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. R. micropetalus. 



Petals wanting: sepals with petaloid margins. 29. R. apetalus. 

 Achenes glabrous, with a minute beak; heads subglobose. 



Basal leaf-blades cordate at the base: plant glabrous. 30. R. abortivus. 

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



spreading hairs. 31. R. micranihus. 



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



IX. Recurvati. 



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. R. Doitglasii. 



Stem hairy: achenes usually hirsute when young. 34. R. Bongardi. 



Petals 4-5 mm. long; achenes glabrous. 35. R. 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. R. acriformis. 



Pubescence of the stem spreading. 



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



37. R. occidentalis. 

 Stem tall, 5-10 dm. high; petals broadly obovate. 38. R. montanensis. 



X. Repentes. 



Petals le.5s than 1 cm. long. 



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



Plant decidedly pubescent. 



Heads of achenes decidedly oblong, about 5 mm. tliick. 40. R. pennsyhanicus. 

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



Plants not stoloniferous ; primary segments of the leaves cuneate at the base; 



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



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

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

 one-tliird as long as the body of the achene. 42. R. riviilaris. 



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



XI. Acres. 

 One species. 44. R. acris. 



XII. Hispro: 

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



Petals elliptic; divisions at least of the upper leaves linear. 46. R. orlhorhynchus. 



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. R. delphinifolius. 



Achenes marginless. 



Stem glabrous. 48. R. Purshii. 



Stem pubescent. 49. R. litnosus. 



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. R. intertertus. 

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



XIV. MURICATI. 



One species. 52. R. arvensis. 



11. COPTIDIUM Beurl. l. C. lapponicum. 



12. BECKWITHIA Jeps. 



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



Scape 2-3-flowered, with a leaf-hke bract; achenes 3^ 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. 



Lsaf-segments thick, mostly acute; inflorescence corvmbiform. 1. C. ranunculina. 



Leaf-segments thin, broad; inflorascence not corymbiform. 2. C. rupeslris. 



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



3. C. neglecta. 



