Aconite, Winter Eranthis hyemalis Buttercup
Adder's Tongue (see Lily, Trout/ Dogtooth Violet/ Yellow Adder's-tongue)
Agaric, rooted Xerula furfuracea Gilled Mushrooms
Agaricus, large spored Agaricus macrospora Gilled Mushrooms
Agrimony, hairy Agrimonia griposepala Rose
Agrimony, small-flowered Agrimonia parviflora Rose
Agrocybe, hard Agrocybe dura Gilled Mushrooms
Alcohol inky cap (see Inky cap, common)
Alder, Gray (see Alder, Speckled)
Alder, Snapping (see Witch Hazel, common)
Alder, Speckled Alnus rugosa Birch
Alder, Tag (see Alder, Speckled)
Alexanders (see Angelica/ Alexanders)
Alexanders, golden Zizia aurea Parsley
Alfalfa Medicago sativa Pea
Allspice (see Spicebush, common)
Almond mushroom Agaricus subrufescens Gilled Mushrooms
Alyssum, Sweet Lobularia maritime Mustard
Amanita mold Hypomyces hyalinus Miscellaneous Fungi
Amanita sect. Amanita Amanita sect. Amanita Gilled Mushrooms
Amaranth, Green (see Pigweed, Slender/ Green Amaranth)
Amber jelly roll Excidia recisa Crusts And Slimes
Anemone, Tall (see Thimbleweed/ Tall Anemone)
Anemone, Wood Anemone quinquefolia Buttercup
Angelica/ Alexanders Angelica atropurpurea Parsley
Aniseroot/ Sweet anise Osmorhiza longistylus Parsley
Arbutus, Trailing Epigaea repens Heath
Arrowhead, Broad-leaved/ Duck Potato/ Wapato Sagittaria latifolia Arrowhead/Water Plantain
Arrowwood, Northern/ Toothed Arrowwood Viburnum recognitum Honeysuckle
Arrowwood, Toothed (see Arrowwood, Northern/ Toothed Arrowwood)
Artist's conk Ganoderma applanatum Mushrooms With Pores (Polypores)
Artist's crumblecap Psathyrella delineata Gilled Mushrooms
Artist's fungus (see Artist's conk)
Arum, Arrow/ Tuckahoe Peltandra virginica Arum/Calla
Ash, White Fraxinus americana Olive
Asparagus Asparagus officinalis Lily
Aspen, Big-tooth Populus grandidentata Willow
Aspen, Large Tooth (see Aspen, Big-tooth)
Aspen, Quaking Populus tremuloides Willow
Aspen, Trembling (see Aspen, Quaking)
Aster, bushy Aster dumosus Composite
Aster, Calico Aster lateriflorus Aster-Like
Aster, Crooked-stemmed Aster prenanthoides Aster-Like
Aster, Flat-topped White Aster umbellatus Aster-Like
Aster, Frost-weed/ Heath Aster Aster pilosus Aster-Like
Aster, Heart-leaved Aster cordifolius Aster-Like
Aster, Heath (see Aster, Frost-weed/ Heath Aster)
Aster, Large-leaved Aster macrophyllus Composite
Aster, Late Purple/ Spreading Aster Aster patens Aster-Like
Aster, Lowrie's Aster lowrieanus Aster-Like
Aster, Mountain (see Aster, Whorled Wood)
Aster, New England Aster novae-angliae Aster-Like
Aster, Panicled Aster simplex Aster-Like
Aster, Purple-stemmed Aster puniceus Aster-Like
Aster, Schreber's Aster schreberi Aster-Like
Aster, Sharp-leaved (see Aster, Whorled Wood)
Aster, Small White Aster vimineus Aster-Like
Aster, Spreading (see Aster, Late Purple/ Spreading Aster)
Aster, White Wood Aster divaricatus Aster-Like
Aster, Whorled (see Aster, Whorled Wood)
Aster, Whorled Wood Aster acuminatus Composite
Autumn slime mold Mucilago crustacean Crusts And Slimes
Avens, Rough (see Avens, Rough-fruited/ Rough Avens)
Avens, Rough-fruited/ Rough Avens Geum virginianum Rose
Avens, White Geum canadense Rose
Justicia americana
Amaranthus retroflexus
Amaranthus hybridus
Galanthus nivalis
Sagittaria latifolia
Alisma triviale
Peltandra virginica
Arisaema triphyllum
Symplocarpus foetidus