374 CONVOLVULACE^E. (CONVOLVULUS FAMILY.) 



ORDER 75. CONVOl,VUL,ACEJE. (CONVOLVULUS FAMILY.) 



Chiefly twining or trailing herbs, often with some milky juice, ivith alter- 

 nate leaves (or scales) and regular 5-androus flowers ; a calyx of 5 imbricated 

 sepals ; a 5-plaited or 5-lobed corolla convolute or twisted in the bud ; a 2- 

 celled (rarely %-celled) ovary, or in one tribe 2 separate pistils, with a pair 

 of erect ovules in each cell, the cells sometimes doubled by a false partition 

 between the seeds, so becoming ^-celled ; the embryo large, curved or coiled 

 in mucilaginous albumen. Fruit a globular 2-6-seeded pod. Flowers 

 mostly showy, on axillary peduncles : pedicels articulated, often 2-bracted. 

 (Many are cultivated for ornament, and one, the Sweet Potato, for its edi- 

 ble farinaceous roots : those of several species are cathartic ; e. g. Jalap.) 

 There are three suborders, or rather strongly marked tribes. 



Tribe I. CONVOLVULE^. Leafy plants, mostly twiners. Ovary 2-4-celled. Pod 

 usually septifragal. Embryo with broad and leaf-like cotyledons, crumpled in the seed. 



* Style single and undivided. 

 - Calyx naked, i. e. not enclosed or surrounded by leafy bracts. 



1. Quamoclit. Stamens and style exserted. Corolla salver-shaped or nearly so. Stigma 



capitate-2-lobed. Pod 4-celled ; the cells 1-seeded. 



2. Ipomcea. Stamens included. Corolla funnel-form or bell-shaped. Stigma capitate, often 



2 - 3-lobed. Pod 2 - 3-ceUed , the cells 2-seeded. 



3. Convolvulus. Stigmas 2, elongated, linear. Otherwise much as in Ipomoea. 



- *- Calyx surrounded and enclosed by a pair of broad leafy bracts. 



4. Caly stegia. Stigmas 2, linear or oblong. Pod imperfectly 2-celled, 4-seeded. 



* * Style single and 2-cleft, or styles 2, rarely more. Prostrate or spreading herbs. 



5. Bonamia. Styles 2 and undivided, or a single one 2-cleft : stigmas capitate. 



6. E volvulus. Styles 2, and each 2-cleft : stigmas obtuse. 



Tribe II. DICHONDRE3. Creeping plants. Ovaries as well as styles 2 or more. 

 Embryo, &c. as in the preceding tribe. 



7. Dichondra. Corolla bell-shaped, 5-cleft Pistils 2, one-seeded. 



Tribe III. CUSCUTINE^. Leafless parasitic twiners. Embryo spiral, slender, desti- 

 tute of cotyledons. Ovary 2-celled. Parts of the flower rarely in fours ! 



8. Cuscuta. The only genus of the group. 



1. QUAMOCLIT, Tourn. CYPRESS-VINE. 



Sepals mostly mucronate or awned. Corolla cylindrical-tubul-ar, with a small 

 spreading border, not twisted in the bud. Stamens and style protruded. Stigma 

 capitate-2-lobed. Pod 4-celled; the cells 1-seeded. Annual twiners, with red 

 or crimson flowers ; in summer. (An aboriginal, probably Mexican, name.) 



1. Q. cocciNEA, Moench. Leaves heart-shaped, acuminate, entire, or an- 

 gled; sepals awn-pointed; corolla light scarlet (1'long). (Ipomoea coccinea, 

 L.) River-banks, &c., Ohio to Illinois, Virginia, and southward. (Nat. from 

 Trop. Amcr. or Ind.) 



2. Q. VULG\RIS, Choisy. (CYPRESS- VINE.) Leaves pinnately parted into 

 linear-thread-shaped delicate parallel lobes ; peduncles 1 -flowered; corolla nar- 

 row, scarlet-red, and a white variety. Sparingly escaped from gardens south- 

 ward. (Adv. from India.) 



