CONVOLVULACE^. 



543 



corolla, and alternate with its lobes (fig. 764 e) ; filaments included 

 or exserted, equal or unequal. Disk annular, hypogynous. Ovary- 

 free, 2-4-celled, rarely by abortion 1 -celled ; ovules definite, erect, 

 when more than one, collateral ; style 1 (fig. 764 s), usually bifid, 

 rarely 2 ; stigmas obtuse or acute (fig. 765). Fruit succulent or 

 capsular (fig. 766), 1-4-celled, with septifragal and septicidal, or cir- 

 cumscissile dehiscence. Seeds albuminous ; embryo curved or spiral 

 (figs. 769 ; 598, p. 335) ; cotyledons corrugated (fig. 768) or incon- 

 spicuous ; radicle inferior. — Herbs or shrubs, usually twining, some- 

 times parasitical, often with a milky juice, and with alternate, un- 



Fig. res. 



Fig. 766. 



Fig. 768. 



Fig. 769. 



divided or lobed, exstipulate leaves, rarely leafless. They occur chiefly 

 in tropical and temperate regions. A few only are found in cold 



Figs. 762-769. Organs of fructification of Convolvulus (Calystegia) seplum, to illustrate 

 the natural order Convolvulacese. Fig. 762. Dia^am of the flower, showing two hracte 

 five unequal divisions of the imbricated calyx, five lobes of the plicate contorted corolla, 

 five stamens alternating with the corolline lobes, and a quadrilocular ovary. Fig. 763. 

 Flower bud. i. Large bracts, c. Calyx, p. Corolla. Pig. 764. Vertical section of the 

 lower part of the flower. 6, Bracts, c, Calyx p. Tube of corolla, bearing the filaments 

 of the stamens, e. o. Ovary, i. Style. Fig. 765. Summit of the style and stigmas. 

 Fig. 766. Fruit, /, suiTounded by the calyx, c, and the bracts, 6, which are persistent. 

 Fig. 767. Seed. A, Hilum. Fig. 768. Section of the seed, showing the corrugated coty- 

 ledons. Fig. 769. Embryo separated. 



