Page:Miscellaneousbot01brow.djvu/65

From Wikisource
Jump to navigation Jump to search
This page has been validated.
BOTANY OF TERRA AUSTRALIS.
47

observed that I have found a projection of the stigma, [573 though certainly in a much less obvious degree, both in Agathis[1] and in a species of Podocarpus.

Towards this discovery, as extending to the Conifers more strictly so called, an important step was made in Pinus, by the accurate Schkuhr,[2] who first correctly described and figured the cupula of that genus, but who considered it as the ovarium itself and the two processes of its aperture as stigmata. Mr. Salisbury, who seems to have been unacquainted with Schkuhr's observations, published a few years afterwards,[3] the same opinion, which continued to be generally received till the appearance of the essays, already quoted, of Mirbel and Schoubert.

But these authors do not seem to be aware that certain plants of the order are even furnished with a double cupula. This is most remarkable in Podocarpus, in which the drupa is formed of this external cupula, whose aperture exists not at the apex, but very near its base or point of insertion. The inner cupula in this genus is in every stage entirely enclosed in the outer, and is in like manner inverted.

That this is the real structure of Podocarpus seems to be proved by that of the nearly related genus Dacrydium, hitherto so imperfectly understood. This genus has also a double cupula, the outer in the young state enclosing the inner, and both of them at this period being inverted, as in Podocarpus; but the inner in a more advanced stage acquires nearly an erect position, by rupturing one side of the external cupula, which, not continuing to increase proportionally in size, forms a cup surrounding the base only of the ripe fruit.

Three species of Podocarpus are found in Terra Australis; two of these exist in the colony of Port Jackson, the third was observed on the summit of the Table Mountain in Van Diemen's Island. Podocarpus asplenifolia of Labillardiere[4] is certainly not a Podocarpus, but either forms a distinct

  1. Salisbury in Linn. soc. transact. 8, p. 311. Pinus Dammara, Lamb, pin. p. 61, t. 38.
  2. Botan. handb. 3, p. 276, t. 308.
  3. Linn. soc. transact. 8, p. 308.
  4. Plant. Nov. Holl. 2, p. 71, t. 221.