US spider species
The 30 species you are most likely to actually encounter, grouped by whether they matter medically rather than by taxonomy — because that is the question people are really asking.
Medically significant
Widows and recluses. These are the only US spiders whose bites can need medical attention — and even here, serious outcomes are uncommon.
Loxosceles reclusa
The brown recluse is genuinely capable of causing a serious wound, and it is also the single most over-reported spider in North America.
Loxosceles deserta
The desert recluse is the southwest's genuine Loxosceles, and it explains why 'no recluses in California' is a slight overstatement.
Latrodectus hesperus
The western black widow is the widow of the western United States and the one most likely to turn up in a garage or under a barbecue.
Latrodectus mactans
The southern black widow is the classic widow of the eastern and southern United States.
Latrodectus variolus
The northern black widow reaches further north than the other US widows, into New England and the upper midwest.
Latrodectus geometricus
The brown widow is an introduced species now common across the deep south and southern California, and it is displacing black widows in many urban areas.
Can sting, but not dangerous
Capable of a bite that hurts briefly and may leave a welt. No lasting effect and no medical significance.
Cheiracanthium inclusum
The yellow sac spider is the small pale spider that turns up on ceilings and walls at night, and it accounts for a large share of genuine indoor spider bites in North America — not because it is dangerous, but because it wanders over people while they sleep and bites defensively when trapped against skin..
Steatoda grossa
The false widow is the spider that causes most black widow scares indoors.
Dysdera crocata
The woodlouse spider looks alarming — bright orange with oversized fangs — and is one of the more distinctive spiders under a garden stone.
Harmless
The overwhelming majority. Most are useful predators, and several actively hunt the spiders in the first group.
Tigrosa and Hogna species
The wolf spider is the big, fast, hairy spider that runs across the basement floor, and it is the single most common cause of alarmed spider reports in the United States.
Eratigena agrestis
The hobo spider spent two decades on the list of medically significant US spiders and was removed from it.
Eratigena duellica
The giant house spider is the large, fast, long-legged spider that appears in Pacific Northwest homes in autumn, usually running across a carpet at speed or sitting in a bathtub it cannot climb out of.
Agelenopsis species
Grass spiders make the sheet webs that appear all over a lawn on a dewy autumn morning.
Parasteatoda tepidariorum
This is the spider responsible for most cobwebs in most houses.
Pholcus phalangioides
The cellar spider is the subject of the most persistent spider myth in circulation: that it has the most powerful venom of any spider but fangs too short to bite.
Order Opiliones
Harvestmen are not spiders.
Argiope aurantia
The garden spider is the big, dramatic, black-and-yellow orbweaver that appears in gardens and field edges in late summer.
Araneus diadematus
The cross orbweaver is an introduced European spider now common across the northern United States.
Araneus marmoreus
The marbled orbweaver is the bright orange spider that appears in October and gets photographed and posted every autumn under the assumption that it must be dangerous.
Gasteracantha cancriformis
The spiny-backed orbweaver is one of the most distinctive spiders in North America and impossible to confuse with anything else once seen.
Trichonephila clavata
The Joro spider is an introduced East Asian orbweaver that has spread through the southeastern United States since about 2014 and is moving north.
Trichonephila clavipes
The golden silk orbweaver is the huge spider that southern hikers walk face-first into.
Phidippus audax
Jumping spiders are the ones that turn to look at you.
Salticus scenicus
The zebra jumper is the tiny striped spider seen darting about on sunlit walls, fences and window sills.
Dolomedes tenebrosus
The dark fishing spider is the enormous flat spider found on tree trunks, dock pilings and — alarmingly for the householder — occasionally on a bathroom wall.
Pisaurina mira
The nursery web spider is a common grassland hunter that carries its egg sac in its jaws — a habit that separates it immediately from wolf spiders, which drag theirs behind.
Misumena vatia
The goldenrod crab spider sits motionless in a flower head waiting for a bee, and it can slowly change colour between white and yellow over several days to match the flower it is on.
Peucetia viridans
The green lynx spider is a large, bright green ambush hunter of southern shrubs and flower heads.
Aphonopelma hentzi
The Texas brown tarantula is the tarantula of the southern plains, and it is far more docile than its size suggests.
Kukulcania hibernalis
The male southern house spider is the most common false brown recluse in the deep south.