2. Calyptriform or hood-like pitchers, formed by the complete union of the margins, and falling off by a transverse fissure (as in the calyx of Escholtzia).

B. Polyphyllous.

1. Diphyllous, formed by the union of two leaves into a single cup, tube, or funnel, &c.

2. Triphyllous, formed by the union of three leaves.

Besides the above varieties of ascidia formed from the union of one or more leaves, there are others which seem to be the result of a peculiar excrescence or hypertrophy of the leaf. Such are some of the curious pitcher-like structures met with occasionally in the leaves of cabbages, lettuces, Aristolochia, &c. See Hypertrophy, cup-like deformities, &c.

In addition to other publications previously mentioned, reference may be made to the following treatises on the subject of ascidia:—Bonnet, 'Rech. Us. Feuilles,' p. 216, tab. xxvi, f. 1, Brassica; De Candolle, 'Trans. Hort. Soc.,' t. v, pl. 1, Brassica; Id., 'Org. Veget.,' I, 316; 'Bull. Soc. Bot. Fr.,' I, p. 62, Polygonatum; 'Bull. Acad. Belg.,' 1851, p. 591, Rosa; Hoffmann, 'Tijdschrift v. Natuur. Geschied.,' vol. viii, p. 318, tab. 9, Ceratonia; C. Mulder, 'Tijdschrift, &c.,' vol. vi, p. 106, tab. 5, 6, Trifolium, Mimosa, Staphylea;' Molkenboer,' p. 115, t. 4, Brassica.