261 
Alisma  lanceolatum  With.  Burwell  Lode,  Cambs. 
v.c.  29,  Sept.  14,  1909. — A.  J.  Crosfield. 
Potamogeton  heterophyllus  Schreb.  (Ref.  No.  1403). 
Without  floating  leaves.  Killarney,  Co.  Kerry,  July,  1907. 
—Coll.  Mrs.  Jenner.  Comm.  E.  S.  Gregory.  This  specimen 
is  near  to  P.  intermedins  Tiselius,  but  is  probably  nearer 
heterophyllus  Schreb.  Dr.  Tiselius  now  calls  his  plant 
nitens,  var.  intermedins,  and  Mr.  Fryer  seems  to  concur 
in  this.  Of  course  your  name  is  what  would  be  generally 
given  to  it,  but  it  is  not  exactly  heterophyllus  in  any  form. 
P.  Zizii  Koch.  Ditch,  Witcham  Medlands,  Cambs., 
v.c.  29,  Sept.  9,  1909. — Coll.  E.  W.  Hunnybun.  Comm. 
S.  H.  Bickham.  Passed  by  Mr.  A.  Bennett. 
P.  varians  Fryer.  Woodwalton  Fen,  Hunts.,  v.c.  31, 
Aug.  27,  1909. — Coll.  E.  W.  Hunnybun.  Comm.  S.  H. 
Bickham.  The  doubt  about  this  plant  being  a  hybrid  in 
America  arises  from  Dr.  Morong’s  remark  that  “  a 
weighty  argument  against  this  view  is  the  fact  that 
neither  of  the  supposed  parents  occurs  in  Mystic  Pond.” 
(Monograph  N.  Am.  Naiad.,  p.  27,  1893).  But  Prof.  M.  L. 
Fernald  in  “  Rhodora  ”  (1906),  p.  224,  remarks  “In  view 
of  Dr.  Morong’s  positive  statement,  therefore,  it  is  import¬ 
ant  to  record  the  fact  that  in  the  Gray  Herbarium  there 
is  a  sheet  of  very  characteristic  P.  angustifolins  (Bercht. 
and  Presl.),  collected  by  the  late  W.  Boott  in  ‘Mystic 
Pond,  Aug.  26’  (presumably  in  the  sixties),  and  that  in 
both  the  Gray  Herbarium,  and  in  that  of  the  New  England 
Botanical  Club  there  are  characteristic  specimens  of  P. 
heterophyllus  collected  in  Mystic  Pond  by  Messrs.  E.  and 
C.  E.  Fascon.  There  is  then  no  reason,  as  maintained  by 
Dr.  Morong,  why  P.  spathaeformis  should  not  have 
originated  by  the  hybridizing  of  P.  angustifolins  and 
P.  heterophyllus  in  Mystic  Pond  as  well  as  in  Cambs., 
England.  To  explain  the  above  it  may  be  well  to  give 
here  the  names  it  has  passed  under.— 
P.  varians  Fryer. 
P.  varians  Morong  in  Herb. 
P.  spathaeformis  Tuckerman  in  Herb. 
P.  gramineus,  var.  (?)  spathulaeformis  Robbins  in 
A.  Gray’s  Man.  Bot.  Northern  U.  States  (1867 
and  1870),  p.  487. 
