anatomy of P. amarus, P. caroliniensis and P. urinaria were studied. they were were collected from faculties of Science and Engineering, Ubon Ratchathani University.
The results show the presence or absence of hypodermis, and the presence or absence of sclerenchyma in cortex useful for keys construction. Keys to species, descriptions and photographs are provided.

leaf anatomy                                              


stem anatomy 

key to species

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith