Lign. 42.
Asterophyllites equisetiformis; nat.
Coal-shale. (Foss. Flor.)
ANNULARIA CARDIOCARPON.
The Annulariæ were herbaceous plants with verticillate foliage like the former, but the whorls were arranged on the same plane with the stems on which they grew, and their remains have a very elegant appearance when expanded in the coal schists. It is supposed that they were aquatic plants, and that the stems and leaves floated on the surface of the water.[118]
[118] Wond. p. 717. Petrifactions, pp. 27, 43, &c. For coloured figures see Pictorial Atlas, pl. v.
Sphenophyllum (wedge-shaped leaf). Lign. 43.—The fossil vegetables thus named, though somewhat resembling in their elegant verticillate foliage the Asterophyllites, differ essentially, and are regarded by M. Brongniart as herbaceous plants related to the Marsiliaceæ, or Pepper-worts. The leaves are triangular, truncated at the summit, and very deeply lobed and dentated. The fructification consists of sessile axillary or terminal spikes, composed of verticillate bracteæ, covering the receptacles. This mode of fructification resembles that of the Asterophyllites.[119]
[119] For details consult Tab. des Genres de Vég. Foss. p. 52.
Cardiocarpon.—[Lign. 44. fig. 1.]—These are small fossil fruits or seed-vessels, which much resemble those of the Thuja or Arbor-vitæ, and are so often found imbedded with masses of the foliage of Asterophyllites, that it is conjectured they belong to those plants. They occur in groups of from five to twenty, and evidently were didymous, i.e. grew in pairs. Fig. 1a. is an enlarged view, to show the surface left by the attachment of the twin-seed.