﻿BUTTERCUP 
  FAMILY 
  85 
  

  

  lobed 
  and 
  cleft 
  into 
  oblong 
  or 
  linear 
  divisions. 
  Flowers 
  about 
  1 
  in. 
  

   in 
  diameter. 
  Petals 
  5-7, 
  yellow, 
  spatulate-oblong 
  or 
  obovate. 
  Akenes 
  

   hardly 
  margined, 
  beak 
  slender, 
  straight 
  or 
  slightly 
  curved. 
  On 
  hill- 
  

   sides 
  or 
  in 
  woods 
  or 
  prairies. 
  

  

  5. 
  R. 
  septentrionalis 
  Poir. 
  MARSH 
  BUTTERCUP. 
  Stems 
  smooth 
  or 
  

   slightly 
  hairy, 
  erect, 
  or 
  in 
  wet 
  ground 
  often 
  forming 
  long 
  runners. 
  

   Leaves 
  3-divided, 
  on 
  long 
  petioles, 
  the 
  divisions 
  stalked, 
  cleft 
  or 
  lobed, 
  

   and 
  wedge-shaped. 
  Petals 
  yellow, 
  obovate, 
  twice 
  as 
  long 
  as 
  the 
  

   sepals. 
  Akenes 
  flat, 
  strongly 
  margined, 
  beak 
  stout 
  and 
  nearly 
  straight. 
  

   In 
  moist 
  soil. 
  

  

  6. 
  R. 
  hispidus 
  Michx. 
  RECLINING 
  BUTTERCUP. 
  Perennial. 
  Stems 
  

   ascending 
  or 
  spreading, 
  densely 
  soft-hairy 
  when 
  young, 
  few-leaved. 
  

   Leaves 
  pinnately 
  3-5-divided, 
  with 
  sharply 
  cleft 
  divisions. 
  Flowers 
  

   5-1 
  1 
  in. 
  in 
  diameter. 
  Petals 
  about 
  twice 
  as 
  long 
  as 
  the 
  spreading 
  

   sepals. 
  Head 
  of 
  fruit 
  globose 
  or 
  nearly 
  so. 
  Akenes 
  broadly 
  oval, 
  

   lens-shaped, 
  with 
  a 
  narrow 
  margin. 
  In 
  dry 
  woods 
  and 
  thickets. 
  

  

  7. 
  R. 
  pennsylvanicus 
  L. 
  f. 
  UPRIGHT 
  BUTTERCUP. 
  Perennial. 
  Stems 
  

   rough-hairy, 
  erect, 
  2-3 
  ft. 
  high. 
  Leaves 
  compound 
  in 
  threes, 
  on 
  long 
  

   and 
  very 
  hairy 
  petioles 
  ; 
  leaflets 
  long-stalked, 
  3-parted, 
  the 
  divisions 
  

   sharply 
  lobed 
  or 
  toothed. 
  Flowers 
  small. 
  Petals 
  yellow, 
  shorter 
  than 
  

   the 
  sepals. 
  Akenes 
  flat, 
  smooth, 
  in 
  oblong 
  heads 
  ; 
  beak 
  broad 
  and 
  

   straight. 
  On 
  low 
  ground.* 
  

  

  8. 
  R. 
  bulbosus 
  L. 
  BULBOUS 
  BUTTERCUP, 
  EARLY 
  BUTTERCUP. 
  

   Stem 
  upright, 
  from 
  a 
  solid 
  bulb 
  about 
  as 
  large 
  as 
  a 
  filbert, 
  about 
  

   1 
  ft. 
  high, 
  hairy. 
  Basal 
  leaves 
  3-divided, 
  the 
  divisions 
  lobed 
  and 
  

   cleft. 
  Peduncles 
  furrowed. 
  Flowers 
  large 
  and 
  showy 
  (|-1 
  in. 
  in 
  

   diameter). 
  Sepals 
  strongly 
  reflexed. 
  Petals 
  roundish, 
  wedge-shaped 
  

   at 
  the 
  base. 
  Akenes 
  with 
  a 
  very 
  short 
  beak. 
  Naturalized 
  from 
  

   Europe. 
  Common 
  in 
  grass 
  fields 
  in 
  New 
  England. 
  

  

  9. 
  R. 
  acris 
  L. 
  TALL 
  BUTTERCUP. 
  Erect, 
  hairy, 
  2-3 
  ft. 
  high. 
  

   Leaves 
  3-7-parted, 
  the 
  divisions 
  of 
  the 
  lower 
  ones 
  wedge-shaped, 
  

   deeply 
  cut 
  and 
  lobed. 
  Peduncles 
  not 
  furrowed. 
  Sepals 
  spreading, 
  

   downy. 
  Petals 
  obovate, 
  a 
  little 
  smaller 
  and 
  paler 
  yellow 
  than 
  in 
  

   No. 
  8. 
  A 
  common 
  weed, 
  naturalized 
  from 
  Europe, 
  in 
  grass 
  fields 
  

   and 
  elsewhere, 
  especially 
  eastward. 
  

  

  II. 
  THALICTRUM 
  L. 
  

  

  Erect 
  perennial 
  herbs. 
  Leaves 
  compound, 
  with 
  stipules. 
  

   Flowers 
  in 
  panicles 
  or 
  racemes, 
  often 
  somewhat 
  monoacious 
  

   or 
  dioecious, 
  wind-fertilized. 
  Sepals 
  4-5, 
  petal-like. 
  Petals 
  

   none. 
  Stamens 
  many. 
  Carpels 
  few 
  or 
  many 
  ; 
  ovule 
  1. 
  Fruit 
  

   a 
  small 
  head 
  of 
  akenes. 
  [The 
  following 
  species 
  are 
  both 
  

   usually 
  dioecious.] 
  

  

  