Class XIX. 
SYNGENESIA. 
661 
of his countrymen, will place in one view the result of his labours, so as to enable the world to judge with more 
accuracy, both of their extent, and of their real importance in defining the limits of the genera and their orders. 
The style and stigma, which had been previously almost overlooked, have furnished M. Cassini with what 
appear to be beautiful distinguishing marks of his orders ; and it is upon these organs that much of the pecu- 
liarity of his arrangement depends. In the mean while, till it can be ascertained what the ultimate division 
of Compositae is likely to be, it has been considered more prudent in this work to indicate none of the divisions 
of either M. Cassini, or of his fellow-labourers in France or elsewhere. 
In a popular point of view, Syngenesia may be considered interesting in a high degree. It abounds in i)lants 
of ornament, all of which are, without exception, of easy cultivation. It is not necessary to particularize the 
merits of the brilliant varieties of the Dahlia, or of the Chinese Chrysanthemum, which are the chiefest orna- 
ments of every autumnal garden; nor to point out the beauty of the various tribes of Aster, Helianthus, 
Coreopsis, Xeranthemum, or Gnaphalium. These and an hundred others must be familiar to every lover of 
gardening. It is, however, worth remarking, that nearly all syngenesious plants are autumn flowers. In the 
tropics, many become trees of considerable dimensions ; in temperate climates, they are mostly herbaceous or 
low bushes. 
With regard to the qualities of syngenesious plants, considered economically or medicinally, it may be stated, 
that, whatever they may be, they consist in a bitter principle, and an oily secretion. But these vary in particular 
tribes. In some the bitter is combined with a resinous principle, by which its powers are increased 
in different degrees. In those plants in which the resin is found in small quantities only, and mixed with a 
bitter or astringent mucilage, tonic, stomachic, and febrifugal properties seem to be acquired, as in the camo- 
mile, the golden rod, the feverfew, and the Eupatorium perfoliatum ; and the stimulant powers of these plants 
appear to increase in proportion as the resin is abundant. Some kinds are anthelmintic, as the wormwood and 
tansy ; others are emmenagogue, as the feverfew, the yarrow, and various kinds of wormwoods. Certain spe- 
cies possess sudorific qualities, as the Eupatorium, the yarrow, the wormwood, and the marigold; others, 
again, are powerful diuretics, as Liatris ; while stimulating powers exist in considerable activity in others, as 
in the Sneezewort and Arnica. The Spilanthus, Anthemis, Pyrethrum, and some others, excite salivation. 
The Eupatorium Ayapana of Brazil, and the Guaco of Peru, which is another species of Eupatorium, are most 
powerful alexiterics. According to the analysis of M. Braconnot, the wormwood owes its bitterness to an 
extremely bitter animalized matter, which forms a little less than one fifth of its weight ; the same chemist 
also states that plant to contain a volatile oil, and an acid, apparently new, which is found in combination with 
potash. Before the perfect developement of the leaves, the bitter principle is so much diluted with insipid 
mucilage, that the young shoots of some of the thistle tribe, the Cardoon for example, are used for culinary 
purposes ; and it is probable, that it is owing to the small proportion which the bitter bears to the whole mass, 
that the receptacle of the artichoke, of the Onopordum, and of the cotton thistle, is found fit for food. The 
corollas of the Cardoon, and of many thistles, have the power of curdling milk. The juice of the lettuce and 
other cichoraceous plants is milky, bitter, astringent, and narcotic. In a wild state, the narcotic principle is so 
abundant, that the inspissated juice of Lactuca virosa has been used as a substitute for opium, and with much 
success. But under the effect of cultivation, the mucilage is so much more abundant than any other substance, 
that the same species often form well-known articles of wholesome and agreeable food. And, indeed, under 
any circumstances, wild or domesticated, the young shoots, when the narcotic principle is scarcely developed, are 
frequently eaten with safety ; it is for the same reason, namely, the incomplete formation of the bitter principle, 
and the superabundance of mucilage, on account of the absence of light, that the blanched leaves of cardoons 
and chiccory, and the white roots of the Scorzonera and the Salsafy, are capable of being eaten without inconve- 
nience. The seeds of all syngenesious plants abound in oil, which is expressed from those of the Madia of 
Chili, the Verbesina sativa, and the common sunflower. Owing to the difficulty of procuring this oil in a pure 
state, its virtues are not ascertained with much accuracy. They are generally believed to be slightly purgative 
and diaphoretic. 
