129 



CONVALLARITES. 



CONYZA. 



130 



entirely destitute of varicose sutures, and by their never having any 

 appearance of a notch near the lower extremity of the outer lip ; the 

 young Strombi moreover are seldom, if ever, so regularly conical ; 

 and from the young Cyprceoe by the thickness of their shell, by the 

 coronated or abrupt spire, and by their not being naturally polished 

 in every part, which the Cijpntte always are, in consequence of the 

 want of epidermis which covers the shell of the Cone, while in the 

 Cypnea the large mantle comes in contact with the whole of the shell. 



Shell of Cunui gtnrralii. 



CONVALLARITES, a genus of Liliaceous (?) Plant*, fossil in the 

 Red-Sandstone of Sulzbad. (Brougniart.) 



C'ONVOLVULA'CE^E, a natural order of Monopetalous Exogenous 

 Plants, with bell-ahaped flowers, opening or contracting beneath the 

 influence of light, a plaited aestivation of the corolla, 5 stamens, and a 

 fruit with 2 or 3 cells, in which 1 or 2 ovules stand erect. The 

 embryo is crumpled up in the midst of very firm albumen. The 

 common Bind- Weeds of the hedges, the 1 pomace and Convolvuli of the 

 gardens, offer illustrations of the ordinary state of thia order, the 

 species of which have purgative roots ; and in the case of scammony, 

 yielded by C'mvohultu Scammonia, and of jalap, produced by various 

 species of fpomcea [IPOSNKA], are of great medicinal importance. 

 Occasionally the purgative principle is so much diffused among the 

 frecula of the root as to be almost inappreciable, as in the case in the 

 Convolvulus Batatat, or Sweet Potato of America, which was the 

 forerunner of the common potato, and gave it its name, and which is 

 still cultivated in the south of Spain and France. [BATATAS.] 



1, a bracteal leaf of Ifeuropeltit racfiiiota, with a flower growing from its 

 midrib ; 2, one of its flowers magnified ; 3, a corolla opened, showing the 

 stamens; 4, a small cluster of flowers; 5, one of its ovaries with two styles; 

 6, a section of the calyx of a Canvohulut ; 7, half a capsule, with valves sepa- 

 rating by their edge from the dissepiments ; 8, a transverse section of a seed, 

 showing a part of the embryo lying in the albumen. 



In most instances the sterna of this natural order are twining, and 

 in such cases it is immediately recognised ; but occasionally they are 

 erect and more spiny, and when that happens it is not so easy to 



HAT. H13T. DIV. VOL. II. 



know the order. If however attention is paid to the very imbricated 

 state of the calyx, two of the sepals being quite exterior with respect 

 to the other three, no real difficulty in identifying it need be experi- 

 enced. For illustration we have taken a singular East Indian genus 

 called Neuropdtis, in which the flowers grow from the midrib of the 

 bracteal leaves. 



The species are abundant in all parts of the tropics, but rare in 

 cold climates where only a few are found. In the coldest climates 

 they are unknown. The roots abound in a milky juice, which is 

 strongly purgative : this property depends on a peculiar resin 

 which is the active principle of jalap, scammony, and others of like 

 nature. There are 43 genera and above 600 species. The order, 

 according to Dr. Lindley, is allied to Solanacea, Boraginacece, and 

 Nolanacece, 



CONVOLVULUS, a genus of Plants belonging to the natural 

 order Conrolvulacece. The species are chiefly herbs or herb-shrubs. 

 The genus is known by the style being divided into 2 linear arms 

 and its ovary having 2 cells in which stand 2 erect ovules. There 

 are above 130 species of this genus. They are commonly known by 

 the name of Bind-Weeds. 



