CONVOLVULACE^ SOLANACE^ 



329 



white, opening once at night, with a slender tube and a large limb 

 across. Trop. Amer. Perennial. 



I. purpurea, Roth. Morning-glory. Fig. 217. 

 broadly cordate-ovate, entire : flowers 2-4, large and 

 shaped, 2-3 in. long, purple to streaked and 

 white. Trop. Amer. Annual. 



I. hederacea, Jacq. Leaves heart-shaped, 

 3-5 lobed: flowers 1-3, rather smaller than those 

 of I. purpurea. Trop. Amer. Annual. 



I. Batatas, Poir. Sweet potato. Creeping: 

 leaves heart-shaped to triangular, usually lobed : 

 flowers (seldom seen) 3 or 4, light purple, 

 funnelform, 1% in. long. Tropics; 

 grown for its large edible root-tubers. 



2. CtSCUTA. DODDER. 



Parasitic twiners without foliage ( leaves reduced 

 to scales) : flowers in clusters, the calyx and corolla 

 with 4-5 lobes ; fruit 2-loculed, 4-seeded. ( See p. 89. ) 



C. Grondvii, Willd. (Fig. 487), is the common- 

 est species, twining its slender coral-yellow stems 

 over coarse herbs in swales: corolla bell-shaped, 

 the tube longer than the blunt and spreading lobes. 



4-6 in. 



Leaves 

 funnel- 



487. Cuscuta 

 Gronovii. 



XXII. SOLANACE^E. NIGHTSHADE FAMILY. 



Herbs or shrubs, with alternate often compound leaves: flowers 

 perfect and regular, 5-merous, mostly rotate or open -bell -shaped 

 in form and plaited in the bud: stamens 5, often connivent around 

 the single 2-loculed pistil, borne on the corolla: fruit a berry or 

 capsule (the latter sometimes 4-loculed by a false partition), the 

 seeds borne on a central column. Some 70 genera and 1,500 species. 

 Common representatives are nightshade, potato, tomato, husk tomato, 

 tobacco, jimson-weed, petunia. 



A. Fruit a fleshy berry. 



B. Stamens with anthers equaling or exceeding the fila- 

 ments. 



c. Anthers separate, opening at top 1. Solanum 



cc. Anthers united, opening lengthwise 2. Lycopersicum 



BB. Stamens with anthers much shorter than filaments.. 3. Capsicum 

 AA. Fruit a capsule. 



B. Calyx 5-parted to near the base 4. Petunia 



BB. Calyx toothed, not deep-parted. 



c. Pod usually prickly, large 5. Datura 



cc. Pod not prickly, small *. . . . 6. Nicotiana 



