Am.  Jour  Pharm. ) 
April,  1884.  J 
Pipitzahoic  Acid  and  Species  of  Perezia. 
187 
Species  found  in  the  United  States. 
1.  Perezia  nana,  Gr.,  PL  Trendler  110,  and  Plant,  Wright,,  i,  125, 
seems  to  be  the  most  frequent,  being  found  in  all  the  collections  made 
in  Southwestern  Texas,  Southern  New  Mexico,  all  parts  of  Arizona 
and  the  adjacent  parts  of  Mexico. 
2.  Perezia  runcinata,  Lag.,  from  Chihuahua  and  Sonora  to  Arizona, 
and  New  Mexico  as  far  east  as  the  Colorado  river  in  Texas,  where  it  is. 
not  rare  on  the  rocky  hills  near  Austin. 
3.  Perezia  Thurberi,  Gr.,  PI.  Thurb.,  Sonora,  Southern  Arizona. 
4.  Perezia  Wrightii,  Gr.,  Plants  Wrightianse, — P.  arizonica,  Gr., 
Flor.  Cal.,  not  rare  from  Southwestern  Texas  and  Southern  Utah 
through  Arizona  to  San  Louis  Potosi  (Schaffner). 
5.  Perezia  Parryii,  Gr.,  Proc.  Am.  Acad.  Sci.  and  Art,  vol.  xv. 
Southern  Arizona. 
6.  Perezia  Wislizeni,  Gr.,  Plant.  Fendl.    Southern  New  Mexico. 
7.  Perezia  microcephala,  Gr.,  Acourtia  microcephala,  D.  C.  Coast  of 
Southern  California  (Santa  Barbara,  Monterey). 
Species  of  Northern  Mexico. 
8.  Perezia  formosa,  Gr.,  P.  turbinata,  Gr.,  PI.  Wright,,  non  Llav. 
et  Lex.  Acourtia  formosa,  Don.  A.  macrocephala  and  Trixis  tur- 
binata, Schultz  Bip.  Leg.  Seemann. 
9.  Perezia  thyrsoidea,  Gr.   Bot,  Mexic.  Bound.  Surv.,  leg.  BerlaixL 
10.  Perezia  Seemannii,  Gr.  PI.  Wright.,  leg.  Seem.  Northwestern. 
11.  Perezia  Coulteri,  Gray.    Proc.  Am.  Acad.  xv.    Leg.  Coult. 
12.  Perezia  patens,  Gr.  Acourtia  formosa  and  Trixis  patens, 
Schultz  Bip. 
13.  Perezia  platyphylla,  Gr.    Fendler,  leg.  Coulter,  Zimapam. 
14.  Perezia  rigida,  PL  Gr.  PL  Wright.  1.  c.  Acourtia  rigida,  D.  O. 
A.  formosa,  Hook,  et  Arn. 
Species  of  Central  Mexico. 
15.  Perezia  adnata,  Gray.  This  is  the  mother  plant  of  the  Raiz  del 
Pipitzahuac  of  the  natives,  brought  first  to  the  notice  of  European  bot- 
anists by  Schaffner,  who  collected  the  plant  near  Tolueca.  Trixis 
Pipitzahuac,  Schaffner  et  Schultz  Bip.,  Dumerilia  Alami,  1).  C.  Pere- 
zia Alami,  Hemsia  Biol,  of  Central  Americ,  Bot,  ii.  Morelia  legit 
Giesbrecht, 
