Horal envelopes, from the other orders of the class, in which the quaternary or binary division is without exception; and it is especially remarkable in having the ovarium open even in its earliest state. from Crucifer® and Capparide®, the two families of the class to which they most nearly approach, Resedace® also differ in the apparent relation of the stigmata to the placent®. The stigmata in this order terminate the lobes of the pistillum,, and as these lobes are open sterile portions of the modified leaves, from the union .qf which in the undivided part 1 suppose the compound ovarium to originate, they necessarily alternate with the placent®. I have generally found, howev,eiy the upper part of each placenta covered by a fleshy or fungous process, which is connected with the margins of the lobes, and therefore with the stigmata, and is probably essential to the fecundation of the ovula. The singular apparent transposition of the placent® in Sesamoides of Tournefort, so well described by M. Tristan in his ingenious Memoir on the Affinities of Reseda *, appears to me necessarily connected with the extreme shortness-of the undivided base of the ovarium ; for in supposing this base to be elongated, the placent® would become parietal, and the ovula, which are actually resupinate*.would assume the direction usual in the order. M. De Jussieu, in his Genera Plantarum, has included Reseda in Capparide ®, and to this determination I believe he still adheres. M. Tristan, in the memoir referred to, is inclined to separate it as a family. intermediate between Passiflore® and Cistine®, but more nearly approaching to the latter. M. De Candolle, who first distinguished Reseda as an order under the name here adopted, in 18191 placed it between Polygale® and Droserace®, and consequently at no great distance from Capparide®. He must, since, however, have materially altered his opinion respecting i t ; for the order Resedace® is not included in the first or second part of his Prodromus, and I can find no observation respecting it in these two volumes. It is probable, therefore, that he may either intend to place it near Passiflore®, as suggested by M. Tristan, or, which is more likely, that he has adopted the hypothesis lately advanced, and ingeniously supported, by Mr. Lindley, respecting its structure and affinities t. According to this hypothesis, in Reseda the calyx of authors is an involu- * Annal, du Mus. d*Hist. N4t. l&. p. &92*' f Théor.Elem.ed. 2ì p. 244. • > \ Collect. Bot. tab. 22. • - c rum , its p e ta ls n e u t r a l flowers, a n d th e d îsk 'O r r ie c ta ty h e ro in e s t h e c â ly x ’ o f a f e r tile flo re t in th n c e n tr e : a n d ; as it d e d u c tio n from th i s f i ê w ’o f'itS ’ iSti'uCture, th e g e n u s h a s b e e n p la c e d n e a r Ë u p h o r b i a è e a s .''9 The points in the structure of Resèda! whichappèar tò héiVe led Mr. Hind- ley to this hypothesis, are the presence and appeàfstnc'é'of thè hÿpbgÿiioütfdisk, the anomalous structure of the petals; and the singular æstivàtlon of-thé flower ; but it is no slight confirmation of the correctness of M; dé1 Jussieu’s opinion, that all these anomalies occur in a greater or less degree in (‘appurideæ, knd have been found united in no other family of plants.1 The reiiiarkaH10J®stiva- tion of Reseda equally exists in Crateva, and in more than one subdivision oftlle genus Cleome; the hypogynous disk is developed in as great a degi'be in several Capparide® ; and an approximation to the same kind of irregularity in the petals occurs in two sections of Cleome. The analogical argument alone then might, perhaps, be regarded as conclusive against the hypothesis. But the question, as far as relates’to the petals, and consequently to the supposed composition of the flower, may lie- decided still more satisfactorily on other grounds. Both M.M. Tristan and Lindley regard the upper divided membranaceous part of the petal as an appendage to the lower, which is generally fleshy. On the other hand, I consider (bévanoli! aly to consist in the thickening, dilatation, and inner process of the1 lower portion, and that all these deviations from ordinary structure are changés Which take place after the original formation of the petal. To establish th'dsé’ points, and consequently to prove that the parts in question are simple pedals,1 and neither made up of two cohering envelopes; as Me Tristan supposes, fiior of a calyx and abortive stamina, according to M. • Lindley’S-hypôthdsis,'"I shall describe their gradual development, as I have observed it ’in •'the-common Mignonette; 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 opake, and several times longer than the lateral segments, which are semitransparent.
27f 24
To see the actual publication please follow the link above