The spadix of Arum, as also of the cocoa-nut palm, has been observed flattened out, apparently without increase in the number of organs.
When the blade of the leaf is suppressed it often happens that the stalk of the leaf is flattened, as it were, by compensation, and the petiole has then much the appearance of a flat ribbon (phyllode). This happens constantly in certain species of Acacia, Oxalis, &c., and has been attributed, but doubtless erroneously, to the fusion of the leaflets in an early state of development and in the position of rest.[365]
In some water plants, as Sagittaria, Alisma, Potamogeton, &c., the leaf-stalks are apt to get flattened out into ribbon-like bodies; and Olivier has figured and described a Cyclamen, called by him C. linearifolium, in which, owing to the suppression of the lamina, the petiole had become dilated into a ribbon-like expansion—déformation rubanée of Moquin.
FOOTNOTES:
[350] Moore, 'Nature Printed Ferns,' 8vo edition, vol. ii, p. 154, et p. 173.
[351] 'Flora (B. Z.),' 1821, vol. iv, p. 717, c. tab.
[352] Chavannes, 'Mon. Antirrh.'
[353] 'Bull. Soc. Bot. France,' t. vii, 1860, p. 877.
[354] Ibid., t. iv, 1857, p. 759.
[355] Jaeger, "De monstrosa folii Phœnicis dactyliferæ conformatione a Goetheo olim observata," 'Act. Acad. Leop. Car. Nat. Cur.,' vol. xvii, suppl., p. 293, c. tab. color. iv.