270 Wilhelm Bock 1969
DESCRIPTION. Structure. Cone-like inflorescence up to 20 cm long, about 8 cm wide tapered at both ends, consisting of substantial, broad stem, extending spiral-dichopodially stiff, curved bracts, surface covered by large numbers of upright or slightly slanted linear to lanceolate leaflets or scales, concentrating within axils or bracts into corolla, or campanula-like buds, attached to stem with dichopodially set, small scale-like appendages, terminating into one or two relatively large seeds; leaflets of support bracts and cover leaflets of buds fundamentally microphyllous or sterile; leaflets of axis within bud, macrophyllous or sterile. Inflorescence being dioecious or monoecious.
Fertile appendages. Bract leaflets believed to be microphyllous, straight, linear, to lanceolate, 4-6 mm long, averaging 1.0-1.3 mm in width, having pronounced mid-rib, attached in rows, upright or inclined to bract epidermis. Observable surface of bract leaflets smooth, occasionally indented by rows of roundish sporangia, 0.2-0.3 mm wide; cover leaflets of bud similar sized, but connected close spiral-dichopodially to bud shoot axis, terminating into smaller ovulate spiral-dichopodially set, somewhat overlapping sheathed scales, or leaflets, varying in size from 0.6-2.0 mm, terminating into one or two elongate, segment-shaped seeds, about 7 mm long, 3 mm wide, when mature; seed enclosed by integument and covered by rows of large papillose corpuscles, or teeth-like appendages, along straight margin.
Vascularization. Vascular bundles of stem peripherally arranged, amounting to about 50, followed by additional woody structure about 1 mm thick, surround- ing pith cylinder about 4 mm in diameter; stem bundles when extending upward diminishing in number by branching into bract series and bud series; bract bundle dichotomizing into about 4 branch bundles; bud bundle continuing into seed scale stem and seed scales proper.
ONTOGENETIC AND PHYLOGENETIC OBSERVATIONS
In trying to trace the origin of the new inflorescence three characters stand- ing out explicitly:
1. The cone-like inflorescence is spirally equipped with relatively long support bracts or base leaves, attached to a broad cone axis (of first order).
II. The microsporophylls appear to be minute, leaf-like appendages with a distinct mid-rib, attached to the surface and the sides of the bract in large numbers.
III. The leaf-like microphyllous appendages also form spirally in the axils of the bracts small single buds around a shoot axis (of second order), bearing on the same axis small falcate seed scales, sterile or fertile, terminally issuing 1 or 2 relatively large, symmetrical seeds.Cone structures displaying similar support bracts are known in the Lycopodiales and Coniferales. Neither group is close in relationship. In the Cycadales a staminate cone structure with similar numerous support bracts is prominent in the Cycas series. The bag-like microsporophylls are located on the lower side of the bract, while in the new species they are leaf-like, pointing toward their primitive origin. In the bennettitalian Williamsonia the sporophills appear to be radially united and the sporangia may be branched or tube-like as encountered in Cycadeoidean species.
Fig. 447 - Drawing of fig. 442, representing almost complete inflorescence, x 1.
Fig. 448 - Triassiflorites grandiflora, n. sp. Larger (male) inflorescence. Upper Triassic, Winterpock, Virginia; spec. 2811, x 1.
Fig. 458 - Triassiflorites grandiflora, n. sp. showing bracts with microsporangia attached to a few disheveled leaflets, x 1.