192  Pipitzahoic  Acid  and  Species  of  Perezia.        {  A%pT'i884arm* 
Perezia  Wrightii,  Gr.  This  is  a  robust  plant  from  1  to  2  feet  in 
height,  with  a  woody  tap  root  on  all  sides  covered  by  a  dense  cushion 
of  long  silky  dark  brown  hairs;  freed  from  these,  it  is  found  more 
or  less  contorted,  over  an  inch  long  and  f  of  an  inch  in  thickness. 
The  transverse  section  shows,  when  examined  under  the  microscope, 
numerous  fibro-vascular  bundles,  separated  by  the  intervening  cor- 
tical substance.  Stem  erect,  simple  below,  corymbosely  branched 
above,  smoothish,  the  lower  part  covered  by  the  leaves  which  are 
membranaceous,  3  to  4  inches  long,  2  to  3  inches  broad,  glabrous, 
strongly  ribbed,  unequally  serrated  and  spinulose  denticulate,  closely 
sessile,  with  an  auriculate  or  cordate  base.  Flowering  heads  numer- 
ous, small,  with  short,  glandular  hairy,  subulately  bracted  pedicels, 
terminating  in  dense  clusters  the  branches  of  the  open,  nearly  naked 
corymb,  containing  8  to  10  flowers.  Involucre  small,  scarcely  exceed- 
ing, in  length,  the  fruit;  the  scales  to  the  number  of  12  to  15,  are 
rather  membranaceous,  greenish,  viscid  puberulent,  the  innermost  oblong 
linear,  the  exterior  shorter,  oblong-ovate.  Akenes  5  ribbed,  somewhat 
fusiform,  bearing  a  pappus  of  copious,  soft,  white,  capillary  bristles. 
The  root  is  of  a  bitterish,  not  disagreeable  taste.  The  alcoholic 
extract  is  of  a  pure  deep  yellow  color;  treated  with  an  excess  of  boil- 
ing water  it  yields  an  abundant  crystalline,  golden  yellow  precipitate 
of  pipitzahoic  acid,  which,  by  the  addition  of  a  dilute  solution  of  caustic 
alkali  shows  the  characteristic  splendid  reaction  already  described. 
From  these  observations  it  is  evident  that  the  roots  of  Perezia  Wrightii 
will  serve  as  a  fit  material  for  the  preparation  of  this  acid  in  larger 
quantities. 
According  to  Prof.  Gray,1  Perezia  runcinata  possesses  thick,  tuberous 
roots  similar  to  those  of  the  dahlia.  Unfortunately  I  could  not  pro- 
cure specimens  of  this  plant,  found  nearest  to  the  limits  of  our  eastern 
North  American  flora.  I  am,  however,  in  hope  to  obtain  them  before 
the  close  of  another  season,  as  well  as  a  sufficient  supply  of  the  roots 
of  Perezia  Wrightii  for  the  preparation  of  larger  quantities  of  this 
highly  interesting  and  peculiar  organic  constituent  of  the  North  Ameri- 
can Perezias,  so  as  to  be  able  to  study'  closer  its  properties,  and  obtain 
some  light  in  regard  to  the  uses  to  wThich  it  might  possibly  be  applied 
to  in  the  laboratory  and  in  the  arts,  as  well  as  to  permit  of  a  closer 
investigation  of  its  value  as  a  remedial  agent. 
Mobile,  December,  1883. 
^ep.  Mexic.  Bound.  Sur.  Botany. 