C. Scammonia, Scammony Bind-Weed, is a native of Syria, Cappa- 

 docia, and of the island of Rhodes, in hedges. It has large campanu- 

 late cream-coloured or very pale red corollas. The roots, which are 

 very long and thick, when fresh contain a milky juice. This is 

 obtained by removing the earth from the upper part of the roots, and 

 cutting off the tops obliquely. The milky juice which flows out is 

 collected in a vessel in the earth at the lower end of the cut. Each 

 root furnishes a few drachms, and the produce of several roots is 

 added together, and then dried in the sun. This is the true and una- 

 dulterated Scammony. It is light, of a dark gray colour, and becomes 

 of a whitish-yellow when touched with the wet finger. It seldom 

 reaches us in a pure state, but is commonly mixed with the expressed 

 juice of the root, and often with flour, sand, or earth. The best comes 

 from Aleppo, and a second quality from Smyrna. Scammony is 

 an efficaceous and powerful purgative. [SCAMMONY, in ARTS AND 

 Sc. DIV.] 



C.arventit has angular striated stems; leaves sagittate, somewhat auri- 

 cled; peduncles usually 1 -flowered; sepalsovate, roundish ; corolla white 

 or rose-colour. It is native throughout Europe in sandy fields and by 

 road-sides ; also in China, Persia, and some parts of India. It is very 

 common in Great Britain. This species is said to possess a purgative 

 quality, as also C. SoldaneUa, C. maritimut, and C. mawocarpus. 



C. pandurattu abounds in prussic acid, and is one of the plants from 

 which the liqueur Noyau is prepared. 



C. altraoida is a native of the South of Europe, North of Africa, 

 and Levant, climbing among bushes. It has stems branched from the 

 bottom, climbing or spreading, taper and leafy ; the corolla about two 

 inches long, and of a beautiful rose-colour. According to M. Loiseleur 

 Deslongchampa the roots contain a purgative resin, which is given in 

 doses from 15 to 24 grains. 



C. SoldaneUa and C. sepium are now referred to the genus Calystegiu 

 by Robert Brown. [CALYSTEGIA.] Several of the species are natives 

 of Great Britain. Many grow well in our gardens, and form handsome 

 and showy flowers. 



CONY'ZA, a genus of Plants belonging to the natural order Com- 

 porita, to the sub-order Tubuliflorae, the tribe Eupatorlacete, the sub- 

 tribe Baccharvlece, the division Conyzeoe, and the sub-division Enco- 

 nyzeai. It has an herbaceous imbricate involucre, the flowers of the 

 ray tubular, 3-toothed, pistiliferous, those of the disc tubular, 5- 

 toothed, hermaphrodite ; the anthers caudate, the achenium beakless, 

 the pappus pilose, the receptacle naked. The species are herbs and 

 shrubs, and are found in Europe, Asia, Africa, and America. 



C. tquamoia, Fleabane, Ploughman's Spikenard, has the scales of 

 the involucre all linear, the leaves ovate-lanceolate, downy, denticulate, 

 the lower leaves narrowed into a footstalk, the florets of the ray sub- 

 ligulate, the fruit terete. This is a common plant on calcareous soils, 

 in Great Britain and throughout Europe. It possesses a volatile oil 

 with a peculiar scent, and is used for the purpose of driving away 

 fleas and gnats. It seems to have had this reputation from an early 



feriod, as its names in most languages have reference to this quality. 

 U Latin name is Pvlicaria ; French, Herbes aux Puces ; English, 

 Fleabane. This species has been referred by De Candolle, in his 

 ' Prodromus,' who is followed by Babiugton, in his ' Manual,' to the 

 genus Inla, under the name of /. Conyza. 



C. anthelmintica has ovate or oval-oblong leaves, acuminate at both 

 ends, coarsely serrated, and downy ; the heads corymbose, each con- 

 taining 40-50 florets ; the scales of the involucre lanceolate, linear, 

 acute, the outer somewhat spreading, leafly, and obovate-linear. It is 

 a common plant among rubbish and in dry uncultivated ground in 

 the East Indies. It is the Vernonia anthelmintica of Willdenow. 

 The fruit is used by the doctors of India as a powerful remedy for 

 worms. 



C. gcnittelloidet has very small leaves reduced to sharpish somewhat 

 ternate scales ; 1-2 heads in interrupted spikes, the involucre turbinate, 

 with the scales all acuminate. This plant is a native of Peru and 

 Brazil. It is the Baccharit genwteUoid.es of Persoon, the Molina 

 reticulata of Leasing. It contains a bitter extractive matter and an 

 aromatic oil, and is not unlike in its medicinal characters the common 



