extensive rhizomes, and often stolons as well. Roots grow down to a depth of about 1 m. The leaf-blades, arising from the culm, are broad, flat, 1.5 to 6 cm long and 1 to 6 cm broad, glabrous, green or glaucous, with the sheaths overlapping.

The flowers develop later than in most other grasses, and blooming often coincides with that of common weeds such as Artemisia, or other members of the Compositae, in the late summer to autumn. The spikelets are 10 to 17 mm long, and the florets are exceeded by the hairs of the rachilla. The seeds ripen from late to mid-autumn. The flowers are hermaphrodite (have both male and female organs) and are pollinated by wind.


The Common Reed grows in marshes, swamps and other wet wastelands, and along streams, lakes, ponds and ditches. It is often weedy and very difficult to eradicate, as the stoloniferous rhizomes may reach 10 m or more in length. But for the same reason, it may be planted to stabilise stream banks.

Reeds are very commonly used for thatching and for making partitions, fences, coarse mats, carrying nets, baskets, rope, sandals, pens, brooms, lattices, and arrows.

The shoots, roots, stems, leaves and seeds have culinary uses, and more recently have been harvested for cellulose. Young reeds provide animal forage and green manure. The leaves, flowers and stems are used medicinally, and in ornamental arrangements.

Unexpected exposure

Reeds may be converted into alcohol (for use as a fuel), fertiliser, rayon, insulation, plaster, cork substitute, upholstery filler, boards and paper. A light-green dye is obtained from the flowers.

Allergen Description

Early studies suggested that Common Reed appeared to contain Group 1, Group 2 and Group 5 allergens (1,2).

The following allergen(s) have been characterised:

Phr a 1, a Group 1 grass allergen, an expansin (2-7).

Phr a 2, a Group 2 grass allergen (1).

Phr a 4, a Group 4 Grass allergen (4).

Phr a 5, a Group 5 Grass allergen (1, 2, 4).

Phr a 12, a profiling (1,4).

Phr a 13, a Group 13 Grass allergen, a polygalacturonase (4, 8).

Potential Cross-reactivity

Extensive cross-reactivity among the different individual species of the genus may be expected, and to a lesser degree among members of the closely related subfamily Bambusoideae (Bamboo, Rice), and the family Poaceae (grasses) (9, 10).

Extensive IgE cross-reactivity has been reported between the allergens of the Pooideae grasses: Meadow grass, Meadow Fescue, Cocksfoot, False Oat, Rye, Velvet, Redtop, Sweet Vernal, Cultivated Rye, Common Reed and Timothy grass (11), but variable degrees of difference are likely to exist depending on the presence of individual panallergens that belong to the various grass allergen families.

Although Common reed pollen contains a Group 1 grass allergen, amino acid sequence identity was demonstrated to be high between the allergen Lol p 1 from Rye grass pollen, and Phl p 1, Hol l 1, Poa p 1 and Pha a 1 (greater than 90%), while Lol p 1 and Group 1 allergens from non-Festuciformes grasses (Bermuda grass, Common reed and Rice pollen) share less than 66% of identical amino acids (7).

An Australian study investigating IgE binding to Pha a 1 from the closely related Canary grass (Phalaris aquatica), Lol p 1 (Rye grass), and Cyn d 1 (Bermuda grass) in the sera of 24 grass-allergic patients found binding to occur in 19 of 24, 18 of 24, and 9 of 24 patients respectively. IgE binding to all three major allergens occurred in 8 of 24 sera. The study concluded that although the N-terminal sequence of Pha a 1 is identical to that of Lol p 1, there may be specific allergenic epitopes exclusive to this allergen that are important for allergenicity in southern Australia. A > 90% amino acid sequence identity was shown between Pha a 1 and that reported for Rye grass allergen Lol p 1, and other Group 1 allergens (12).

