Table 1 Comparison of Schmeissneria to Ginkgoales, Gnetales, and angiosperms.
Characters | Schmeissneria [24,*] | Ginkgoales[24,31,32,45] | Gnetales[31-32,47,83-84] | Angiosperms[1] |
|---|---|---|---|---|
Long/short shoot | + | + | - | +/- |
Shoot articulate | - | - | + | +/- |
Phyllotaxis | Irregular spiral | Spiral on short shoot | Opposite/whorled | Opposite, whorled, spiral |
Leaf | Slender-cuneiform, obtuse apex | Fan-shaped, or cuneiform | Strap-like, triangular, linear or oval-shaped | Various |
Venation | Parallel | Dichotomous | Parallel or reticulate | Various |
Unisexuality | + | + | + (-) | +/- |
Reproductive axis articulate | - | - | + | +/- |
Bract | - | - | + | +/- (?) |
Bract arrangement | N/A | -(? bract scale seed complex) | Whorled/paired | Whorled, paired, or N/A |
Ovuliferous unit position | On peduncle tip, in pair | On peduncle tip, single, pair or more in group | In bract axil, one to many in a group | Terminal/axillary |
Ovuliferous unit with septum | + | - | - | +/- |
Ovule | Completely enclosed by central unit wall | Exposed through micropyle | Exposed through micropylar tube | Completely enclosed by carpel or secretion |
Micropylar tube | - | - | + | - |