676 CONVOLVULACEAE 



5-15 cm. long, acute, entire; sepals ovate or orbicular-ovate, 5-10 mm. long, the 

 inner larger than the outer; corolla pink-purple, 5-7 cm. long. Bush Morning 

 Glory, Big Root. Plains and prairies; S.D. — Tex. — N.M. — Mont. Plain. 

 Je-Au. 



2. I. purpurea (L.) Roth. Annual; stem high, climbing, twining, retrorsely- 

 hirsute; leaf-blades cordate, short-acuminate; flowers umbellate on long peduncles; 

 calyx bristly-hairy; corolla purple or rarely pink or white, 4.5-7 cm. long. Com- 

 mon Morning-glory. Cultivated ground, waste places, etc.: N.S. — Fla. — Tex. 

 — Colo.; escaped from cultivation; native of trop. Am. 



4. CONVOLVULUS (Tourn.) L. Bindweed, Morning Glory. 



Annual or perennial, trailing or twining herbaceous vines, rarely shrubs. 

 Leaves alternate, usually sagittate or cordate at the base. Flowers perfect, 

 regular, solitary or clustered, on axillary peduncles. Sepals 5, rarely equal, or 

 the outer larger. Corolla fimnelform or campanulate, with plaited, entire, 

 5-angled or 5-lobed limb. Stamens 5, included; filaments filiform or dilated at 

 the base. Ovary 1-2-celled; styles united; stigmas linear to oblong; ovules 4. 

 Capsule subglobose, 2-4-valved. Seeds glabrous. 



Calyx not closely subtended by the bracts. 



Plant not canescent; leaf-blades hastate, but otherwise entire. 



Whole plant glabrous or nearly so. 1. C. arvensis. 



Stem and lower surface of the leaves with scattered long hairs. 



2. C. ambigens. 

 Plant more or less canescent; leaves usually lobed or dissected. 



Main divisions of the leaf-blades ovate or oblong, obtuse, lobed; sepals aurlcled 

 at the base. 3. C. herniannioides. 



Main divisions of the leaf-blades linear, entire, the basal lobes usually deeply 

 cleft; sepals not auricled. 4. C. incanus. 



Calyx closely subtended and enclosed by the large bracts. 

 Plants climbing or trailing; bracts cordate. 



Leaf-blades hastate; the basal lobes often sinuate-dentate, acute; stem and leaves 



glabroua or shghtly hairy. 5. C. americanus. 



Leaf-blades more sagittate; basal lobes rounded, entire; stem and leaves densely 

 pubescent. 6. C. interior. 



Plants erect or decimibent: bracts oval or oblong. 7. C. Macounii. 



1. C. arvensis L. Stem branched at the base, prostrate or low-twining, 

 2-8 dm. long, glabrous; leaf-blades oblong or ovate-sagittate to linear-hastate, 

 1-5 cm. long, obtuse or acutish; basal lobes more or less spreading, acute; bracts 

 subulate; corolla white or rose-tinged, 1.5-2 om. long and broad. Waste places 

 and fields: N.S. — N.J. — Nev. — Wash. — B.C. Plain — Submont. Je-Au. 



2. C. ambigens House. Stem prostrate or trailing, 2-10 dm. long, finely 

 cinereous, or glabrate in age; leaf-blades ovate-oblong or triangular-oblong, 1.5- 

 4 cm. long, abruptly acute, truncate or nearly so at the base; basal lobes spread- 

 ing, acute, often subtoothed below; flowers axillary, solitary; corolla 1.5-2 cm. 

 long and about as broad, white or with pink stripes. River valleys and loose soil: 

 Mont. — N.M. — Calif. — Ore. Plain — Submont. Je-Au. 



3. C. herniannioides A. Gray. Stem branched at the base, spreading or 

 procumbent, 3-15 dm. long, silky-tomentose; leaf-blades ovate, oblong or oblong- 

 lanceolate, 1.5-7 cm. long, sinuately-toothed, cordate or sagittate at the base; 

 corolla white, 2-2.5 cm. long, 1.5-2 cm. wide, angulate. Dry ])lains: Tex. — s 

 Colo. Son. Ap-S. 



4. C. incanus Vahl. Stem branched at the base, procumbent, 3-10 dm. 

 long, cinereous; leaf-blades variable, linear-sagittate to lanceolate-hastate, with 

 the basal lobes spreading, more or less lobed, or pedately cleft, 2.5-5 cm. long, 

 often mucronate; sepals becoming 6-8 mm. long; corolla white or pink, about 

 12 mm. long, 15 mm. broad; lobes acuminate. Dry hills and plains: Neb. — 

 Ark. — Tex.— Ariz. Son. Je-Au. 



5. C. americanus (Sims) Greene. Stem twining, 1-3 m. high, glabrate; 

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

 or apiculate ; basal lobes more or less spreading, broadly triangular, with a smaller 

 lobe below; bracts broadly ovate-cordate, obtuse or acutish; corolla 4-5 cm. long, 

 5-7 cm. broad, pink or rose-purple. Closely related to C. scpium L., of Europe. 