Cross-reactivity between Timothy grass pollen Phl p 2 was shown to strongly cross-react with group 2 allergens in Sweet vernal grass, Rye grass, Kentucky Bluegrass, Rye and Wheat pollens, but only weak reactivity was observed in Oat and Common Reed pollen (13).

Natural pollen extracts from Anthoxanthum odoratum (Sweet Vernal grass), Avena sativa (Cultivated Oat), Cynodon dactylon (Bermuda grass), Lolium perenne (Rye grass), Phragmites communis (Common Reed), Poa pratensis (Meadow grass), Secale cereale (Cultivated Rye grass), Triticum sativum (Cultivated Wheat), and Zea mays (Maize or Corn) were characterised regarding their allergen contents by means of specific antibodies and by IgE immunoblot inhibition with recombinant allergens from Phl p 1, Phl p 2, Phl p 5, and Bet v 2, using the sera of 193 European, American, and Asian subjects. Immunologically detectable Group 5 and Group 2 allergens were found in all these species except for Bermuda grass and Maize pollen (1).

Group 1 and Group 5 allergens were shown to be present in Dactylis glomerata (Cocksfoot), Festuca rubra (similar to Meadow Fescue), Phleum pratense (Timothy), Anthoxanthum odoratum (Sweet Vernal), Secale cereale (Cultivated Rye), Zea mays (Maize/Corn), and Common reed pollen. The degree of cross-reactivity of IgE antibodies against Lol p 1 or Lol p 5, and these grasses was demonstrated to be highly variable. Individual sera were not always equally cross-reactive to all pollen species. A high degree of cross-reactivity for Group 1 allergens did not necessarily imply the same for Group 5 (2).

A variable degree of cross-reactivity is possible between Common Reed pollen and other pollens that also contain group 13 grass allergens (14). 

Clinical Experience

IgE mediated reactions

Anecdotal evidence suggests that Common reed pollen can induce asthma, allergic rhinitis and allergic conjunctivitis in sensitised individuals; however, few studies have been reported to date (15).

Common Reed grass is a common aeroallergen in the Western Cape, South Africa (15).

Other reactions

Reed dust exposure in the workplace could provoke respiratory symptoms, possibly due to an irritating effect (16). 

Compiled by Dr Harris Steinman, developer of Allergy Advisor,


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  2. Van Ree R, Driessen MN, Van Leeuwen WA, Stapel SO, Aalberse RC. Variability of crossreactivity of IgE antibodies to group I and V allergens in eight grass pollen species. Clin Exp Allergy 1992;22(6):611-7.
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  6. Matthiesen F, Løwenstein H. Group V allergens in grass pollens. II. Investigation of group V allergens in pollens from 10 grasses. Clin Exp Allergy 1991;21(3):309-20.
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  11. Johansen N, Weber RW, Ipsen H, Barber D, Broge L, Hejl C. Extensive IgE cross-reactivity towards the Pooideae grasses substantiated for a large number of grass-pollen-sensitized subjects. Int Arch Allergy Immunol 2009;150(4):325-34.
  12. Suphioglu C, Singh MB, Simpson RJ, Ward LD, Knox RB. Identification of canary grass (Phalaris aquatica) pollen allergens by immunoblotting: IgE and IgG antibody-binding studies. Allergy 1993;48(4):273-81.
  13. Flicker S, Steinberger P, Norderhaug L, Sperr WR, Majlesi Y, Valent P, Kraft D, Valenta R. Conversion of grass pollen allergen-specific human IgE into a protective IgG1 antibody. Eur J Immunol 2002;32(8):2156-62.
  14. Swoboda I, Grote M, Verdino P, Keller W, Singh MB, De Weerd N, Sperr WR, Valent P, Balic N, Reichelt R, Suck R, Fiebig H, Valenta R, Spitzauer S. Molecular characterization of polygalacturonases as grass pollen-specific marker allergens: expulsion from pollen via submicronic respirable particles. J Immunol 2004;172(10):6490-500.
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As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.