Most are.
a black spider
The spider with a black line on its back is commonly known as the black widow spider.
It's most likely the common "Daring jumping spider," Phidippus audax. It's completely harmless.
The spider with black pincers commonly found in your area is likely the black widow spider.
a black widow
Could be the arrowhead spider.
You are probably defining a false black widow.
The spider with two black stripes on its back is commonly known as the zebra spider.
The spider with two black stripes on its body is commonly known as the zebra spider.
I got bit by a spider fitting this description, and hurt very bad. Very small, black spider with two very small dots on its back(side by side), but I don't know what kind it is..left a pretty good welt, and red dot on my leg.
The Black Widow Spider has either a yellow, red, or orange hourglass, but sometimes can look like a dot. Links: http://mysite.verizon.net/vzer75kc/