Exploring species in United States of America
Sedum spathulifolium 
Abbot's Bagworm Moth 
Aberts squirrel 
Aborted entoloma 
Abrupt Epiblema Moth 
Abutilon theophrasti 
Acadian hermit crab 
Acalypha wilkesiana 
Acanthocephala terminalis 
Acarospora fuscata 
Acer circinatum 
Acer platanoides 
Achemon sphinx 
Achlys triphylla 
Acilius mediatus 
Ackee apple 
Acleris cornana 
Acleris fragariana 
Acleris hastiana 
Acleris macdunnoughi 
Acmaeodera tubulus 
Acmon blue 
Acorn Plum Gall Wasp 
Acorn weevil