284 OBSERVATIONS ON PLANTS
the original formation of the petal. To establish these points, and consequently to prove that the parts in question are simple petals, and neither made up of two cohering envelopes, as M. Tristan supposes, nor of a calyx and abor- tive stamina, according to ]\Ir. Lindley's hypothesis, I shall describe their grachial development, as I have observed it in the common ZNlignonette, a plant in which all the anomalies that have led to this hypothesis exist in a very great degree.
The flower-bud of Reseda odorata, when it first becomes visible, has the divisions of its calyx slightly imbricate and entirely enclosing the other parts. In this stage the unguis of each of the two upper petals is extremely short, not broader than the base of the lamina, and is perfectly simple ; there being no rudiment of the inner process so remarkable in the fully expanded flower. The lamina at the same period may be termed palmato-pinnatifid, its divisions are all in the same plane, the terminating or middle segment is whitish or opaque, and several times longer than the lateral segments, which are semi-transparent. 230] Of the remaining four petals, the two middle are dimidiato-pinnatifid, their lateral segments existing only on the upper side ; and the two lower are undivided, being reduced to the middle segment or simple lamina. All the petals are erect, and do not cover the stamina in the slightest degree, either in this or in any other stage. The disk is hardly visible. The antherae. are longer than their fila- ments, of a pale-green colour ; those on the upper or pos- terior side of the flower being manifestly larger, and slightly tinged with brown. The pistillum is very minute and open at the top. In the next stage the calyx is no longer imbricate, but open ; the petals have their segments in nearly the same relative proportions ; the interior margin of the unguis is just visible; but the transition from unguis to lamina is still imperceptible ; the apex of the former not being broader than the base of the latter. It is unneces- sary to follow the development through the more advanced stages of the flower, the facts already stated being, in my opinion, absolutely conclusive as to the real nature of the
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