198 



Essential. Character. — Calyx superior, closely adhering to the ovarium, and un- 

 disting^ishable from it ; its limb either wanting, or membranous, divided into bristles, 

 palefe, hairs, or feathers, and called pappus. Corolla monopetalous, superior, usually deci- 

 duous, either ligulate or funnel-shaped ; in the latter case, 4- or 5-toothed, with a valvate 

 {estivation. Stamens equal in number to the teeth of the corolla, and alternate with them ; 

 the anthers cohering into a cylinder. Ovarium inferior, l-celled, with a single erect 

 ovulum; style simple; stigmas 2, either distinct or united. Fruit a small, indehisceiit, 

 dry pericarpium, crowned v/ith the limb of the calyx. Seed solita]:j'j erect ; embryo with a 

 taper, inferior radicle; albumen none — Herbaceous plmts or shrubs. Leaves alternate or 

 opposite, without stipula", usually simple. Floivers (cnWedJioi-ets) unisexual or hermaphro- 

 dite, collected in dense heads upon a common receptacle, surrounded by an involucrum. 

 BractecB either present or absent ; when present, stationed at the base of the florets, and 

 called palece of the receptacle. 



Affinities. One of the most natural and extensive families of the 

 vegetable kingdom, at all times recognised by its syngenesious stamens 

 and capitate flowers, Calycerese and Dipsacese, neighbouring orders, are 

 readily distinguished by their pendulous ovulum, and by the anthers being 

 either wholly or partially distinct. In proportion to its strict natural limits, 

 depending upon the uniformity of its characters, is the difficulty of sepa- 

 rating it into sections or subordinate divisions, a measure absolutely neces- 

 sary, on atcount of the vast number of species referable to the order. 

 Jussieu has three; Corymbiferee, the florets of which are flosculous in the 

 middle, and ligulate at the circumference ; Cichoracese, the florets of which 

 are all ligulate; and Cynarocephalse, all whose florets are flosculous; to 

 which has since been added a tribe called bilabiate. Linneeus divided them 

 according to. the sexes of the florets of different parts of the same head. 

 The former has been found unexceptionable, as far as it goes ; the latter 

 wholly unmanageable. Neither, however, have satisfied the views of modern 

 botanists, who have divided the order into a considerable number of sections, 

 to which each has given his own name ; so that this order has become a 

 perfect chaos to all who have not devoted years to its exclusive study. The 

 most important of those who have undertaken to remodel Compositoe, are 

 M. Cassini, who has written much upon them in the Dictionnaire des 

 Sciences Naturellcs, and elsewhere ; M. Kunth, Avhose arrangement will 

 be found in Humboldt's Nova Genera et Species Plantarum ; Mr. Don, 

 who has written several detached papers upon them; and Link, who has 

 an arrangement of his own in his Handbuch, vol. 1. p. 68.5. The most pro- 

 found writers upon their general structure are M. Cassini and Mr. Robert 

 Brown, whose paper in the 12th volume of the Transactions of the Linnean 

 Society is a masterpiece of careful investigation and acute reasoning, from 

 which I extract the following remarks : — 



" The whole of Compositse agree in two remarkable points of structure 

 of their corolla; which, taken together at least, materially assist in deter- 

 mining the limits of the class. The first of these is its valvular a2stivation ; 

 this, however, it has in common with several other families. The second 

 1 believe to be peculiar to the class, and hitherto unnoticed. It consists in 

 the disposition of its fasciculi of vessels or nerves; these, which at their 

 origin are generally equal in number to the divisions of the corolla, instead 

 of being placed opposite to these divisions, and passing through their axes 

 as in other plants, alternate with them ; each of the vessels at the top 

 of the tube dividing into two equal branches, running parallel to and near 

 the margins of the corresponding lacinitr, within whose apices they unite. 

 These, as they exist in the whole class, and arc in great part of it the only 

 vessels observable, may bo called primary. In several genera, however, other 

 vessels occur, alternating with the primary, and occupying the axes of the 

 laciniae; in some cases these seconchuy vessels lieing most distinctly visible 

 in the lacinitc, and becoming gradually fainter as they descend the tube, 



