Paspalum has about 400 species. P. notatum is native to southern Brazil, Uruguay, the Chaco region of northern Argentina, and northwestern Paraguay, and is found in most Central and South American countries. It may also be native to the West Indies. It has been introduced as a turf and forage grass into East and West Africa, Australia, Japan, Mexico, and the southern and eastern United States. It is widely cultivated in low-altitude pastures of southwestern Japan and is a popular forage grass on the north coast of New South Wales and on the south coast of Queensland, Australia. One species is especially important in India for growing on barren hills because it is drought-resistant.
Paspalum notatum is a sod-forming, deep-rooted, warm-season perennial grass. It spreads by short, stout, woody runners and by seed. The runners have many large, fibrous roots which form dense, tough sods, even on drought-prone sandy soils. The leaf bases at the terminus of each rhizome usually have a purplish hue. The culms (stems) of P. notatum are ascending, usually ranging from 20 to 75cm tall, and the dark green leaves are 4 to 10mm wide and 6 to 25cm long.
The inflorescences have 2 to several spicate branches 4-12 cm long, and each branch (or raceme) has 2 rows of spikelets, either paired or positioned with one slightly below the other. Flowering is between June and November but may flower throughout the year in various locations. (Bahia grass ripens progressively over the summer in the United States and at no time is all the seed mature.) Besides vegetative spread, some varieties can reproduce asexually by unfertilized yet viable seeds; the sexually reproducing varieties are wind-pollinated. The plant seeds prolifically during the summer. The seed stalks are 30 to 75cm high, usually with 2 (sometimes 3) racemes, each about 6cm long. The seeds - oval, yellowish-green, glossy and 3mm in diameter - are typically dispersed by ruminants.
Pollen of Bahia grass (Paspalum notatum) represents a major cause of type I allergy in diverse geographical areas, particularly in the southeastern coastal plain area of the United States. (Ghobrial 2002 ref.6870 1)
Multiple antigenic components have been detected. (Sweeney 1994 ref.154 54)
Bahia grass pollen contains many proteins but only 4 have allergenic reactivity. Following deglycosylation treatment, Bahia grass allergenic proteins have retained their antigenic reactivity with Bahia-grass-allergic patient sera containing polyclonal IgE antibodies. Four proteins reactive with IgE were detected with estimated molecular weights of 45, 33, 31 and 28 kD, but the 33-kD protein was the most reactive. (Ghobrial 2002 ref.6870 1)
IGE AND IMMUNE:
Hayfever, asthma and allergic conjunctivitis.
16% of of patients with allergic rhinitis in this study were positive to this pollen. (Pumhirun 1997 ref.2256 1)
In a study in Cartagena, Colombia, 28% of 99 subjects with acute asthma were found to be sensitised to Bahia grass. (Caraballo 1998 ref.5244 4)
Thirty-eight subjects were challenged (25 nasal, 13 bronchial) with Bahia grass, Paspalum notatum, pollen extract. A positive Bahia intradermal skin test predicted a positive challenge to Bahia in all (11/11) of the nasal challenges and 75% (6/8) of the bronchial challenges. Specific IgE antibodies to Bahia pollen were detected by conventional RAST (greater than or equal to 2+) in 82% (14/17) of subjects with positive challenges and in 5% (1/20) of subjects with negative challenges. Bahia grass is a significant aeroallergen, which in some subjects can be demonstrated not to cross-react with Timothy grass. (Phillips 1989 ref.5415 6)
Cross-reactivity between Bahia grass and Johnson grass can be expected
An Australian study found an association between Bahia grass and asthma in children, and between Bermuda grass and allergic rhinitis in adults. (Bass 2000 ref.5243 3)
Unknown or Nil
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Allergy Advisor - Zing Solutions
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