On cephalozia (a genus of hepaticae) : its subgenera and some allied genera / by Richard Spruce.

  • Richard Spruce
Date:
1882
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Licence: Public Domain Mark

Credit: On cephalozia (a genus of hepaticae) : its subgenera and some allied genera / by Richard Spruce. Source: Wellcome Collection.

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    of the connate anthophyb, or flower-leaves, by whose union the (primi- tively) triphyllous perianth becomes a monophyllous colesule. But in Cephalozia the angles are the folds, or keels, of the complicate flower- leaves ; and as these leaves are 3, the third being postical, their union forms a 3-carinate perianth, whereof two keels are lateral, and the third keel is postical, or at the under side. This structure obtains in every Cephalozia^ and in several other genera—whether the leaves be succubous, tramsverse, or incubous—and it always originates in the same way. The sutures at the actual margins of the anthophyls are either plane or de- pressed, but not elevated into a keel, except in some species of Cephalo- ziella; and even in these, although the perianths may have normally more than three angles, other perianths are nearly always to be found— sometimes on the same plant—which have the angles reduced to three, and invariably with the third angle postical. [See below, under the description of the suhgenus Cephaloziella.'] But in Lophocolea the leaves and bracts—instead of being indexed on each side of their axis, and more or less complicate, as in Cephalozia, are either plane or .bent in the contrary direction—i.e. convex, or re- duiflicate {i.e. recurvo-canaliculate); and the anthophyls are united, either by the actual margin into a keel, or the suture is intramarginal, so that one of the two contiguous leaves projects beyond the suture into a limb or wing, which is a very common feature in tropical Lop>hocole(B, and exists also in the European L. hidentata var. alata. And as under- leaves are everywhere present, the postical anthophyl—similar to, but usually narrower than the lateral leaves—forms with these latter a trigonous perianth, in which (as is easily seen must be the case) the third angle is antical, and the third face postical; the exact contrary of what obtains in Cephalozia, where the perianth is plane in front, and the third angle is postical. This structure of the perianth of Lophocolea is always accompanied by, and may be considered to originate in, a more or less distinct lateral compression of the stem with the leaves. In Plagiochila, where the underleaves (if present at all) are mostly reduced to the grade of minute scale’s, the lateral compression reaches its limit, and the perianth becomes flattened and bivalvular—often winged at the antical suture of the valves (or anthophyls) by the overlapping edge of one of the two, and some- times also at the postical suture. The floral underleaf (where it exists)
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