Summary
Overall, pollen counts were low during this sampling week. Only grasses in Cape Town and trees in Pretoria approached significance, with fungal spores likely high in Durban (no new data).
Cape Town
During this cool weather period with some rain, grass counts were only just moderate. Low tree pollen levels in the atmosphere included bushwillow (Combretaceae), gum (Myrtaceae), pine (Pinaceae), oak (Quercus sp.) cypress (Cupressaceae) and birch (Betulaceae). Low weeds were represented by mezereum (Thymelaeaceae), ferns (Polypodiaceae), the daisy family (Asteraceae), ice planta (Aizoaceae), erica (Ericaceae), sedges (Cyperaceae) and buckwheat (Polygonaceae). Moulds were low.
Calvinia
This pollen strip was not received in Cape Town so last week’s findings are repeated. Tree, weed, and grass pollen levels were low. Trees detected were mesquite (Prosopis sp.), bushwillow (Combretaceae), the sumac family (Anacardiaceae), karee (Rhus/Searsia sp.), and birch (Betulaceae). Weeds included the daisy family (Asteraceae), spurges (Euphorbiaceae), mezereum (Thymelaeaceae), goosefoot (Chenopodiaceae), the carnation family (Caryophyllaceae), buckwheat (Polygonaceae), and nettles (Urticaceae). Moulds were extremely low.
Johannesburg
All pollen categories (trees, weeds, grasses) were very low, as were fungal spores. The tree pollen types detected were hackberry (Celtis sp.), bushwillow (Combretaceae), cypress (Cupressaceae), mulberry (Moraceae), gum (Myrtaceae), plane (Platanus sp.), yellowwood (Podocarpaceae), oak (Quercus sp.) and elm (Ulmaceae). Weeds included only the daisy family (Asteraceae).
Pretoria
Tree pollen counts approached significance, with all other pollen (weeds, grasses) found at low levels. The trees recorded were acacia (Acacia sp.), birch (Betulaceae), bushwillow (Combretaceae), cypress (Cupressaceae), ash (Fraxinus sp.), mulberry (Moraceae), pine (Pinaceae), oak (Quercus sp.), and elevated counts of gum tree (Myrtaceae). Weed pollen included ragweed (Ambrosia sp.), the daisy family (Asteraceae), sedges (Cyperaceae), spurges (Euphorbiaceae), and plantain (Plantaginaceae). Fungal spores were low.
Bloemfontein
Due to high rainfall, overall low levels of grasses, trees, weeds and mould were seen during this sampling period. Tree pollen included acacia (Acacia sp.), false olive (Buddleja sp.), bushwillow (Combretaceae), cypress (Cupressaceae), jacaranda (Jacaranda sp.), mulberry (Moraceae), olive (Oleaceae) and karee (Rhus/Searsia sp.). The weeds detected were pygmy weed (Crassulaceae), mugwort (Artemisia sp.), the daisy family (Asteraceae), goosefoot (Chenopodiaceae) and plantain (Plantaginaceae).
Kimberley
Grass, trees and weed pollen levels were low at this sampling site. Trees detected were pecan (Carya sp.), bushwillow (Combretaceae), gum (Myrtaceae) and olive (Oleaceae). Weeds were goosefoot (Chenopodiaceae) and mezereum (Thymelaeaceae). Moulds were moderate due to the contribution of ascospores and Cladosporium, an allergenic fungal spore, after rain.
Durban
The pollen strip was damaged in transit, so last week’s findings are repeated. Tree, weed and grass pollen levels were low. Trees detected included mulberry (Moraceae), olive (Oleaceae), cypress (Cupressaceae), pecan (Carya sp.), pine (Pinaceae) and the sumac family (Anacardiaceae). Weeds were the daisy family (Asteraceae), ferns (Polypodiaceae), mezereum (Thymelaeaceae) and mugwort (Artemisia sp.). Moulds were high with spikes for ascospores and the allergenic moulds Epicoccum and Cladosporium.
Gqeberha
Counts for trees, weeds, grasses, and moulds were low. The tree pollen observed included acacia (Acacia sp.), the monkey-puzzle family (Araucariaceae), gum (Myrtaceae) and olive (Oleaceae). Weeds were pigweed (Amaranthus sp.), the daisy family (Asteraceae), sedges (Cyperaceae), and spurges (Euphorbiaceae).
