CROWFOOT FAMILY 91 



Sepals copiously pubescent; lateral lobes of the basal leaves 4-5-toothed. 



22. R. vericundus. 



VIII. Abortivi. 

 Basal leaves, at least some of them, merely crenate. 



Achenes pubescent; heads oblong to cylindrical. 



Petals present; sepals not petaloid. 13. B. micropetalus. 



PetEds wanting; sepals with petaloid margins. 29. B. apetalus. 

 Achenes glabrous, with a minute beak; heads subglobose. 



Basal leaf-blades cordate at the base; plant glabrous. 30. B. abortivus. 

 Basal leaf-blades rarely cordate at the base; plant, especially the stem, with 



spreading hairs. 31. ft. micranthus. 



All the leaves divided or lobed; annuals. 32. B. sceleratus. 



IX. Recobvati. 



Flowers small; petals only 2-5 mm. long; basal leaf-blades divided into 3 rhombic or 

 cimeate-obovate, cleft divisions. 

 Petals 2-3 mm. long. 



Stem glabrous; achenes glabrous. 33. B. Douglasii. 



Stem hairy; achenes usually hirsute when young. 34. JJ. Bongardi. 



Petals 4-5 mm. long; achenes glabrous. 35. B. Earlei. 



Flowers larger; petals 5-12 mm. long; basal leaves often biternately cleft into linear, 

 lanceolate, ovate, or cuneate divisions; achenes glabrous. 

 Pubescence of the stem appressed. 36. B. acHformis. 



Pubescence of the stem spreading. 



Stem low and slender, seldom more than 3 dm. high; petals oblong to oval. 



37. B. occidentalis. 

 Stem tall. 5-10 dm. high; petals broadly obovate. 38. B. montanensts. 



X. Eepentes. 

 Petals less than 1 cm. long. 



Plant glabrous or nearly so. 39. R. oreganus. 



Plant decidedly pubescent. 



Heads of achenes decidedly oblong, about 5 mm. thick. 40. B. pennsylvanicus. 

 Heads of achenes globose, 7-12 mm. thick. 



Plants not stolonjferous; primary segments of the leaves cmieate at the base; 



beak half as long as the body of the achene. 41. B. Macounii. 



Plant producing long lateral branches, rooting at the nodes; primary segments 

 of the lower leaves more or less truncate or subcordate at the base; beak 

 one-third as long as the body of the achene. 42. B. rivularis. 



Petals more than 1 cm. long; stem creeping. 43. B. repens. 



XI. Acres. 

 One species. 44. B. acris. 



XII. Hispid: 

 Petals obovate: divisions of the leaves lanceolate or ovate. 45. R. platyphyllus. 



Petals elliptic; divisions at least of the upper leaves linear. 46. B. orthorhynchus. 



XIII. MULTIFIDI. 



Leaves deeply cordate at the base, their primary divisions lobed or dissected ; style about 

 two-thirds as long as the achene. 

 Achenes callous-margined. 47. B. delphinif alius. 



Achenes marginless. 



Stem glabrous. 48. B. Purshii. 



Stem pubescent. 49. B. Hmosus. 



Leaves truncate or slightly cordate at the base, their primary lobes entire or merely 

 crenate; styles minute. 

 Floating water plants; at least some of the leaves cordate at the base. 



50. B. intertextus. 

 Rooting mud plants; none of the leaves cordate at the base. 51. B. hyperboreus. 



XIV. MtlRICATI. 

 One species. 52. B. arvensis. 



11. COPTIDIUM Beurl. l. C. lapponicum. 



12. BECKWITHIA Jeps. 



Scapel-flowered.bractless; achenes 8-10 mm. long, inflated. 1. B. Andersonii. 



Scape 2-3-flowered, with a leaf-Iikelbract; achenes 3-4 mm. long, not inflated. 



2. B. juniperina. 



13. HALERPESTES Greene. l. H. Cymbalaria. 



14. CYRTORHYNCHA Nutt. 



Sepals spatulate or oblong-ovate, more or less contracted at the base. 



Leaf-segments thick, mostly acute; inflorescence corymbiform. 1. C. ranunculina. 



Leaf-segments thin, broad; inflorescence not corymbiform. 2. C. rupestris. 



Sepals broadly round-ovate, not at all clawed; petals usually wanting. 



3. C. negUcla. 



