Page:Journal of botany, British and foreign, Volume 9 (1871).djvu/242

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220

��ON HIPPOCRATEACEyE.

"We are glad to be enabled to give the following abstract of Mr. Miers' important paper, read before the Linnean Society on June 1st, based on a long and hiborious examination chiefly of the South American species of the Order. The history of the family shows the widely-divergent opinions of numerous botanists in regard to its atiinities, — the absolute want of know- ledge to guide these opinions at last culmiuiiting in the extinction of the Hippocrateacea by the authors of the new ' Genera Plantarum,' who have reduced it to a mere tribe of the Cdadracece; and not only so, but have amalgamated the several genera previously established into two, viz. Hip- pocratea and Salacia. The large amount of evidence here presented will, however, show its right to stand as a distinct Natural Order, having, in fact, little connection with CdastracetE in any well-digested system of arrangement.

The chief characters in its floral structure consist in having 5 sepals, 5 alternate petals imbricated in sestivation, and only 3 stamens (very rarely 5); the most important feature is the hypogynous disk, variable in shape, but constantly placed between the stamens and petals; the ovary is always superior, usually 3-locular, with definite anatropous ovules fixed in the axis. The mode of growth of the ovary varies greatly, and on these diflerences of development the author divided the family into three separate tribes: — i. Hippocratefe, where, in the progress of growth, the axis of the ovary never lengthens, remaining completely atrophied, the cells growing upwards vastly, sometimes to a hundred times the length of the axis at the maturity of the flower, thus producing 3 distinct capsules from a single ovary, which sometimes open 2-valvately and have winged seeds, or are indehiscent, with unciform seeds borne upon a carinated or alar support: upon such dift'erences five several genera are established. 2. Toiitelefe, distinguished by a drupaceous fruit, often of large size, the growth of an ovary wherein the axis lengthens commensurately with the cells, the fruit being thus 3-locular, with several seeds, which in most cases are covered by an ariUine, a fleshy complete coating, resolving itself into a mucilagi- nous pulp that envelopes the seeds: this tribe consists of eight genera. 3. Kippistice, remarkable for a floral development hitherto unknown among Dicotyledoues, but long ago described by Mr. Eobert Brown in Monocotyledones; here the stigmata, instead of alternating as usual with the stamens, and standing opposite to the cells of the ovary, are opposite to the stamens, and alternate with the cells of the ovary; the fruit is dru- paceous, variable in the position of the seeds, but with characters resem- bling those of Tontdiece: this tribe consists of three genera. There are thus seventeen genera in all, with well-marked characters, which were sepa- rately illustrated by as many drawings, each amply explained by analytical figures. The numerous facts here shown in regard to structure are, for the most part, hitherto undescribed, many being derived from analyses made of plants in the living state. In summarizing these details, the author pointed out the many salient points of distinction in the structure of Hippocratencece and Celastracece.

1. In the former, the stamens are generally anisomerous in regard to the petals (3 to 5); in the latter, they are constantly isomerous, with sta- mens equal to, or double the number of the petals.

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