Some species may exhibit a host preference, but most will grow upon a wide 

 range of herbaceous or woody plants including pteridophytes and grasses. A few 

 species show a predilection for cultivated crop plants, especially legumes and flax, 

 and sometimes cause considerable damage. In enumerating the host plants here 

 only those that grow in water or wetlands are cited. While commonly considered 

 to be wholly parasitic, many species show evidences of chlorophyll in the stems, 

 flowers or maturing fruits and are, therefore, at least partly autophytic. Additional 

 vernacular names to those above are "angel's hair," "tangle gut," "witches' shoe- 

 laces," "devil's gut," "strangle vine." 



1. Capsules circumscissile (that is, easily separating near the base in a more or 

 less regular line of cleavage) 1. C. umbellata. 



1. Capsules not circumscissile (that is, not separating in a regular line of cleav- 



age), when forcibly separated either coming away entirely or break- 

 ing very irregularly (2) 



2(1). Calyx gamosepalous; inflorescence not markedly bracteate or congested (3) 



2. Calyx deeply divided to form distinct or nearly distinct sepals; inflorescence 



with numerous bracts, loose or mostly compact (18) 



3(2). Calyx lobes with fleshy hornlike projections; corolla lobes strongly inflexed 



to essentially cover the capsule; flowers conspicuously papillate 



2. C. Warned. 



3. Flowers without all of the above characteristics (4) 



4(3). Styles short and subulate; interstylar aperture comparatively large; calyx 

 lobes commonly unequal (5) 



4. Styles longer and only slightly (if at all) subulate (6) 



5(4). Flowers mostly 5-parted 3. C. obtusiflora var. glandulosa. 



5. Flowers mostly 3- or 4-parted 4. C. Polygonorum. 



6(4). Flowers 3- or 4-parted; withered corolla capping the capsule 



5. C. Cephalanthi. 



6. Flowers 5-parted; withered corolla rarely capping the capsule (7) 



7(6). Calyx conspicuously 5-angled by the projecting lobes where they overlap 

 at the sinuses 6. C. pentagona. 



7. Calyx not obviously 5-angled (8) 



8(7). Capsules depressed-globose or globose, not at all ovoid or evidently 

 thickened about the style bases, commonly about as wide as long 

 (9) 



8. Capsules globose-ovoid, apically narrowed, mostly more or less thickened 



about the style bases (11) 



9(8). Calyx lobes overlapping at the base; withered corolla about the lower part 

 of the smooth capsule 7. C. campestris. 



9. Calyx lobes scarcely overlapping; withered corolla surrounding the capsule 



which is typically papillate about the top (10) 



10(9). Calyx and pedicels not papillate 8. C. glabrior var. glabrior. 



10. Calyx and pedicels papillate 8. C. glabrior var. pubescens. 



11(8). Corolla lobes acute, with inflexed or erect tips (12) 



11. Corolla lobes obtuse or rounded at apex (15) 



12(11). Flowers commonly smooth, 5-parted; scales shorter than corolla tube; 

 capsules usually 1-seeded 9. C. salina. 



12. Flowers typically fleshy, papillate; capsules mostly 2- to 4-seeded (13) 



13(12). Flowers mostly 4-parted; scales represented by wings that are shorter 

 than the corolla tube 10. C. Coryli. 



13. Flowers 5-parted; scales well-formed, reaching the filaments (14) 



1360 



