Black Widow
i think a black widow
The spider you are describing is likely the black widow spider. Black widows are known for their shiny black bodies with a distinctive red hourglass shape on their underside. They can be found in Arizona and are known for their venomous bite.
The spider you are describing is likely a type of spider called a redback spider. Redback spiders are common in Australia and are known for having a distinctive red stripe on their upper abdomen and a black underside. They are venomous and should be avoided.
A black widow spider is black with a red mark on it's abdomen; this might or might not be what you meant. The black widow sometimes has a red mark on her back, as well. The red backed spider of Australia, a relative of the black widow, has an orange red mark on the back.
A RED BACK!!! bY THE WAY I WOULDN'T TOUCH IT!! THEY ARE REALLY DEADLY, ESPECIALLY THE BABY ONES!!! ^ i wouldn't pay attention to that If the red is on the belly then worry more, it the red is on the back its not a black widow, ive seen a bunch of spiders with a black body and white stripe, they are jumping spiders, the red button i don't know much about.
The Red-back spider (Latrodectus hasselti) is commonly found in Australia. They are a small black venomous spider with long thin legs, and the females have a red stripe on their globular abdomen.
The black spider that resembles a black widow without the red hourglass marking is likely the false black widow spider (Steatoda grossa or Steatoda nobilis). They are similar in appearance to black widows but lack the distinctive red hourglass marking. These spiders are not as venomous as black widows but can still deliver a painful bite.
This is probably a Red-Backed Jumping Spider. The male has a black body with a bright red abdomen. The female is the same, but the red abdomen has a black stripe. They're found all over the United States. If you want pictures of them, you can find them online at http://kaweahoaks.com/html/spi_phidippus_johnsoni.html.
The spider you are describing is likely the redback spider, a venomous species found in Australia. They are known for their distinctive red stripe on the back and red markings on their joints. Be cautious around them as their bite can be harmful.
Black Widow
The Two Step Spider, or Jockey Spider, is actually a reference to the Redback Spider which is indigenous to Australia. They look much like a Black Widow with an hourglass underbelly but the females also have a red stripe across the backside. -Joe There is a spider that can turn into a banana but no two step spider.
They are called Postman Butterfly, not sure scientific name