Order 1. 
iEQUALIS. 
Flowers qf ike disk and ray all hermaphrodite, 
1620. Geropogon. Receptacle setose-paleaceous. Invol. many-leaved, simple, or with bracteoliB. Pericarps 
of disk with branched pappus, of the ray with five awns. 
1621. Tragopogou. Involucre simple, of many leaves. Receptacle naked, Pappus feathery, stipitate. Pe- 
ricarps longitudinally striated. 
1622. Troxifnon. Invol. oblong, conical, simple, or imbricated with unequal scales. Recept. naked, dotted. 
Pappus sessile, hairy. 
1623. Arnopogon. Recept. naked. Pappus feathery, stipitate. Involucre 1-leaved, 8-parted, turbinate. 
1624. Podospcrmum. Recept. warted. Pericarps cylindrical on a long stalk. Leaves finely cut. Otherwise 
as Scorzonera. 
1625. Scorzonera. Recept. naked. Pappus feathery, somewhat stalked. Invol. imbricated, with scales sca- 
rious at edge. 
1626. Picridium. Invol. ventricose at base, imbricated with broadish scales, membranous at edge. Pappus 
sessile, villous, simple. Pericarps 4-cornered, warted aci-oss. 
1627. Sonchus. Involucre imbricated, swelling at the base. Receptacle naked. Pappus simple, sessile. 
1628. Lactuca. Involucre imbricated, cylindrical, its scales with a membranous margin. Receptacle naked. 
J'ai)i)us simple, stipitate. 
1629. Chondrdla. Receptacle naked. Invol. with bracteolee. Pappus simple, stalked. Florets in many rows. 
Pericarps muricated. 
1630. Prenanthcs. Involucre with scales at the base. Receptacle naked. Pappus simple, sessile. Florets 
few. 
1631. Leontodon. Involucre with scales that are frequently lax and flaccid. Receptacle naked. Pappus 
simple, stipitate. 
1632. Apargia. Involucre imbricated with scales at the base. Receptacle naked, dotted. Pappus feathery, 
sessile, unequal. 
1633. Thrincia. Recept. favose. Pappus of the ray membranous, multifid, of the disk stalked, feathery. 
Invol. with 8 angles and 8 leaves. 
1634. Picris. Cal. double, the inner equal, the outer lax. Receptacle naked. Pappus feathery. Pericarps 
tiansvcrsely striated. 
16 3.5. Hieracium. Involucre ovate, imbricated. Receptacle nearly naked, dotted. Pappus simple, sessile. 
1636. Lagoscris has the characters of Crepis, but the pappus is stalked. 
1637. Borkhausia. Invol. oblong in two rows, the outer much shorter than the inner. Recept. alveolate. 
Pappus of the centre stalked, of the circurhference sessile or subsessiie. 
1638. Crepis. Involucre surrounded with deciduous scales, and at length swelling into protuberances. Re- 
ceptacle roughish. Pappus sessile. 
1639. Helminthia. Recept. naked. Invol. double : outer 8-leaved, equal j inner 5-leaved, as long as outer. 
Pericarps striated across. Pappus stalked, feathery. 
1640. Myoseris. Recept. i)aleaceous. Palece capillary. Invol. calyculated. Pappus hairy, sessile. 
1641. Tolpis. Recept. favose. Invol. with bracteola?, which are subulate, and as long as invol. Pappus of 
the ray toothed, of the disk with 2 or 4 awns. 
1642. Andryala. Recept. villous. Invol. many-parted, nearly equal, rounded. Pappus simple, sessile. 
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