Preliminary notes on Justicia (Acanthaceae) in Peru.

L. is the most species-rich genus of Acanthaceae in Peru and is here accepted in its broader traditional circumscription. The present paper marks a preliminary step towards a complete revision of the genus in Peru. Taxonomic notes and full synonymy are provided for 45 species including twenty-one new species, all apparently endemic to Peru: J.R.I.Wood & R.Villanueva, J.R.I.Wood & R.Villanueva, J.R.I.Wood & R.Villanueva, J.R.I.Wood & R.Villanueva, R. Villanueva & J.R.I.Wood, J.R.I.Wood & R.Villanueva, J.R.I.Wood & R.Villanueva, R.Villanueva & J.R.I.Wood, J.R.I.Wood & R. Villanueva, J.R.I.Wood & R.Villanueva, J.R.I.Wood & R.Villanueva, R.Villanueva & J.R.I.Wood, R. Villanueva & J.R.I.Wood, R.Villanueva & J,R.I.Wood, R.Villanueva & J.R.I.Wood, J.R.I.Wood & R.Villanueva, J.R.I.Wood & R. Villanueva, R.Villanueva & J.R.I.Wood, R.Villanueva & J.R.I.Wood, J.R.I.Wood & R.Villanueva and J.R.I.Wood & R.Villanueva. New subspecies, subsp. machupicchuensis J.R.I.Wood & R.Villanueva of J. alpina Lindau and subsp. filisepala J.R.I.Wood & R.Villanueva of are described. The genus Mildbr. is united with , the only species in the genus, Mildbr. being treated as (Mildbr.) R.Villanueva & J.R.I.Wood. Wassh., (Nees) Lindau, (Lindau) Wassh., (Standl. & F.A. Barkley) V.A.W.Graham and (Rusby) Wassh. & J.R.I.Wood are treated as synonyms respectively of Wassh., (Ruiz & Pav.) Vahl, Lindau, Vahl and Ruiz & Pav. Fourteen names are lectotypified. The paper is copiously illustrated with line drawings, photographs and pollen images. Distribution maps supplement the information on ecology and distribution provided for all species discussed.