Fig. 279. Valvate-involute æstivation of same in Vine-bower, Clematis Vitialla.
Involute, which is the same but the margins rolled inward, as in most of the large-flowered species of Clematis, Fig. [279].
Reduplicate, a rarer modification of valvate, is similar but with margins projecting outward.
Open, the parts not touching in the bud, as the calyx of Mignonette.
278. When the pieces overlap in the bud, it is in one of two ways; either every piece has one edge in and one edge out, or some pieces are wholly outside and others wholly inside. In the first case the æstivation is
Convolute, also named Contorted or Twisted, as in Fig. [280], a cross-section of a corolla very strongly thus convolute or rolled up together, and in the corolla of a Flax-flower (Fig. [281]), where the petals only moderately overlap in this way. Here one edge of every petal covers the next before it, while its other edge is covered by the next behind it. The other mode is the
Fig. 280. Convolute æstivation, as in the corolla-lobes of Oleander.