��OF PLANTS CALLED COMPOSITE. 285
belong to the same genus, as their habit seems strongly to indicate, there can be no reason to separate from them Alcina of Cavanilles, erroneously considered by Willdenow as a species of Wedelia : and Dy sodium of Richard, pub- lished in Persoon's Synopsis, though differing from all the others in the form of its pericarpium and in that of its receptacle, must also be reduced to this genus. If, how- ever, the part described by Linnaeus as pappus in Melam- podium americanum be really such, and if the pericarpium itself vary so widely both in form and surface, it would be inconsistent with the principles of division generally adopted in Compositae, to unite all these plants into one genus, notwithstanding their great resemblance in habit as well as in the other parts of fructification; and it would be at least in vain to look for any combining character in this part of their structure.
A careful examination of the female flowers, especially in an early stage, removes this difficulty, by proving that the supposed external coat of the ovarium, with its various inequalities of surface, some of which have been described as pappus, is in reality an involute bractea or foliolum of the involucrum, like that of Microjjus, completely inclosing the ovarium, but from which in several species of the genus it is entirely, and in others in great part, distinct.
Craspedia
first appears in Forster's Prodromus Florulae Insularum Australium, where an essential generic character is given, but no description of the species. The genus is adopted and the character received without remark by Willdenow in his edition of Species Plantarum, and by Persoon in his Synopsis. Among George Forster's drawings of subjects of natural history made in Cook's second voyage, and qog now in the library of Sir Joseph Banks, there is a figure of this plant, from which it appears that he originally referred it to Stcehelina ; a proof that he had not at that time very carefully examined it. It is not improbable therefore that he afterwards proposed it as a distinct genus, belonging to
�� �
