CONVOLVULACEjE. 



619 



same, and to the scrophuLuinae. But it is dis- 

 tinguished from the former by its cylindrical 

 stem, alternate leaves, regular corolla, stamina 

 five in number, and from the latter by the struc- 

 ture of its ovary and fruit. 



Among the genera are the following. 



Sect. I. Genera without appendages to the 

 corolla : echium, lithospermum, pulmonaria, onos- 

 ma, cordia, &q. 



Sect. II. Genera furnished with appendages : 

 Symphytum, lycopsis, anchusa, borago, cynoglos- 

 sum, &c. 



Ventenat proposed separating from the bora- 

 ginefe the genus cordia, on account of its simple 

 and fleshy fi-uit, and forming of it a family 

 under the name of sehesienm. Mr Brown thinks 

 that the genera liydrophyllum, ellisia, and pha- 

 celia, which have a capsular fruit, a large horny 

 endosperm, and compound or deeply-lobed leaves, 

 form a distinct family, which he names hydro- 

 phyllce. Lastly, Professor Schrader, in his excel- 

 lent memoir on the boragiueae, proposes to divide 

 them into three distinct orders : boragenew, 

 hydropliyllece, and heliotropicece. 



The plants of tliis family are common in 

 Europe, and the north of Afiica, less abundant 

 in India, and the equatorial regions, and not 

 unfrequent in New Holland ; they are mucilagi- 

 nous and emollient, but possess no properties 

 that qualify them to be of much importance as 

 food or medicine ; many species are mere weeds, 

 otliers are beautiful ornamental flowers. The 

 roots of anchusa tinctoria, lithospermum tinctor- 

 ium, anchusa virginica, and some other species, 

 are used to dye a red colour. Pure nitre has 

 been found in several species. 



CoNVOLVULACE^, Jussieu. Herbaceous or suf- 

 frutescent plants, often voluble and climbing, 

 having alternate leaves, which are simple, or 

 more or less deeply lobed ; axillar or tei-minal 

 flowers ; a monosepalous, persistent calyx, with 

 five divisions ; a monopetalous, regular corolla, 

 with five plicate lobes ; and five stamina inser- 

 ted into the tube of the corolla. The ovary is 

 simple and free, supported upon a hypogynous 

 disk, and has from tvro to four cells containing 

 a small number of ovules. The style is simple 

 or double. The fi-uit is a capsule having from 

 one to four cells, usually containing one or two 

 seeds, attached towards the base of the dissepi- 

 ments. It opens into two or four valves, the 

 edges of which are applied upon the dissepi- 

 ments which remain in place. More rarely the 

 capsule remains closed, or opens into two super- 

 imposed valves. The embryo, of which the 

 cotyledons are flat and plicate, is rolled upon 

 itself, and placed in the centre of a soft and as it 

 were mucilaginous endosperm. 



The essential character of this family consists 

 in its capsule, the sutures of which correspond 

 to the dissepiments. This character being want- 



ing in some genera formerly united witli the 

 convolvulaoeae, such as hydrolea, nama, sagonea, 

 and diapensia, Mr Brown has px-oposed forming 

 them into a distinct family under the name of 

 hydroleaceas. The principal genera of the con- 

 volvulaceffi are convolvulus, ipomaa, cuscuta, 

 CDolimlus, cressa, &c. 



The roots are generally acrid and purgative. 

 Jalap is obtained from convolvulus jalapa, and 

 scammony from c. scammonia. The root of c. 

 panduratus is used as a purgative in Nortli 

 America, and those of many other species pos- 

 sess the same properties. On the other hand, 

 those of the sweet potato (c. batatas) and edulis 

 are articles of food. Several species are garden 

 flowers. 



PoiEMONiACE^, Jussieu. Herbaceous or woody, 

 sometimes twining plants, furnished with alter- 

 nate or opposite leaves, often divided and pinna- 

 tifid, and axillar or terminal flowers, forming 

 branched racemes. Each flower is composed of 

 a five-lobed, monosepalous calyx ; a regular, sel- 

 dom irregular, monopetalous corolla, with five 

 more or less deep divisions ; five stamina inser- 

 ted into the corolla ; an ovary applied upon a 

 disk which is often spread out at the bottom of 

 the flower and lobed. This ovary has three cells, 

 containing one, or more frequently several 

 ovules. The style is simple, terminated by a 

 trifid stigma. The fruit is a three-celled cap- 

 sule, opening by three valves, which ai-e septi- 

 ferous on the middle of their inner face, or only 

 bear the impression of the dissepiment, which 

 remains untouched at the centre of the capsule. 

 The seeds have an erect embryo in the centre of 

 a fleshy endosperm. 



This family is in some measure intermediate 

 between the convolvulaceoe and bignoniacese. It 

 differs from the former in having its valves sej)- 

 tiferous in the middle of their inner surface, and 

 not contiguous at their margins over the disse- 

 piments, and in its erect embryo ; from the lat- 

 ter, in having the corolla almost always regular, 

 the ovai-y three-celled, its valves septiferous, &c. 

 The genera which compose this family are in 

 small number : polemonium, phlox, cantua, hon- 

 plandia, and probably cohma. They are natives 

 of the mountainous parts of Europe. Some are 

 showy plants but possess no remarkable pro- 

 perties. 



BiGNONiACB^, Jussieu. Bignoniaceae, and 

 Pedalinete, Brown. Trees, shrubs, or more 

 rarely herbaceous plants, with the stem often 

 sarmentose and furnished with cirri. The leaves 

 are commonly opposite or temate, rarely alter- 

 nate, usually compound. The flow^ers, which 

 are terminal, or axillar, and variously grouped, 

 have a monosepalous, often persistent, five-lobed 

 calyx, a monopetalous corolla, more or less irre- 

 gular, and with five divisions. The stamina are 

 commonly four and didynamous, accompanied 



