Flowers  perfect  in  a  whorled  panicle.  Sepals  3.  Petals  3,  involute  in  the
bud,  deciduous.     Stamens  6 -12.     Ovaries  numerous  in  a  simple  whorl.     Style


4.4.6  AL1SMACE.E.       (M'ATKU-I'LANTAIX    FAMILY.)

short.  Achenium  I -seeded,  2-8-keeled  on  the  back.  —  Hoots  fibrous.  Leaves
mostly  oval  or  cordate,  nerved,  shorter  than  the  scape.    Flowers  white.
1.  A.  Plantago,  L.  Leaves  long-petioled,  ovate  or  oblong,  acute,  rounded
or  cordate  at  the  base,  3-9-nerved  ;  panicle  large,  lax,  the  whorled  branches  and
elongated  filiform  pedicels  bracted  at  the  base;  aehenia  ohtuse,  15-20  in  a
whorl.  (A.  trivialis,  and  A.  parviflora,  Pursh.)  —  Ditches  and  margins  of  ponds
in  the  upper  districts,  Georgia,  and  northward.  July  and  Aug.  —  Leaves  2'-4'
long.     Panicle  1  °  -  2°  long.
3.    ECHINODORUS,    Eiehard.
Flower-;  perfect,  mostly  in  whorled  raeemes.  Sepals  3.  Petals  3,  imbricated
in  the  bud,  withering.  Stamens  few  or  numerous.  Ovaries  few  or  many,  im-
hrieated,  funning  ribbed  aehenia  in  fruit,  usually  beaked  with  the  persistent
Style. —  Herbs,  with  petioled  nerved  leaves.     Heads  mostly  bur-like.
1.  E.  parvulus,  Engelm.  Small;  leaves  laneeolate  or  spatnlate,  nio>tly
acute,  finely  nerved  and  somewhat  pinnatelv-vcincd,  commonly  shorter  than  the
single  or  clustered  1  -  6-flowered  scapes;  flowers  mostly  clustered  or  umbelled,
on  long  bracted  pedicels  which  are  recurved  in  fruit,  Stamens  9;  aehenia  few,
shorter  than  the  ovate  sepals,  obovate,  flattened  at  the  sides,  and  surrounded
with  5  prominent  ribs,  beakless.  —  Margins  of  shallow  ponds,  Middle  Florida,
and  westward.  July  and  Aug.  —  Scapes  l'-4'  high.  Aehenia  black  and
shining.
