=Bittersweet, Solanum dulcamara.=

4b. Not climbing; leaves toothed (flowers white)
=Nightshade, Solanum nigrum.=

5a. Climbing or trailing shrub, with purplish, white, or greenish
flowers about 1 cm. wide (frequently thorny; flowers in summer)
=Matrimony Vine, Lycium halimifolium.=

5b. Herbaceous plants, not climbing --6.

6a. Flowers white, red, or blue, 2.5 cm. or more wide (summer) --7.

6b. Flowers yellow, yellowish-white, or greenish-yellow (summer)
--12.

7a. Corolla-tube 10 cm. long or more (5-12 dm. high) --8.

7b. Corolla-tube 5 cm. long or less --10.

8a. Stem finely pubescent; leaves entire or nearly so
=Thorn-apple, Datura metel.=

8b. Stem glabrous; leaves coarsely toothed (Jimson Weed) --9.

9a. Stem green; corolla white =Jimson Weed, Datura stramonium.=

9b. Stem purple; corolla light-blue or purple
=Jimson Weed, Datura tatula.=

10a. Corolla pale-blue (5-10 dm. high)
=Apple of Peru, Nicandra physalodes.=

10b. Corolla, red or violet (2-4 dm. high)
=Petunia, Petunia violacea.=

10c. Corolla white --11.

11a. Corolla all white (2-4 dm. high) =Petunia, Petunia axillaris.=

11b. Corolla with yellow center
=White Ground Cherry, Physalis grandiflora.=

12a. Corolla 30 mm. wide or more, somewhat irregular; stamens
declined to one side (3-6 dm. high)
=Henbane, Hyoscyamus niger.=

12b. Corolla smaller, strictly regular --13.

13a. Flowers in terminal panicles; corolla tubular, with slightly
spreading lobes (5-10 dm. high) =Wild Tobacco, Nicotiana rustica.=

13b. Flowers solitary in the axils; corolla short, widely spreading (3-8
dm. high) (Ground Cherry) --14.

14a. Annuals with branching slender roots --15.

14b. Perennials with thickened roots and rootstocks --16.

15a. Plants pubescent =Ground Cherry, Physalis pubescens.=

15b. Plants smooth, or with a few scattered hairs
=Ground Cherry, Physalis ixocarpa.=

16a. Stem viscid-pubescent =Ground Cherry, Physalis heterophylla.=

16b. Stem glabrous o