390 MANUAL OF BOTANY 



Echium, Linn. ; Borago, Tourn. ; Cynoglossum, Linn. There 

 are nearly 700 species. 



Properties and Uses. — The plants of this order are chiefly 

 remarkable for their mucilaginous properties. 



Order 194. EheetiacEjE, the Ehretia Order. — Diagnosis. — 

 These .plants resemble the Boragiuaoese in most of their cha- 

 racters, but they differ in having their carpels so completely 

 united as to form a 2- or more-oeUed ovary ; in their terminal 

 style ; and drupaceous fruit. They are usually characterised also 

 by the presence of a small quantity of albumen in their seeds, 

 but this is sometimes absent. By Bentham and HooTier the 

 EhretiacecE are made a sub-order of the BoraginaceiE. 



Distribution and Numbers. — Chiefly tropical plants. Illus- 

 trative Genera : — Ehretia, Linn. ; Heliotropium, Linn. There 

 are about 300 species. 



Properties and Uses. — Unimportant. 



Order 195. Cordiace^, the Cordia Order. — Character. — 

 Trees with alternate scabrous leaves, exstipulate. Calyx and 

 corolla 5-merous ; cestivation of the corolla imbrioate-tvcisted. 

 Stamens 5, alternate with the segments of the corolla ; anthers 

 versatile. Ovary superior, 4 — 8-celled, with 1 pendulous ovule 

 in each cell : stigma 4 — 8-cleft. Fruit drupaceous, 4 — S-celled ; 

 frequently some of the cells are abortive ; placentas axile, 

 Seeds 1 in each cell, pendulous by a long cord ; albumen none ; 

 cotyledons plaited longitudinally. This order is combined by 

 Bentham and HooJcer with Boraginacece. 



Distribution and Numbers. — Natives almost exclusively of 

 tropical regions. Illustrative Genera : — Cordia, Plum. ; Var- 

 ronia, DC. There are more than 180 species. 



Properties am,d Uses. — The fruits of many species are edible ; 

 the bark of C. Myxa is reputed to be a mild tonic and astrm- 

 gent ; some species yield timber. 



Order 196. Convolvdlace.s;, the Convolvulus Order. — Cha- 

 r a c t e r. — Herbs or shrubs, generally twining or trailing, or some- 

 times erect ; sometimes leafless and parasitic ; juice frequently 

 milky. Leaves or scales alternate, exstipulate. Calyx inferior, 

 with deep divisions, much imbricate, persistent. Corolla 

 5-partit6 or 5-plaited, regular, deciduous, sometimes with scales 

 in its tube ; cestivation twisted, plaited or imbricate. Stamens 

 5, alternate with the lobes of the corolla. Disc annular, hypo- 

 gynous. Ovary 2- 3- or 4-celled, or the carpels are more or less 

 distinct ; styles 1 or 2, usually 2-fid ; ovules 1 — 2 in each cell 

 or carpel, erect. Fruit capsular, 1 — 4- celled, with septifragal 



