Copy 1

A history of British ferns / By Edward Newman, F.L.S.

  • Edward Newman
Date:
1840
Catalogue details

Licence: Public Domain Mark

Credit: A history of British ferns / By Edward Newman, F.L.S. Source: Wellcome Collection.

    55/154 (page 15)
    is supposed to resemble a spread eagle, hence the specific name of Aquilina given it by Linneus. The frond is killed by the first frosts of autumn, however slight they may be; it instantly turns to a deep brown colour, but remains perfectly undecayed, and frequently in an erect position during the whole winter. The form of the frond is nearly that of an equilateral triangle, the base being somewhat but not materially the shortest of the three sides. The naked portion of the rachis is rather more than a third of the entire length of the frond; it is green, and rather pilose, rounded, and not ‘‘ angular and sharp-edged, wounding the hands severely,” as stated in the “ English Flora.” This statement must have crept in by some casual error, not being at all applicable to the present species. The pinnz are ' pinnate, and the pinnule regularly cleft to their midrib, the lobes being rounded and entire; the first pinnula on the upper side of each pinna being smaller, and often undivided. Under ordinary circumstances all the fronds are fertile, but the apex of each frond is commonly barren. In the fertile pinnulz the sides of the lobes are reflexed, the extreme margin being bleached and ragged, and forming a cover to the theca, ~— which are arranged in a marginal series, and as ~~ they approach maturity are gradually protruded ~ beyond this cover, and appear in two dark - lines, parallel to the midrib of the lobe, as —= represented on the left side of the adjoining | figure. ‘The transverse veins are placed alter- < nately on the midvein of the lobe; they are forked almost immediately on leaving the midvein, and the divisions are not _ unfrequently again divided before reaching the margin; all the veins are continued to the extreme margin of the green or leafy part of the lobe, and there enter a pulpy incrassated portion of the indusium, in which they become divided and dis- appear; and from this incrassated part the thece take their rise, as far as I can discover, in a continuous line; they are placed between two covers, which I will call indusia, although it is evident that both cannot be analogous to the indusium, in the genera Polystichum, &c. These two indusia may be detached with the thecw adhering to them: the exterior terminates in a marginal fringe, or series of capillary segments. Owing to the great and almost invincible elasticity of the reflexed portion