Spring Flora of Oklahoma 
xiii 
9a. Herbs with a colored calyx like a sympetal¬ 
ous corolla; stems with tumid joints; 
fruit an anthocarp. 
19. NYCTAGINACEZE. 37 
9b. Herbs with a calyx not corolla-like; fruit 
a utricle. 
18. CHENOPODIACEZE. 37 
6b. Carpels free or only united at the base. 
7a. Carpels several-many, distinct, not enclosed; 
stamens numerous. 
25. RANUNCULACEiE. 44 
7b, Carpels 1-4 enclosed in the perigynous disk; 
leaves simple or compound with stipules. 
34. ROSACEZE. 61 
C. Perianth none; sometimes a minute border, cup, or gland may 
represent the calyx. 
la. Herbs with milky sap. 46, EUPHORBIACE^E. 89 
lb. Trees or shrubs. 
2a. Leaves opposite. 67. OLEACEZE 130 
2b. Leaves alternate. 
3a. Leaves star-shaped, fragrant. 
31. ALTINGIACEAH. 5,9 
3b. Leaves not star-shaped; flowers imperfect. 
4a. Ovary 1-celled, many-seeded; seeds with a tuft of cot¬ 
tony hairs. to. SALICACEZE. 18 
4b. Ovary 2-celled; pistillate flowers 2 or more in each 
bract of the ament or head. 
11. BETULACEZE. 21 
II. Corolla sympetalous (petals more or less united) ; perianth 
composed of calyx and corolla, calyx may be minute or suppressed. 
A. Flowers hypogynous. 
la. Stamens free from the corolla, as many as the petals and 
alternate with them or twice as many or more. 
2a. Styles 2, distinct with united stigma; plants with milky 
sap and entire leaves, usually opposite or whorled. 
71. ASCLEPIADACEZE. 135 
2b. Choripetalous plants in which the petals are sometimes part¬ 
ly or completely united. 
3a. Ovary 1-celled with 1 parietal placenta ; leaves alternate, 
usually compound. 39. FABACEZE. 70 
3b. Ovary 1-celled; calyx like a sympetalous colored corolla ; 
stems with tumid joints. 
19. NY CTAGINA CEZE. 37 
3c. Ovary 2-celled with a single ovule in each cavity; herbs. 
45. POLYGALA CEZE. 88 
