Spring Flora of Oklahoma 
169 
4-lobed. Stamens 4 or 2, inserted on the tube or throat 
of the corolla. Ovary sessile, superior, 1-2-celled, or 
falsely 3-4-celled. Style filiform, simple. Ovules 1-sever¬ 
al in each cavity of the ovary, peltate. Fruit apyxis, cir- 
cumscissle at or below the middle, or an indehiscent nut¬ 
let. 
I. PLANT AGO (Toum.) L. 
Acaulescent or leafy-stemmed herbs, the scapes arising 
from the axils of the basal or alternate leaves, bearing 
terminal spikes or heads of small greenish or purplish 
flowers. Calyx-segments equal, or two of them larger. 
Corolla salver-form, the tube cylindric, or constricted at 
the throat, the limb spreading in anthesis. Fruit a pyxis, 
mostly 2-celled. Seeds with flattened or concave faces. 
Flowers mainly dioecious; corolla lobes erect or closed 
over the capsules. 
Stamens 2; leaves linear to filiform. 
1. P. elongata. 
Stamens 4; leaves with comparatively broad blades. 
Bracts and calyx-lobes obtuse; seeds golden yellow. 
2. P. virginica. 
Bracts and calyx-lobes acute or acuminate; seeds 
red or fuscous. 3. P. occidentalis. 
Flowers perfect; corolla-lobes spreading or reflexed on 
top of the capsules. 
Annuals; heterogenous. 
Bracts not aristate, not over twice as long as the 
flowers. 4. P. Purshii. 
Bracts aristate, 2 or more times as long as the 
flowers. 
Bracts linear-subulate to tapering-linear; plants 
not drying dark brown. 5. P. spinulosa. 
Bracts strictly linear, except at the apex; plants 
drying dark brown. 6. P, aristata. 
