On the other hand, a polyp on the main stem may form a second bud which, instead of forming a pinnule by uniserial budding, produces by biserial budding a branch, from which pinnules arise as from the main stem (fig.
The sori are in the form of lines which branch out from the lower part of the pinnule in a fan-shaped manner.
They occur about midway between the central vein of the pinnuleand the margin of the leaf.
In their early days these clusters are distinctly in the form of lines, but after the throwing off of the indusia they rapidly mature and spread to such an extent that the whole of the under-surface of the pinnule is covered.
The whole margin of the pinnule is recurved, and from the edge of it is produced a very delicate whitish involucre, the whole forming a sort of pouch, as is admirably represented in the figure given by Fee.
Each pinnule has its edges so much recurved that the whole forms a sort of pouch, apparently filled with sporangia.
Illustration: Pinnuleof Brake showing reflexed edges] The titles Brake and Bracken are not always confined to their lawful owner.
Illustration: A pinnule of Maidenhair] But it is not easy to convince a friend that he has made a mistake in this regard.
Illustration: PLATE XV LADY FERN a Fruiting pinnule b Portion of same] The earliest fronds uncurl in May.
Illustration: PLATE V ROYAL FERN a Pinnule of Royal Fern b Showing veining] To the Royal Fern the old herbalists attributed many valuable qualities.
Sori on the edge of a pinnule terminating a vein; sporangia at the base of a long, bristle-like receptacle surrounded by a cup-shaped indusium.
The parts of the oak fern develop with great regularity, each pinna, pinnule and lobe having another exactly opposite to it nearly always.
Pinnules on the inferior side of the pinnæ often elongated, especially the lower pair, the pinnule nearest the rachis being usually the longest, at least in the lowest pinnæ.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "pinnule" in a variety of sentences. We hope that you will now be able to make sentences using this word.
