Hepaticae Amazonicæ et Andinœ... / Richard Spruce.

  • Spruce, Richard, 1817-1893.
Date:
1884,1885
Catalogue details

Licence: Public Domain Mark

Credit: Hepaticae Amazonicæ et Andinœ... / Richard Spruce. Source: Wellcome Collection.

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    the calyptra. This character of an inferior, or half-inferior calyptra occurring in several genera of Jungermaniece, is quite unknown in J ab niece. Pedicel of various lengths; in some genera (Porella, Herberta, Plagiochila, &c.) usually short, and very little emersed from the perianth, in all or most of the species; in others 60 or more cells long, and varying in actual length at maturity with the state of the atmo- sphere, being always more elongate when the weather is wet. The cells in contiguous longitudinal series are alternate, never opposite as in Lejeunea; although the pedicel of Cephalozia is of two concentric strata, the inner of which consists of four series of cells, whose inner walls form a cross on the section, similar to that seen in Lejeunea. The pedicel in all this' tribe is cylindrical at maturity, either only slightly or not at all enlarged at the apex; and is never, as in the Jubulece, dilated into a segment of a sphere, one-third the height of the whole globose capsule (into which it passes insensibly, and is usually considered to form an integral part of it). Capsule varying in the different genera from globose to cylindrical, often preserving nearly the same form and the same proportion of length to breadth throughout each genus. It is formed in almost every genus of at least two, but sometimes of several strata, whereof the outermost is twice (at least) the thickness of the inner strata, and consists of more regularly tesselate (subquadrate or subrectangular) cells. The cells of the innermost layer in many genera and species contain spiral fibre, very rarely perfect, but mostly reduced to half-rings (semi-annular) whose convexity is towards the axis of the capsule. In a few aberrant genera, of few species, tlie capsule is wholly (or in great part) unistratous, e.g., in Scalici. When ripe the capsule splits normally down to the base into four valves, which in a few species are again cloven, but unequally; rarely, and only in Fossombronia, is the dehiscence altogether irregular, and not (or only partly) along the valvular sutures. Elaters numerous—sometimes to be counted by thousands—produced on the whole inner surface of the capsule, usually slender and tortuous, narrower at each end (never truncate), and each includes two spiral fibres —rarely three or more—very rarely only one. When the capsule bursts, they mostly fall out all together, along with the spores. In some genera a few of the apical elaters, and in others a few of the basal ones, persist for some time after the bursting of the capsule, and retain a good many of the free elaters entangled in them, but finally fall away. These “ elater- holders,” as they have been called, are usually (but not always) shorter and wider than the free elaters, and do not generally agree with them in the number of included spirals. They exist in some genera where they have not been noticed, as for instance in Herberta (Sencltnera). Spores very numerous, and usually very minute, in only a few genera equalling those of the Jubulece-, nearly always globose. Subtribus I.—RADULErE. Platyphyllce Rees in Syn. Hep. 252, pro p. ; Jubulece N. Hep. Eur. III. Plantce pro more sat elatte, raro pusillae, virides vel flavo-virentes,