Observations by bodorfamily

Discussion and ID on BugGuide, though doesn't entirely match up with Wikipedia description and distribution. It's possible that Wikipedia has it wrong or that the BugGuide listings of P.pullulus in Florida are of a different species.

3mm body length. These spiders are interesting in that they are social, living communally, unusual in the spider world. They are plentiful along our neighborhood nature trail, easily spotted by their webs.

7mm body length. Females of different species of the genus Hentzia are quite similar in appearance. Aside from the dorsal abdominal markings, one difference is the pattern on the carapace, with a small arrowhead in the middle, earning it a nickname of a "Seminole" Hentzia by Lyn Atherton at BugGuide. Her finds in Pinellas County and ours in Sarasota County are further north than past finds.

3mm body length. Cool-looking spider that is a cleptoparasite, living in the web of a larger spider and eating remnants of prey caught in it. This one was in the web of a Tropical Tent Weaver.
I'm listing this as A.elevatus but am not certain how to tell it apart from A.nephilidae.

4mm body length. One of two females found in a patch of azaleas. The orbs are easy to spot and the spider hides during the day in a curled leaf at the edge of the web. At night they hang in the middle of the web. Two color variants noted, this one with a tan butterfly pattern on its back, the other with a pink one. A male was also found a mile from these, at night, hanging from a thread.