184 COXVOLVULACEAE 



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 



glabrous or slightly haii-y. 5. C. americanus. 



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

 pubescent. 6. C. interior. 



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



Family lOS. CUSCUTACEAE. Dodder F.uiily. 



1. CtJSCUTA (Tourn.) L. Dodder, Love-vine, Cor.\l-vine. 



Stigmas elongate, linear: styles equal: capsule circumscissile. 



Corolla globose-urceolate : scales inside the corolla crenate. 1. C. gracilis. 



Corolla open-campanulate : scales inside the corolla deeply fringed. 



Calyx-lobes obtuse. 2. C. planiflora. 



Calyx-lobes acute. 3. C. Anthemi. 



Stigmas capitate; styles usually imequal. 



Capsule circumscissile; calyx and corolla-lobes acuminate; inflorescence umbel-like. 



4. C. umhellata. 

 Capsule jndehiscent or bursting irregularly. 

 Calyx gamosepalous, usually not bracted. 

 Capsule depressed-globose. 



Lobes of the corolla triangular or lanceolate, acuminate or acute. 



Calyx-lobes acute or acuminate: corolla-lobes erect or somewhat spread- 

 ing, in fruit comiivent: flowers pedicelled. o. C. californica. 

 Calyx-lobes rounded; corolla-lobes strongly spreading with inflexed tips, 

 flowers subsessile. 6. C. arvensix. 

 Lobes of the corolla oblong, very obtuse. 



Corolla deeply campanulate, 4-merous, about 2 mm. wide; tube longer 



than the calyx. 7. C. cephalanlhi. 



Corolla open-campanulate, about 4 mm. wide; tube shorter than the 

 calyx. 8. C. plattensis. 



Capsule ovoid-globose, acute. 

 Corolla-lobes not incurved. 



Lobes of the corolla and the calyx obtuse. 



Flowers less than 2 mm. long ; calyx-lobes very short, rounded and 



denticulate. 9. C. denticulata. 



Flowers 2.. 5-3 mm. long; calyx-lobes ovate, not denticulate. 



Scales incurved over the ovary; styles about half as long as 



the ovary or longer. 10. C. Gronovii. 



Scales appressed to the corolla-tube; styles one-third to one- 

 fourth as long as the ov^ary. 11. C. carta. 

 Lobes of the corolla and calyx acute. 12. C. salina. 

 Corolla-lobes incurved at the apex. 



Capsule 4 mm. or less broad; inflorescence rather open. 



13. C. indecora. 

 Capsule 5-6 mm. broad: inflorescence globular clusters. 



14. C. megalocarpa. 

 Calyx of 5 almost distinct and overlapping sepals, subtended by 2 or more similar 



bracts. 15. C. cuspidata. 



Family 109. POLEMONIACEAE. Phlox Family. 



Calyx wholly herbaceous: leaves pinnately compound. 1. Polemo.vium. 



Calyx more or less scarious between the lobes, or the lobes spinulose-tipped and pungent; 

 leaves simple or pinnatifld, but not compound. 

 Calyx distinctly enlargmg in fruit, not ruptiired by the capsule. 2. CoLl.OMl.v. 

 Calyx soon ruptured by the fruit, or if not ruptured, slightly if at all enlarged in 

 fruit and calyx-teeth spinescent. 

 Corolla strictly salver-shaped with a narrow throat. 



Perennials, with leaves opposite; seeds not mucilaginous when wetted. 



3. Phlox. 

 Annuals, with the floral leaves alternate: seeds mucilaginous wlien wetted. 



4. MiCROSTERIS. 



Corolla campanulate, fimnelform, trumpet-shaped, or if somewhat saiver-shaped, 

 the tliroat open. 

 Anthers sagittate at the base; calyx-lobes and 3-5-cleft bracts densely woolly, 



pungent. 5. Wel\\itschi.\. 



Anthers not sagittate: calyx-teeth and bracts usually not woolly, but if some- 

 what so. not pungent. 

 Corolla elongate, with a narrow tube and funnelform or spreading throat. 

 Caly.x-teeth either unequal in size or spinulose-laciniate. or both: pun- 

 gent-leaved annuals. 0. N.\v.\rreti.\. 

 Calyx-teeth neither unequal nor spinulose-laciniate; perennials or 

 non-pungent annuals. 

 Calyx not at all scarious in the sinuses; mostly undershrubs. with 

 pimgent leaves. 7. Leptodactylox. 



