CONVOLVULACEAE. 233 



Calyx-lobes obtuse: corolla-limb over 5 cm. wide. ]. /. pandurata. 



Calyx-lobes acute or acuminate : corolla-limb less than 5 cm. wide. 2. I. lacunosa. 



1. I. pandurata (L.) G. F. W. Mey. Perennial by a huge root: stems gla- 

 brous or glabrate, trailing or twining: leaf -blades ovate, often fiddle-shapecl, 

 3-10 em. long: peduncles 5-10 cm. long, 1-5-flowered: calyx-lobes oblong, 

 12-18 mm. long, obtuse, erect, imbricate and forming a tube: corolla 7-10 cm. 

 broad; tube lavender within. — Common, in waste places and cultivated 

 grounds. — Wild potato-vine. Man-of-the-earth. 



2. I. lacunosa L. Annual : stems twuuing, sparingly hirsute or glabrate : leaf- 

 blades ovate, entire or 3-lobed, 2-7 cm. long, deeply cordate: peduncles 1-3- 

 flowered : calyx-lobes oblong or ovate, 10-12 mm. long, acute or acuminate: 

 corolla 1.5-2 cm. long; limb often purple-margined. — Susquehanna valley. 

 Frequent, on islands. — Schists. 



3. PHARBITIS Choisy. Annual (ours), or perennial, climbing or trail- 

 ing vines. Leaf -blades entire, lobed, or angled. Calyx-lobes equal or unequal, 

 herbaceous, each with a pubescent base and a narrow tip. Corolla white, blue, 

 or purple, funnelform. Ovary 3-5-celled. Seeds smooth. — Sum. and fall. — 

 Morning-glory. 



Calyx-lobes 1-1.5 cm. long, the tips acute or acuminate. 1. P. purpurea. 



Calyx-lobes 2-3 cm. long, the tips elongate. 2. P. hederacea. 



1. P. purpurea (L.) Voigt. Stems twining: leaf -blades ovate or orbicular- 

 ovate, 6-18 cm. long, short-acuminate, cordate: calyx-lobes 10-15 mm. long: 

 corolla 5-7 cm. long; limb purple or sometimes pink, blue, white, or varie- 

 gated, 4-6 cm. broad. — Common, in waste places. Nat. of trop. Am. — 

 Common morning-glory. 



2. P. hederacea (L.) Choisy. Stems twining: leaf -blades 5-12 cm. long, 

 deeply 3-lobed; lobes acuminate: peduncles usually shorter than the petioles: 

 calyx-lobes 2-3 cm. long, the bases ovate or oval: corolla 3-4.5 cm. long, deep- 

 blue, or the tube white ; limb about 3 cm. broad. — S. Occasional, in cultivated 

 grounds. Nat. of trop. Am. 



4. CONVOLVULUS [Tourn.] L. Annual or (ours) perennial, trailing 

 or twining vines. Leaf-blades usually hastate or cordate at the base. Flowers 

 solitary, or clustered on axillary peduncles. Calyx naked or subtended by 

 bracts. Calyx-lobes equal or the outer longer. Corolla funnelform or campanu- 

 late. Ovary 1- or 2-celled. Ovules 4. Capsule globose or nearly so. Seeds 

 glabrous. — Sum. — Bindweed. 



Calyx enclosed by 2 large bracts which subtend it. 

 Stems trailing or twining. 



Leaf-blades broadly hastate or triangular-hastate : corolla single. 



1. C. americaniis. 



Leaf-blades narrowly hastate : corolla double. 2. 0. joponinis. 



Stems erect or ascending. 3. C. spithameus. 



Calyx without bracts. 4. G. arvcnsls. 



1. 0. americanus (Sims) Greene. Stems twining, 1-3 m. long, glabrate. 

 Leaf-blades broadly hastate or ovate-hastate, 5-12 cm. long, acuminate or 

 apiculate: peduncles as long as the leaves or longer: bracts 2-3 cm. long: 

 corolla pink or rose-purple, 5-7 cm. broad. — Common, in thickets, fields, and 

 fence-rows. — Hedge-bindaveed. 



2. C. japonicus Thunb. Similar to C. americanus in habit, but usually smal- 

 ler: leaf -blades narrowly hastate: corolla double, pink, mostly 4-5.5 cm. wide. 

 — E. Occasional, in fields. Nat. of Japan. 



