Fig. 42.—Altered arrangement of leaves of yew, Taxus baccata.
So, too, the alteration from verticillate to spiral, or vice versâ, may take place without any other notable change.[96] This may frequently be seen in Rhododendrons.
Displacement of the parts of the flower.—This subject is partly touched on in the chapters on solution, adhesion, and in those on hypertrophy, elongation, prolification, &c., so that in this place it is only requisite to offer a few general remarks, and to refer to other sections for further details. Morren, in referring to displacement of the floral organs, mentions an instance in a Fuchsia, wherein the four petals in place of being alternate with the sepals were placed in front of them, owing to the adhesion that had taken place between the petals and the stamens. He speaks of this transposition as metaphery.[97] The same author also gives an account of the displacement of several of the organs of the flower in Cypripedium insigne, the displacement being consequent, apparently, on a spiral torsion proceeding from right to left, and involving the complete or partial suppression of several of the organs of the flower. The dislocation of organs in a spiral direction led Morren to apply the term "speiranthie" to similar deviations from the usual construction. Changes of this kind among Orchidaceæ are by no means uncommon; the following may be cited by way of illustration. In a specimen of Oncidium cucullatum furnished me by Mr. Anderson, well known for his success as a cultivator of these plants, there was, associated with a cohesion of one sepal with another, and probably dependent on the same cause, a displacement of the sepals and petals—so that all were dragged out of place. This dislocation may be better appreciated by the accompanying formula than even by the woodcut. Let the usual arrangement be thus represented:
S
P ST P
L
S S
S standing for sepal, P for petal, L for lip, ST for stamen; then the dislocated form may be represented thus:
S
P P
T
S
S_S
L
Fig. 43.—Flower of Oncidium cucullatum, showing union of two lower sepals, displacement of column and lip, &c.