Perianth  none,  or  composed  of  1  -  3  minute  hypogynous  scales  (squam  u-
Ice).  Anthers  versatile,  2-celled.  Styles  2-3,  with  hairy  or  plumose
stigmas.  Fruit  a  caryopsis  (grain).  Embryo  placed  on  the  outside  and
near  the  base  of  mealy  albumen.  —  Root  fibrous.
Synopsis.
Tribe  I.  ORYZE^l.-  Spikelets  1  flowered,  mostly  imperfect.  Glumes  none.  Paleae  2.
Stamens  1-11.
1.  LEERSIA.     Flowers  perfect,  compressed,  panicled.     Paleae  unequal,  ciliate.
2.  ZIZANIA.     Flowers  monoecious  ;   the  pistillate  and  staminate  ones  in  the  same  panicle.
59.  LUZIOLA.     Flowers  monoecious  ;  the  pistillate  and  staminate  ones  in  separate  panicles

3.  HYDROCHLOA.    Flowers  monoecious  :  the  pistillate  and  staminate  ones  in  separate  spikes.
60.  MOXANTHOCHLOE      Flowers  dioecious,  in  terminal  spikes.
Tribe  II.  A GROSTIDEJE.  —Spikelets  1-flowered,  or  with  the  pedicel  of  a  second
flower  above.  Glumes  2.  Paleae  mostly  2,  the  lower  one  often  awned.  Stamens  1-3.
Spikelets  in  open  or  closely  spiked  panicles.
*  Glumes  united  at  the  base,  strongly  compressed-keeled.
4.  ALOPECURDS.     Lower  palea  awned  on  the  back,  the  upper  wanting.     Flowers  spiked.
46*


5-AG  GRAMINE.E.       (GRASS   FAMLLY.)

*  *  Glumes  distinct,  concave  or  keeled.     Palere  membranaceous.     Grain  free.    Spikelets  in

open  or  contracted  panicles-

5.  SPOROBOLCS.    Flowers  awnless.    Seed  loose  in  the  globose  or  obovoid  pericarp.
6.  VILFA.     Flowers  awuless.     Seed  adhering  to  the  closely  investing  pericarp.
7.  AGROSTIB.     Pales  shorter  than  the  nearly  equal  glumes,  the  lower  uwued  on  the  back,

the  upper  sometimes  wanting.
8.  POLYPOGON.     Palere  much  shorter  than  the  long-awned  glumes,  the  lower  one  truncated

and  toothed.     Stamens  3.    Panicle  spike-like.
T».   CI  XX  A.     Palere  rather  longer  than  the  acute  glumes,  the  lower  one  awned  under  the  apex.
Stamen  1.     Panicle  loose.
