142 MR. J. MIERS ON TWO GENERA OF PLANTS FROM CHILE. 
more internal leaflets bear the usual characters of petals. Were this distinction once 
admitted, and we were to conclude the normal arrangement to be ternary, and to allow 
the existence of an occasional binary combination, by the suppression of some of its parts, 
all the difficulties of its variable structure could be easily explained. In the solitary 
instance where the floral envelopes are only three (as in Königia), we might look upon 
it as an apetalous genus ; where they consist of six lobes, the three outer may be regarded 
as sepals, and the others as petals; or when nine, the six interior lobes as a double row 
of petals. In like manner, when five in number, we may conceive the two outer lobes 
(which in such cases are always more exterior) to be sepals, and the other three to be 
petals; when four or eight, the same distinction may be made by dividing them into 
binary series. This hypothesis, though only a modification of Mr. Bentham’s, will obvi- 
ously reduce the number of deviations from the normal rule. There does not indeed 
appear any reason why the floral envelopes of the Polygonacee should not be entitled to 
the same distinction into calyx and corolla, as is admitted, for instance, in the Polygalacee, 
where the calyx is often comparatively large and petaloid in texture, or as in the Portu- 
lacacee, where the same occurs, and where the number of sepals (different from that of 
the petals) is only two, in the same manner as, according to my view, exist in Polygonum, 
Fagopyrum, Coccoloba, Ceratogonum, Emex and Calligonum, in which last-mentioned 
genus the two exterior leaflets are larger and marcescent, showing the difference of their 
nature from the three petals, which remain persistent about the fruit. The same decadence 
of the sepals and persistence of the corolla occur also in the Portulacacee. In many other 
genera of the Polygonacee with six floral segments, the outer series, which are different. 
in texture, fall away, while the petals remain, investing the achenium. This view of the 
subject is much confirmed by the argument of Prof. Lindley*, where he offers very cogent 
reasons for associating the Polygonacee with the Caryophyllacee and the Portulacacee, 
with which orders they agree in the unsymmetrical inconstancy of their floral parts, in 
their sepals being often of petaloid texture, in the insertion of their stamens upon a hypo- 
gynous ring, quite free from the petals, in their somewhat stipitate ovarium, and in their 
farinaceous albumen enclosing a curved embryo. The Caryophyllacee have also their 
petioles somewhat vaginant. 
All the Eriogonee hitherto known accord with the normal rule, as they present six floral 
"mide in two series, nine stamens and three styles, but in the plant under considera- 
on, we have an unusual deviation from the general disposition, for here we find a quater- 
= arrangement, the involucre being generally 4-cleft, each flower having eight distinct, 
ery imbricated segments, eight stamens fixed upon the hypogynous support or gyno- 
phorus, and four styles and stigmata. In accordance with the views above suggested, 
I shall therefore consider the four outer segm ca : 
ents as a cal f fo 
lobes as a corolla of four yx of four sepals, and the inner 
digi petals. I will here remark, that in the same specimen I have 
ough rarely, that some of the involucres contain flowers in which their parts 
ins : FRANS. e. three sepals, three petals, six stamens, three styles and stigmata, but 
e involucre in such case is still 4-pointed. 
* Vegetable Kingdom, p. 50. 
