Nystroemiaceae

Ecology & Form

Stems

• Branches were probably woody with variability in its branching pattern

• Long and short shoots were differentiated

Leaves

• Vegetative leaf with a long petiole and a broad lamina with radiate reticulate venation

• Lamina with entire or undulate margin and cordate or tapering base

Reproductive Structures

• Frond-like ovuliferous organ

• The main axis forking with pinnate lateral branches bearing numerous small bicornute ovules at their tips. 

• Leafy/ovuliferous complex arising from leaf axil

• Ovuliferous organs attached in the axil of the petiole of leafy organ, or both organs crowded on a node

Nystroemia †

• Halle 1929; Wang & Pfefferkorn 2010

• Early - Late Permian of North China

• Seed plant with multi-order branching system

• Ovuliferous organ frond-like, with the main axis forking into two or more pinnate branches adaxially bearing numerous small bicornute ovules with zygomorphic symmetry

• Vegetative leaf with a long petiole; lamina reniform, basally cordate or tapering, entire or slightly undulate at the margin; veins numerous, finely diverging and reticulate.

• Leafy/ovuliferous complex arising from leaf axil, forming the last-order branches, which are alternative or opposite on the second-last-order axis

• Ovuliferous organs attached in the axil of the petiole of leafy organ, or both organs crowded on a node.

N. reniformis

• Wang et al. 2003

N. shouyangensis 

• Wang & Pfefferkorn 2010

• Middle - Late Permian (Capitanian–Wuchiapingian) of Shouyang, Shanxi, China

• Ovuliferous organ with the main axis forking into two or more pinnate-like branches adaxially bearing numerous small bicornute ovules with zygomorphic symmetry

• Vegetative leaf with a long petiole; lamina reniform, basally cordate, entire or slightly undulate at the margin; veins numerous, finely diverging and reticulate

• Leaves and ovuliferous organs attached to short shoots, forming the last-order branches