Pollen Chart

Common name	Latin name                 Blooming months                  Pollen color
Maple	Acer spp.	Feb - Apr	light yellow	feral		fair
Manitoba Maple  (Box elder)	Acer negundo	Feb - Apr	light olive	feral		good
Norway maple	Acer platanoides	Apr - May	yellow green, olive	feral		fair
Red Maple	Acer rubrum	Mar - Apr	grey brown	feral
Grey Alder	Alnus incana	Feb - Apr	brownish yellow	feral
American Chestnut	Castanea dentata	May - Jun		mostly ornamental
American Hazel	Corylus americana	Mar - Apr	light green	feral and ornamental		fair/good
Sweet Chestnut	Castanea sativa	May		feral		good
Common Hackberry	Celtis occidentalis	Apr - May		feral
Flowering Quince	Chaenomeles japonica, Chaenomeles lagenaria, Chaenomeles speciosa 'Nivalis', Chaenomeles x superba	Apr - May		feral		good
Hawthorn	Crataegus spp.	Apr - May	yellow brown	feral		fair
White Ash	Fraxinus americana	Apr - May
Honey Locust	Gleditsia triancanthos	May - Jun		feral
American holly	Ilex opaca	Apr - Jun		feral
Walnut	Juglans spp.	Apr - May		cultivated		fair
Tulip-tree	Lirodendron tulipifera	May - Jun		feral and ornamental		good
Crab Apple	Malus spp.	Mar - Jun	light olive	ornamental
Apple	Malus domestica, Malus sylvestris	Apr - May	yellow white	cultivated and ornamental		very good
American Sycamore	Platanus occidentalis	Apr - May	light olive	feral
Plum	Prunus spp.	Apr - May	light grey, grey	ornamental and cultivated
Almond	Prunus amygdalus	Feb	light brown to brown pollen - not considered a good pollen source but bees are the primary pollinator	cultivated mostly in California		fair
Wild Cherry	Prunus avium	Apr - May	yellow brown, light brown	feral		very good
Cherry Plum	Prunus cerasifera		light brown to brown	feral		fair
Sour Cherry	Prunus cerasus	Apr - May	dark yellow	ornamental and cultivated		very good
Peach	Prunus persica	Apr - May	redish yellow	ornamental and cultivated		good
Black Cherry	Prunus serotina	Apr - May		feral		minor
Blackthorn	Prunus spinosa			feral		good
Pear	Pyrus communis	Apr - May	red yellow	ornamental and cultivated		good
Oak	Quercus spp.	May		feral
Oak	Quercus robur, Quercus pedunculata	May	light olive	feral		minor
Black Locust	Robinia pseudoacacia	May - Jun		feral
Blackberry	Rubus spp.	May - Jun	light grey	feral and cultivated		excellant
Raspberry	Rubus idaeus	May - Jun		feral and cultivated		good
Willow	Salix spp.	Feb - Apr	lemon	feral		good
White Willow	Salix alba			feral		good
Goat Willow	Salix caprea	Mar - Apr		feral		very good
Violet Willow	Salix daphnoides	Mar - Apr		feral		very good
Pussy Willow	Salix discolor	Mar - Apr		feral and ornamental
Basket Willow	Salix purpurea	Mar - Apr		feral		very good
Silky leaf osier, Smith's Willow	Salix x smithiana	Apr - May				very good
American mountain ash	Sorbus americana	May-Jun		feral
American Elm	Ulmus americana	Feb - Apr	light grey	feral
Winged Elm	Ulmus alata	Feb - Mar	pale yellow	feral		good
Europea field elm	Ulmus americana			feral		good

This pollen chart was originally by www.beesource.com
and 
http://en.wikipedia.org/wiki/Pollen_source