134 
Spring Flora of Oklahoma 
minate, shorter than the purple corolla. Corolla lobes obovate, about 
4 times as long as the tube. Capsule oblong, pointed. 
On prairies. May-August. Kingfisher, Cleveland and Grady 
counties. 
FAMILY 70. APOCYNACEiE. Dogbane Family. 
Perennial herbs, shrubs or vines, mostly with an acrid, 
milky juice, with simple, opposite, alternate or verticil- 
late, ex-stipulate leaves, and perfect, regular, 5-parted, 
cymose, solitary or paniculate flowers. Calyx inferior, 
persistent. Corolla gamopetalous, its lobes convolute in 
the bud. Ovary superior, or its base adherent to the 
calyx. Fruit usually of 2 follicles or drupes. 
Leaves alternate; erect herbs. I. Amsonia. 
Leaves opposite; vines or herbs. II. Apocynum. 
I. AMSONIA Walt 
Perennial herbs. Leaves alternate, entire. Flowers 
blue or bluish, in terminal, thyrsoid or corymbose cymes. 
Calyx 5-parted, acuminate. Corolla mostly salver-form, 
the tube dilated at the summit, villous within. Stamens 
inserted on the throat of the corolla, included. Disk none. 
Carpels 2, connected by the slender styles. Stigma ap- 
pendaged by a reflexed membrane. Follicles 2 together. 
1. Amsonia Amsonia (L.) Britton. Amsonia. Loosely pubes¬ 
cent or hairy when young, soon glabrous. Leaves from ovate-lan¬ 
ceolate to linear-lanceolate, taper-pointed. Calyx lobes about 1" 
long. Tube of the bluish corolla little longer than the lobes. Fol¬ 
licles 2'-4' long, about 2" thick. 
In moist soil. April-July. Comanche County. 
II. APOCYNUM L. 
Perennial, branching herbs, with opposite, entire 
leaves, and small, white or pink flowers in terminal and 
sometimes axillary corymbed cymes. Calyx 5-parted, 
acute. Corolla urceolate to campanulate, the tube bear- 
