Summary
Tree pollen is now high or moderate at all the inland sites and rising at coastal sites. The allergenic trees: Plane, oak, cypress and olive are at the peak of their pollen release cycle. Mulberry is also high at some sites and Buddleja has begun its flowering cycle. Grasses are low at all sites and weeds are low but more varied.
Cape Town
Tree pollen increases in spring as cypress (Cupressaceae), yellowwood (Podocarpaceae), plane (Platanaceae), oak (Quercus), pine (Pinaceae), olive (Oleaceae), cedar (Cedrus), as (Fraxinus), mulberry (Moraceae), gum (Myrtaceae) and Australian pine (Casuarina) release pollen. Weeds are in low concentrations but more varied and include erica (Ericaceae), protea (Proteaceae), English plantain (Plantaginaceae) sedges (Cyperaceae) nettles (Urticaceae) and mugwort (Artemisia). Moulds are generally low. 4-year means are given.
Johannesburg
Tree concentrations were even higher during this sampling week. The dominant tree pollen types were plane (Platanaceae), cypress (Cupressaceae), African stinkwood (Celtis), mulberry (Moraceae) and oak (Quercus). Lower concentrations were seen for false olive (Buddleja), sweetgum (Liquidamber) and ash (Fraxinus). Low weed concentrations included the carrot family (Apiaceae), erica) Ericaceae), mistletoe (Loranthaceae) and slangbos (Stoebe-type). Grasses and moulds were low.
Pretoria
Spring flowering trees include mulberry (Moraceae), cypress Cupressaceae), plane (Platanaceae), birch (Betulus), African stinkwood (Celtis), Australian pine (Casuarina) ash (Fraxinus), gum (Myrtaceae), poplar (Populaceae) and karee (Rhus/Searsia). Weeds are usually the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and the carnation family (Caryophyllaceae). Moulds are in low concentrations. 4-year means are given.
Bloemfontein
The high tree concentrations continued this week and the flowering trees included birch (Betulus), false olive (Buddleja), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), olive (Oleaceae), plane (Platanaceae), poplar (Populaceae), oak (Quercus) and karee (Rhus/Searsia), Weeds were detected in low concentrations and included the daisy family(Asteraceae), pigmyweeds (Crassulaceae), mallows (Malvaceae) erica (Ericaceae) and ferns (Polypodiaceae). Grasses and moulds were low.
Kimberley
Tree pollen increases in spring to include African stinkwood (Celtis), mulberry (Moraceae), olive (Oleaceae), cypress (Cupressaceae), poplar (Populaceae), pine (Pinaceae) and bushwillow (Combretaceae). Weeds are goosefoot (Chenopodiaceae) and the daisy family (Asteraceae). Moulds are in low concentrations before the rains. 4-year means are given.
Durban
In early spring moulds fluctuate while slight increases in tree and pollen concentrations are seen. Trees include yellowwood, cypress (Cupressaceae), mulberry (Moraceae), (Podocarpaceae), palm (Arecaceae) and birch (Betulus). Weeds are sedges (Cyperaceae), the carnation family (Caryophyllaceae), mugwort (Artemisia), nettles (Urticaceae) and knotweed (Persicaria). Moulds are generally low. 4-year means are given.
Gqeberha:
Some tree pollen concentrations reached moderate levels during this sampling week. Trees identified included pine (Pinaceae), yellowwood (Podocarpaceae), the pea family (Fabaceae), gum (Myrtaceae) and waxberry (Morella). Weeds were mugwort (Artemisia), aloe (Asphodelaceae), the daisy family (Asteraceae), sedges (Cyperaceae), goosefoot (Chenopodiaceae), erica (Ericaceae) and spurges (Euphorbiaceae). Grasses and moulds were low.
Potchefstroom
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George
Tree pollen concentrations began to increase at this coastal site. Moderate concentrations for pine (Pinaceae) and yellowwood) were detected while other tree pollen included pecan (Carya), cypress (Cupressaceae), olive (Oleaceae) and gum (Myrtaceae). Weeds were sedges (Cypress), aloe (Asphodelaceae), the daisy family (Asteraceae), goosefoot (Chenopodiaceae), erica (Ericaceae) and nettle (Urticaceae). Moulds remained low.
Reference Range
Grass: Low: 0-5 Moderate: 6-20 High: 21-200
Trees: Low: 0-15 Moderate: 16-90 High: 91-1500
Weeds: Low: 0-10 Moderate: 10-50 High: 51-500
Moulds: Low: 0-900 Moderate: 900-2500 High 2500-25000
Unit: per cubic metre
