It was easy to identify this a member of the very distinctive and common (in humid American tropics) black pepper genus, Piper, but it certainly was an unusual species. First, you can see that in this species' leaves several strong veins radiate from the leaf bottom. In the leaves of most plants, including Pipers, there's a single midrib running down the blade's center, and secondary veins branch from that.

The most remarkable feature, however, was the erect flower cluster with its individual tiny flowers on stalks. Not many of the genus Piper's hundreds of species produce stalked flowers. A while back we met the Rough-leaved Pepper, a common Piper species here with typical flower spikes, which you can compare at http://www.backyardnature.net/yucatan/piper-am.htm.

This new Piper with stalked flowers is PIPER YUCATANENSE, occuring from Mexico to Panama.

Above you see a close-up of the stalked flowers. The green, spherical items are the ovaries, which will develop into black-pepper fruits -- peppercorns such as those you buy for grinding in your peppermill. Commercial peppercorns are produced by a different Piper species, however, Piper nigrum, a native of tropical Asia.