Page:A Voyage to Terra Australis Volume 2.djvu/557

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Natural Orders.]
APPENDIX.
543

of the seed, whether general or partial, is never found in the Dicotyledonous orders with monopetalous flowers, seems to have determined Jussieu[1] and other French botanists to remove Polygala, remarkable for its caruncula umbilicalis, from Rhinanthaceæ with which they had placed it, and to consider it, along with some nearly related genera, as forming a distinct polypetalous order. They appear to me however, not to have taken so correct a view of the structure of its Corolla as Adanson,[2] who very justly observes that both in this genus and Securidaca, which he rightly associates with it, the apparently monopetalous corolla is made up of three petals, united by means of the cohering filaments, the external sutures remaining visible; but Adanson himself has not observed the minute rudiments of two additional petals in Securidaca, the existence and position of which assist in explaining the nature of the irregularity in Polygala, where no such rudiments are found, but in which the corolla is in every other respect very similar. A much nearer approach to regularity, however, takes place in an unpublished genus, having 5 petals, which, though irregular, are of nearly equal size and similarly connected by the cohering filaments, likewise 5 in number. The essential characters of the order Polygaleæ to which Krameria, Monnina, Salomonia, and several unpublished genera also belong, consist in the hypogynous insertion of its corolla, which is always irregular, and frequently reduced to 3 petals, connected together by the cohering filaments, whose antheræ are simple and bursting only at the top.

About 30 species of this order are found in Terra Australis; these are either Comespermæ or Polygalæ, with a single species of Salomonia of

    liolis 2 lateralibus interioribus majoribus quandoque petaloideis; reliquorum duobus anterioribus (respectu spicæ) tertio postico. Petala 3–5, mediante tubo stamineo connexa, rarò distincta. Stamina hypogyna, 8 (nunc 3–4 vel 5): filamentis infernè connatis in tubulum hine apertum inde petala connectentem: Antheræ simplices, basi insertæ, poro apicis dehiscentes. Ovarium 2-loc. (quandoque 1–3 loc.) ovulis solitariis pendulis: Stylus 1: Stigma sæpe bilabiatum. Pericarpium sæpius capsulare, biloculare, bivalve, valvis medio septigeris: nunc Drupa vel Samara, 1–2-sperm. Semina pendula, umbilico (in capsularibus) strophiolato vel comoso. Embryo in axi albuminis carnosi vix longioris, quandoque (præsertim in pericarpiis clausis) deficientis. Herbæ vel Frutices, utplurimum glabri. Folia simplicia indivisa alterna exstipulata. Flores spicati sæpius terminales.

  1. Annales du mus. 14. p. 386, et seq.
  2. Fam. des Plantes, 2, p. 348.