462 CORDIACE^E BORAGINACE^E. 



roundish tuberous form, is black externally, white and milky within, 

 and varies in size from that of a walnut to that of a moderate-sized 

 turnip. It contains a resin, in which its active properties reside. It 

 is used in the form of powder and tincture, as an active irritant 

 cathartic. The root of Convolvulus Scammonia yields a gummy resinous 

 exudation, which constitutes medicinal Scammony. The plant grows 

 abundantly in Greece, the Grecian Islands, and various parts of the 

 Levant. Scammony is procured by cutting the root across, and 

 collecting the milky juice which soon concretes. The drug is im- 

 ported into this country from Smyrna. Its active principle is a resin. 

 It is used medicinally as a drastic purgative, in the form of powder, 

 pill, and extract. A spurious kind of Scammony has been prepared 

 from the root of Convolvulus (Calystegia) sepium; and several plants be- 

 longing to the natural order Asclepiadacese yield a purgative exudation, 

 which has been used under the names of Montpellier and Bourbon Scam- 

 mony (^[ 124). The roots of some of the plants do not possess purgative 

 qualities, and have been used as articles of food. Batatas edulis (Con- 

 volvulus Batatas) yields the sweet Potato, which contains much saccharine 

 and amylaceous matter, and is used as food in tropical countries. The 

 species of Cuscuta, or Dodder, have acrid purgative properties. Their 

 seeds germinate in the soil, and the plants afterwards twine round 

 others, and become attached to them by means of suckers. They then 

 lose their connection with the soil, and are supported as true parasites. 

 In this way they often destroy crops of Flax and Clover. 



957. Order 132. Coniiaeere, the Cordia Family. (Monopet. Hy- 

 pog.) Calyx 4-5-toothed, inferior. Corolla monopetalous, 4-5-cleft, 

 regular. Stamens inserted on the corolla, alternate with its segments; 

 anthers versatile. Ovary free, 4-8-celled ; ovules solitary, pendulous, 

 anatropal; style continuous; stigma 4-8-cleft. Fruit drupaceous, 

 4-8-celled. Seed exalbuminous, pendulous from the apex of the cell 

 by a long funiculus, upon which it is tiirned back ; radicle superior ; 

 cotyledons plaited longitudinally. Trees, with alternate, rough, ex- 

 stipulate leaves, and panicled flowers. They are chiefly natives of 

 warm countries. Some yield edible fruits ; their bark is occasionally 

 bitter, tonic, and astringent, and their wood is used for various econo- 

 mical purposes. The succulent, mucilaginous fruits of Cordia Myxa 

 and Sebestena, receive the name of Sebesten Plums. There are 11 

 genera enumerated by Lindley, including 180 species. Examples 

 Cordia, Varronia. 



958. Order 133. Boraginacete, the Borage Family. (Monopet. Hy- 

 pog.) Calyx persistent, with 4-5 divisions (figs. 660, 661 c). Corolla 

 gamopetalous, hypogynous, usually regular (figs. 296, 297), 5- rarely 

 4-cleft; aestivation imbricated (figs. 660, 661 p p). Stamens inserted 

 on the corolla, equal in number to its segments, and alternate with 

 them (fig. 661 e). Ovary usually 4-lobed, quadrilocular (fig. 661 o); 



