316 OBSERVATIONS ON THE NATURAL FAMILY
tinue distinct nearly to the base of the tube, where they converge and appear to unite with the middle nerve.
In Acicarpha and Boopis the filaments appear to me jointed as in Composites ; a character I have not been able to observe in the very few flowers which I have examined of Cahjcera.
In Acicarpha the florets of the circumference are herma- phrodite and apparently complete, the antherae containing pollen and the ovaria producing seed ; while those of the disk are male with an incomplete pistillum. Such an arrangement has not hitherto been observed in Composite, in which, wherever the central florets are male with an imperfect pistillum, those of the circumference are female with or without the rudiments of stamina.
The regularity in the order of expansion of flowers from the base to the top of the capitulum in Acicarpha tribu- hides and spatliulata, and the irregularity, approaching to the inverted order, which I have found to exist in both species of Boopis, seem to prove the capitulum to be simple in the former genus and compound in the latter, notwithstanding the great resemblance between their invo- lucra. The exact nature of its composition, however, in Boopis can only be satisfactorily determined in recent spe- cimens.
140] This irregular expansion in Boopis, which renders even the generic name improper, and at present the want of satisfactory characters to distinguish it from Calycera, are objections to the name M. Cassini has chosen for this family ; while that of Calycerece, which I have proposed, derived from the genus first described, and applicable to all the genera of the order, appears to me unexceptionable : especially as there seems no reason to doubt that the part which I have considered as calyx in Boopidece is really such ; its divisions being generally in equal number, and alternating with those of the corolla. It may be observed that a like alternation of the divisions of the pappus with the segments of the corolla obtains in those genera of Com- positae where both parts are in equal number. But in some cases, where the division of pappus is still further
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