266 Wilhelm Bock 1969
at the lower end a short section of the round stem, up to 1.2 cm wide, while the remaining part is covered spiral-dichopodially by 8-10 lengthwise rows of stiff, curved bracts, 4-5 cm long, about 25 in a row, averaging 250 bracts (figs. 442- 449). They are weakly falcately curved, terminating in a hook-like, upwardly turned point, which may form combined a protective cover. At the opposite end they expand into a decurrent base, which forms with that of the adjacent bracts a semi-circular space, harboring fertile flower buds (figs. 449, 455). The cross section of the bract is nearly elliptical to triangular, the sides forming 2 laterally slanted surfaces, which are longitudinally traversed by three or more, narrow, distinct grooves, interrupted by 3-4 nearly evenly spaced, rounded to elongated indentations. They are the attachment points of additional fertile buds, while the grooves represent the vascular supply lines (fig. 449). On some bracts of slightly differing cones, 2-3, thorn, or hook-like, dorsal sub-bracts (fig. 452), are evenly spaced along the dorsal bract surface, the rounded axils, or space thereof, being occupied by flower buds. The indentations, or perforations at the base of the axils and along the grooves, indicate the entrance of vascular supply to the female organs (fig. 452). This surface of the bract, which appears to be the skeletal support structure, is overlain by another thin layer with a finer striae, which are the supply lines to the microphyllous, or cover scales imbedded with their bases in the epiderinis of the bracts (figs. 449, 450).
The primary flower, either attached within the axil of two adjacent bracts, or the thorn-like sub-bracts, consists of an ovoid, corolla-like, closed bud of 12-15, slightly curved, lanceolate to linear leaflets or cover scales, having a length of 0.4-0.6 cm and a width of 1.5-2.3 rom, displaying a distinct mid rib. They are closely, spiral-dichopodially attached to the short base of a thin stem, representing an axillary shoot, developing above the base another series of tightly arranged, somewhat falcately shaped scale components, varying in length from 0.6-2.0 mm, believed to be seed scales, displaying in about the middle a small protrusion, probably representing a seed ansatz (fig. 456). At the tip of the axis a small gynoecium can be made out, consisting of two closely set, scale like components, developing one or two, probably oppositely arranged, seeds (figs. 455, 456, 451, A-D). Whether the axis is a true axillary shoot is uncertain, as the vascular systems of the flower buds within one support bract become united, while the vascularization of the bract seems to be unconnected with that of the former, but appears further down to unite within a main vascular bundle of the inflorescence axis. Nevertheless, the flower bud axis appears to represent a shoot with cover leaves around the base and seel scales, dormant or active, above. It indicates a trend from solitary, or few seeds to a more numerous ovulate development.
The remainder of the support bract surface is covered, particularly along the slanted sides, by sterile or fertile leaflets of the power bud, except that they are straight and attached directly to the epidermis, covering the support bract (figs. 449-450). The shape of the leaves is linear to slightly lanceolate with straight sides, bluntly pointed, 4-6 rom long, averaging 1.0-1.3 mm in width, closely arranged, overlapping usually half of each, lengthwise, narrowing toward the base into a short, neck-like attachment, which is inserted in a roundish hole of the bract epidermis, about 0.2 mm wide. In early stages the leaflets are closely appressed to the bracts, standing about perpendicular on the latter when mature, becoming disheveled er shed at later stages. A prominent feature is their strong
Fig. 442 - Triassiflorites grandiflora, n. sp. First inflorescence found. Upper Triassic, Winterpock, Virginia; Holotype 2301, x 1.
Fig. 443 - Enlargement, fig. 442, x 2.
Fig. 444 - Enlargement, fig. 442. Midaxial section of inflorescence, x 3.