ASCLEPIADACEAE. 231 



11. A. quadrifolia Jacq. Stems 3-6 dm. tall, sometimes puberulent: leaf- 

 bkules ovate to ovate-lanceolate, 4-10 em. long: corolla-lobes pink or nearly 

 white, about 5 mm. long: hoods ovate-oblong, A-5 mm. long, about twice as 

 long as the androecium; horn slender, much shorter than the hood: follicles 

 10-12 cm. long. — Common, in woods. 



12. A. verticiUata L. Stems 3-8 dm. tall, commonly pubescent in lines: leaf- 

 blades narrowly linear to linear-filiform, 2-6 cm. long: corolla-lobes greenish- 

 white, 3-4 mm. long: hoods about 1 mm. long^ about equalling the androecium 

 or shorter, with erect auricles within; horn slender, much exceeding the hood: 

 column mostly less than 1 mm. long : follicles 7-10 cm. long. — Common, in 

 dry soil and fields. 



3. VINCETOXICUM Walt. Stout vines with broad leaf-blades. Calyx- 

 lobes longer than the corolla-tube. Corolla rotate or campanulate: lobes often 

 relatively long. Crown saucer-shaped or cup-like, sometimes lobed, single or 

 double. Stigma flat or depressed. 



1. V. oblicLUum (Jacq.) Britton. Leaf -blades broadly ovate to orbicular- 

 ovate, 7-20 cm. long, the basal lobes mostly forming a closed sinus by the over- 

 lapping edges: calyx-lobes about 3 mm. long: corolla reddish-purple; lobes 9-14 

 mm. long: crown with the longer lobes truncate or emarginate: follicles 7-8 

 cm. long: seeds about 7 mm. long. — Susquehanna valley. Occasional, in 

 woods and thickets. — Sum. — Angle-pod. 



Order POLEMONIALES. 



Herbs, or sometimes shrubs or trees, the plants of some groups para- 

 sitic. Leaves with dilated blades, or scale-like. Flowers mainly perfect. 

 Calyx of partially united sepals. Corolla of partly united petals, regular 

 or irregular. Androecium of as many stamens as there are corolla-lobes, 

 or fewer, sometimes partly represented by staminodia, or partly obsolete. 

 Gynoeeium of 2 distinct or several united carpels. Ovary superior. Fruit 

 a capsule, a berry, or a drupe, or a group of nutlets, or utricle-like. 



Stamens 5. 



Fruit capsular or baccate : ovary not 4-lobed. 

 Styles or stigmas distinct. 



Ovary 1-2-celled, or rarely 4-celled : stigmas 2. 

 Ovary 2-celled or 4-celled. 



Corolla unappendaged within : plants with well-developed leaves, at 

 least if vines. Fam. 1. Convolvulaceae. 



Corolla appendaged within : parasitic 



twining plants with scale-like leaves. Fam. 2. Cuscutaceae. 

 Ovary 1-celled. Fam. 3. Hydroleaceae. 



Ovary 3-celled : stigmas 3. 



Calyx-lobes imbricate : corolla mostly 



plaited in the bud. Fam. 1. Convolvulaceae. 



Calyx-lobes valvate : corolla merely con- 

 volute in the bud. Fam. 4. Polemoniaceae. 

 Styles or stigmas wholly united. 



Median axis of the gynoeeium in the same 



axis as the stem : seeds mostly pitted. Fam. 5. Solanaceae. 

 Median axis of the gynoeeium not in the axis 



of the stem : seeds mostly tuberculate. Fam. 10. Rhixanthaceae. 



Fruit drupaceous, or of 2 or 4 nutlets. Fam. 6. Boraginaceae. 



Stamens 4 and didynamous, or 1 or 2. 



Carpels ripening into a group of 4 nutlets, an 

 achene or a drupe. 

 Style apical on the lobeless ovary. 



Ovary 2-celled. Fam. 7. Verbenaceae. 



Ovary 1-celled. Fam. 8. Phrymaceae. 



Style ansmg between the 4 lobes of the ovary. Fam. 9. Lamiaceae. 

 Carpels ripening into a capsule. 



