310 
IOWA ACADEMY OF SCIENCE Vor.. XXVIII, 1921 
34. Perianth hard, scalelike, beset with scale- 
like bracts Amaranthaceae 
34. Perianth soft, not scalelike; no scaly bracts 35 
35. 
Stipules sheathing stem above node 
Polygonaceae 
35. 
Stipules not sheathing, or none 
36. Ov. many-seeded; plant spreading on the 
36 
ground 
Caryophyllaceae 
36. Ov. few-several-seeded; plant stiff, erect 
Cistaceae 
36. Ov. 1-seeded 
37 
37. 
Sep. 4; style and stig. 1 
Urticaceae 
37. 
Sep. 5 (3-5) ; stig. 2 (-5) 
Chenopodiace^ 
38. FIs. often with pistils only or stamens only 
39 
38. FIs. perfect, i.e., pist. and stam. both 
47 
39. 
Tendril-bearing herbs 
Cucurbitaceae 
39. 
Submerged aquatic with threadlike Iflts. 
Haloragidaceae 
39. 
Herbs 
40 
39. 
Woody vines 
41 
39. 
Trees and shrubs 
43 
40. Evs. simple, oval; fls. minute 
Euphorbiaceae 
40. Evs. compound 
Araliaceae 
41. 
Sep. and pet. absent when fl. is open 
Vitaceae 
41. 
Sep. and pet. present 
42 
42. Evs. simple, palmately veined 
Menispermaceae 
42. Evs. simple, pinnately veined 
Celastraceae 
42. Evs. of 3 Iflts.; poisonous to touch 
Anacardiaceae 
43. 
Evs. opposite 
Aceraceae 
43. 
Evs. alternate 
44 
44. Evs. simple, entire 
Anacardiaceae 
44. Evs. simple, finely toothed 
Rhamnaceae 
44. Evs. simple, palmately lobed 
Saxifragaceae 
44. Evs. of 3 Iflts. 
Rutaceae 
44. Evs. once pinnately compound 
45 
44. Evs. twice or thrice pinnately compound 
Eeguminosae 
45. 
Eflts. 1-3 cm. long, oval, entire 
Eeguminosae 
45. 
Eflts. 5-12 cm. long 
46 
46. Juice watery, ill-scented 
Simarubaceae 
46. Juice of bark resinous, sticky 
Anacardiaceae 
47. 
Stam. more than 10 
48 
47. 
Stam. not more than 10 
63 
48. Shrubs or trees 
49 
48. Herbs 
55 
49. 
Ov. inferior or mostly so(epigynous or perig- 
ynous) 
50 
49. 
Ov. obviously superior (hypogynous) 
52 
50. Evs. opposite 
51 
50. Evs. alternate; carp. 3-many 
Rosace^ 
50. Evs. alternate; carp. 2 
Saxifragaceae 
51. 
Fls. white 
Saxifragaceae 
51. 
Fls. chocolate brown 
Calycanthaceae 
